Commit Graph

547 Commits

Author SHA1 Message Date
Tom Parkin
340bb1ac45 l2tp: improve API documentation in l2tp_core.h
* Improve the description of the key l2tp subsystem data structures.
 * Add high-level description of the main APIs for interacting with l2tp
   core.
 * Add documentation for the l2tp netlink session command callbacks.
 * Document the session pseudowire callbacks.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-30 16:45:31 -07:00
Tom Parkin
ca7885dbcd l2tp: tweak exports for l2tp_recv_common and l2tp_ioctl
All of the l2tp subsystem's exported symbols are exported using
EXPORT_SYMBOL_GPL, except for l2tp_recv_common and l2tp_ioctl.

These functions alone are not useful without the rest of the l2tp
infrastructure, so there's no practical benefit to these symbols using a
different export policy.

Change these exports to use EXPORT_SYMBOL_GPL for consistency with the
rest of l2tp.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-30 16:45:31 -07:00
Tom Parkin
2dedab6ff5 l2tp: remove build_header callback in struct l2tp_session
The structure of an L2TP data packet header varies depending on the
version of the L2TP protocol being used.

struct l2tp_session used to have a build_header callback to abstract
this difference away.  It's clearer to simply choose the correct
function to use when building the data packet (and we save on the
function pointer in the session structure).

This approach does mean dereferencing the parent tunnel structure in
order to determine the tunnel version, but we're doing that in the
transmit path in any case.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-30 16:45:31 -07:00
Tom Parkin
628703f59d l2tp: return void from l2tp_session_delete
l2tp_session_delete is used to schedule a session instance for deletion.
The function itself always returns zero, and none of its direct callers
check its return value, so have the function return void.

This change de-facto changes the l2tp netlink session_delete callback
prototype since all pseudowires currently use l2tp_session_delete for
their implementation of that operation.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-30 16:45:31 -07:00
Tom Parkin
52016e259b l2tp: don't export tunnel and session free functions
Tunnel and session instances are reference counted, and shouldn't be
directly freed by pseudowire code.

Rather than exporting l2tp_tunnel_free and l2tp_session_free, make them
private to l2tp_core.c, and export the refcount functions instead.

In order to do this, the refcount functions cannot be declared as
inline.  Since the codepaths which take and drop tunnel and session
references are not directly in the datapath this shouldn't cause
performance issues.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-30 16:45:31 -07:00
Tom Parkin
b2aecfe8e4 l2tp: don't export __l2tp_session_unhash
When __l2tp_session_unhash was first added it was used outside of
l2tp_core.c, but that's no longer the case.

As such, there's no longer a need to export the function.  Make it
private inside l2tp_core.c, and relocate it to avoid having to declare
the function prototype in l2tp_core.h.

Since the function is no longer used outside l2tp_core.c, remove the
"__" prefix since we don't need to indicate anything special about its
expected use to callers.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-30 16:45:31 -07:00
Tom Parkin
ab6934e084 l2tp: WARN_ON rather than BUG_ON in l2tp_session_free
l2tp_session_free called BUG_ON if the tunnel magic feather value wasn't
correct.  The intent of this was to catch lifetime bugs; for example
early tunnel free due to incorrect use of reference counts.

Since the tunnel magic feather being wrong indicates either early free
or structure corruption, we can avoid doing more damage by simply
leaving the tunnel structure alone.  If the tunnel refcount isn't
dropped when it should be, the tunnel instance will remain in the
kernel, resulting in the tunnel structure and socket leaking.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 17:19:14 -07:00
Tom Parkin
0dd62f69d8 l2tp: remove BUG_ON refcount value in l2tp_session_free
l2tp_session_free is only called by l2tp_session_dec_refcount when the
reference count reaches zero, so it's of limited value to validate the
reference count value in l2tp_session_free itself.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 17:19:14 -07:00
Tom Parkin
493048f5df l2tp: WARN_ON rather than BUG_ON in l2tp_session_queue_purge
l2tp_session_queue_purge is used during session shutdown to drop any
skbs queued for reordering purposes according to L2TP dataplane rules.

The BUG_ON in this function checks the session magic feather in an
attempt to catch lifetime bugs.

Rather than crashing the kernel with a BUG_ON, we can simply WARN_ON and
refuse to do anything more -- in the worst case this could result in a
leak.  However this is highly unlikely given that the session purge only
occurs from codepaths which have obtained the session by means of a lookup
via. the parent tunnel and which check the session "dead" flag to
protect against shutdown races.

While we're here, have l2tp_session_queue_purge return void rather than
an integer, since neither of the callsites checked the return value.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 17:19:14 -07:00
Tom Parkin
ebb4f5e6e4 l2tp: don't BUG_ON seqfile checks in l2tp_ppp
checkpatch advises that WARN_ON and recovery code are preferred over
BUG_ON which crashes the kernel.

l2tp_ppp has a BUG_ON check of struct seq_file's private pointer in
pppol2tp_seq_start prior to accessing data through that pointer.

Rather than crashing, we can simply bail out early and return NULL in
order to terminate the seq file processing in much the same way as we do
when reaching the end of tunnel/session instances to render.

Retain a WARN_ON to help trace possible bugs in this area.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 17:19:14 -07:00
Tom Parkin
1aa646ac71 l2tp: don't BUG_ON session magic checks in l2tp_ppp
checkpatch advises that WARN_ON and recovery code are preferred over
BUG_ON which crashes the kernel.

l2tp_ppp.c's BUG_ON checks of the l2tp session structure's "magic" field
occur in code paths where it's reasonably easy to recover:

 * In the case of pppol2tp_sock_to_session, we can return NULL and the
   caller will bail out appropriately.  There is no change required to
   any of the callsites of this function since they already handle
   pppol2tp_sock_to_session returning NULL.

 * In the case of pppol2tp_session_destruct we can just avoid
   decrementing the reference count on the suspect session structure.
   In the worst case scenario this results in a memory leak, which is
   preferable to a crash.

Convert these uses of BUG_ON to WARN_ON accordingly.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 17:19:14 -07:00
Tom Parkin
cd3e29b333 l2tp: remove BUG_ON in l2tp_tunnel_closeall
l2tp_tunnel_closeall is only called from l2tp_core.c, and it's easy
to statically analyse the code path calling it to validate that it
should never be passed a NULL tunnel pointer.

Having a BUG_ON checking the tunnel pointer triggers a checkpatch
warning.  Since the BUG_ON is of no value, remove it to avoid the
warning.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 17:19:14 -07:00
Tom Parkin
ce2f86ae25 l2tp: remove BUG_ON in l2tp_session_queue_purge
l2tp_session_queue_purge is only called from l2tp_core.c, and it's easy
to statically analyse the code paths calling it to validate that it
should never be passed a NULL session pointer.

Having a BUG_ON checking the session pointer triggers a checkpatch
warning.  Since the BUG_ON is of no value, remove it to avoid the
warning.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 17:19:14 -07:00
Tom Parkin
7a379558c2 l2tp: WARN_ON rather than BUG_ON in l2tp_dfs_seq_start
l2tp_dfs_seq_start had a BUG_ON to catch a possible programming error in
l2tp_dfs_seq_open.

Since we can easily bail out of l2tp_dfs_seq_start, prefer to do that
and flag the error with a WARN_ON rather than crashing the kernel.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 17:19:14 -07:00
Tom Parkin
95075150d0 l2tp: avoid multiple assignments
checkpatch warns about multiple assignments.

Update l2tp accordingly.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 17:19:14 -07:00
Christoph Hellwig
a7b75c5a8c net: pass a sockptr_t into ->setsockopt
Rework the remaining setsockopt code to pass a sockptr_t instead of a
plain user pointer.  This removes the last remaining set_fs(KERNEL_DS)
outside of architecture specific code.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> [ieee802154]
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-24 15:41:54 -07:00
Tom Parkin
70c05bfa4a l2tp: cleanup kzalloc calls
Passing "sizeof(struct blah)" in kzalloc calls is less readable,
potentially prone to future bugs if the type of the pointer is changed,
and triggers checkpatch warnings.

Tweak the kzalloc calls in l2tp which use this form to avoid the
warning.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23 11:54:40 -07:00
Tom Parkin
0787840dad l2tp: cleanup netlink tunnel create address handling
When creating an L2TP tunnel using the netlink API, userspace must
either pass a socket FD for the tunnel to use (for managed tunnels),
or specify the tunnel source/destination address (for unmanaged
tunnels).

Since source/destination addresses may be AF_INET or AF_INET6, the l2tp
netlink code has conditionally compiled blocks to support IPv6.

Rather than embedding these directly into l2tp_nl_cmd_tunnel_create
(where it makes the code difficult to read and confuses checkpatch to
boot) split the handling of address-related attributes into a separate
function.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23 11:54:40 -07:00
Tom Parkin
584ca31f46 l2tp: cleanup netlink send of tunnel address information
l2tp_nl_tunnel_send has conditionally compiled code to support AF_INET6,
which makes the code difficult to follow and triggers checkpatch
warnings.

Split the code out into functions to handle the AF_INET v.s. AF_INET6
cases, which both improves readability and resolves the checkpatch
warnings.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23 11:54:40 -07:00
Tom Parkin
26d9a27106 l2tp: check socket address type in l2tp_dfs_seq_tunnel_show
checkpatch warns about indentation and brace balancing around the
conditionally compiled code for AF_INET6 support in
l2tp_dfs_seq_tunnel_show.

By adding another check on the socket address type we can make the code
more readable while removing the checkpatch warning.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23 11:54:40 -07:00
Tom Parkin
6c0ec37b82 l2tp: cleanup unnecessary braces in if statements
These checks are all simple and don't benefit from extra braces to
clarify intent.  Remove them for easier-reading code.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23 11:54:40 -07:00
Tom Parkin
0febc7b3cd l2tp: cleanup comparisons to NULL
checkpatch warns about comparisons to NULL, e.g.

        CHECK: Comparison to NULL could be written "!rt"
        #474: FILE: net/l2tp/l2tp_ip.c:474:
        +       if (rt == NULL) {

These sort of comparisons are generally clearer and more readable
the way checkpatch suggests, so update l2tp accordingly.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-23 11:54:40 -07:00
Tom Parkin
efcd8c8540 l2tp: avoid precidence issues in L2TP_SKB_CB macro
checkpatch warned about the L2TP_SKB_CB macro's use of its argument: add
braces to avoid the problem.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22 18:08:39 -07:00
Tom Parkin
c0235fb39b l2tp: line-break long function prototypes
In l2tp_core.c both l2tp_tunnel_create and l2tp_session_create take
quite a number of arguments and have a correspondingly long prototype.

This is both quite difficult to scan visually, and triggers checkpatch
warnings.

Add a line break to make these function prototypes more readable.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22 18:08:39 -07:00
Tom Parkin
bdf9866e4b l2tp: prefer seq_puts for unformatted output
checkpatch warns about use of seq_printf where seq_puts would do.

Modify l2tp_debugfs accordingly.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22 18:08:39 -07:00
Tom Parkin
dbf82f3fac l2tp: prefer using BIT macro
Use BIT(x) rather than (1<<x), reported by checkpatch.pl.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22 18:08:39 -07:00
Tom Parkin
bef04d162c l2tp: add identifier name in function pointer prototype
Reported by checkpatch:

        "WARNING: function definition argument 'struct sock *'
         should also have an identifier name"

Add an identifier name to help document the prototype.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22 18:08:39 -07:00
Tom Parkin
0864e331fd l2tp: cleanup suspect code indent
l2tp_core has conditionally compiled code in l2tp_xmit_skb for IPv6
support.  The structure of this code triggered a checkpatch warning
due to incorrect indentation.

Fix up the indentation to address the checkpatch warning.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22 18:08:39 -07:00
Tom Parkin
8ce9825a59 l2tp: cleanup wonky alignment of line-broken function calls
Arguments should be aligned with the function call open parenthesis as
per checkpatch.  Tweak some function calls which were not aligned
correctly.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22 18:08:39 -07:00
Tom Parkin
9f7da9a0e3 l2tp: cleanup difficult-to-read line breaks
Some l2tp code had line breaks which made the code more difficult to
read.  These were originally motivated by the 80-character line width
coding guidelines, but were actually a negative from the perspective of
trying to follow the code.

Remove these linebreaks for clearer code, even if we do exceed 80
characters in width in some places.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22 18:08:39 -07:00
Tom Parkin
20dcb1107a l2tp: cleanup comments
Modify some l2tp comments to better adhere to kernel coding style, as
reported by checkpatch.pl.

Add descriptive comments for the l2tp per-net spinlocks to document
their use.

Fix an incorrect comment in l2tp_recv_common:

RFC2661 section 5.4 states that:

"The LNS controls enabling and disabling of sequence numbers by sending a
data message with or without sequence numbers present at any time during
the life of a session."

l2tp handles this correctly in l2tp_recv_common, but the comment around
the code was incorrect and confusing.  Fix up the comment accordingly.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22 18:08:39 -07:00
Tom Parkin
b71a61ccfe l2tp: cleanup whitespace use
Fix up various whitespace issues as reported by checkpatch.pl:

 * remove spaces around operators where appropriate,
 * add missing blank lines following declarations,
 * remove multiple blank lines, or trailing blank lines at the end of
   functions.

Signed-off-by: Tom Parkin <tparkin@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-22 18:08:39 -07:00
Christoph Hellwig
3021ad5299 net/ipv6: remove compat_ipv6_{get,set}sockopt
Handle the few cases that need special treatment in-line using
in_compat_syscall().  This also removes all the now unused
compat_{get,set}sockopt methods.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:16:41 -07:00
Christoph Hellwig
b6238c04c0 net/ipv4: remove compat_ip_{get,set}sockopt
Handle the few cases that need special treatment in-line using
in_compat_syscall().

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:16:41 -07:00
Christoph Hellwig
8c918ffbba net: remove compat_sock_common_{get,set}sockopt
Add the compat handling to sock_common_{get,set}sockopt instead,
keyed of in_compat_syscall().  This allow to remove the now unused
->compat_{get,set}sockopt methods from struct proto_ops.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-19 18:16:40 -07:00
David S. Miller
71930d6102 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
All conflicts seemed rather trivial, with some guidance from
Saeed Mameed on the tc_ct.c one.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-11 00:46:00 -07:00
Xin Long
27d5332366 l2tp: remove skb_dst_set() from l2tp_xmit_skb()
In the tx path of l2tp, l2tp_xmit_skb() calls skb_dst_set() to set
skb's dst. However, it will eventually call inet6_csk_xmit() or
ip_queue_xmit() where skb's dst will be overwritten by:

   skb_dst_set_noref(skb, dst);

without releasing the old dst in skb. Then it causes dst/dev refcnt leak:

  unregister_netdevice: waiting for eth0 to become free. Usage count = 1

This can be reproduced by simply running:

  # modprobe l2tp_eth && modprobe l2tp_ip
  # sh ./tools/testing/selftests/net/l2tp.sh

So before going to inet6_csk_xmit() or ip_queue_xmit(), skb's dst
should be dropped. This patch is to fix it by removing skb_dst_set()
from l2tp_xmit_skb() and moving skb_dst_drop() into l2tp_xmit_core().

Fixes: 3557baabf2 ("[L2TP]: PPP over L2TP driver core")
Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: James Chapman <jchapman@katalix.com>
Tested-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-08 15:24:33 -07:00
Luc Van Oostenryck
433f17a93c l2tp: fix l2tp_eth_dev_xmit()'s return type
The method ndo_start_xmit() is defined as returning an 'netdev_tx_t',
which is a typedef for an enum type, but the implementation in this
driver returns an 'int'.

Fix this by returning 'netdev_tx_t' in this driver too.

Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-06-28 20:52:53 -07:00
Masahiro Yamada
a7f7f6248d treewide: replace '---help---' in Kconfig files with 'help'
Since commit 84af7a6194 ("checkpatch: kconfig: prefer 'help' over
'---help---'"), the number of '---help---' has been gradually
decreasing, but there are still more than 2400 instances.

This commit finishes the conversion. While I touched the lines,
I also fixed the indentation.

There are a variety of indentation styles found.

  a) 4 spaces + '---help---'
  b) 7 spaces + '---help---'
  c) 8 spaces + '---help---'
  d) 1 space + 1 tab + '---help---'
  e) 1 tab + '---help---'    (correct indentation)
  f) 1 tab + 1 space + '---help---'
  g) 1 tab + 2 spaces + '---help---'

In order to convert all of them to 1 tab + 'help', I ran the
following commend:

  $ find . -name 'Kconfig*' | xargs sed -i 's/^[[:space:]]*---help---/\thelp/'

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2020-06-14 01:57:21 +09:00
David S. Miller
1806c13dc2 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
xdp_umem.c had overlapping changes between the 64-bit math fix
for the calculation of npgs and the removal of the zerocopy
memory type which got rid of the chunk_size_nohdr member.

The mlx5 Kconfig conflict is a case where we just take the
net-next copy of the Kconfig entry dependency as it takes on
the ESWITCH dependency by one level of indirection which is
what the 'net' conflicting change is trying to ensure.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-31 17:48:46 -07:00
Eric Dumazet
d9a81a2252 l2tp: add sk_family checks to l2tp_validate_socket
syzbot was able to trigger a crash after using an ISDN socket
and fool l2tp.

Fix this by making sure the UDP socket is of the proper family.

BUG: KASAN: slab-out-of-bounds in setup_udp_tunnel_sock+0x465/0x540 net/ipv4/udp_tunnel.c:78
Write of size 1 at addr ffff88808ed0c590 by task syz-executor.5/3018

CPU: 0 PID: 3018 Comm: syz-executor.5 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x188/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:382
 __kasan_report.cold+0x20/0x38 mm/kasan/report.c:511
 kasan_report+0x33/0x50 mm/kasan/common.c:625
 setup_udp_tunnel_sock+0x465/0x540 net/ipv4/udp_tunnel.c:78
 l2tp_tunnel_register+0xb15/0xdd0 net/l2tp/l2tp_core.c:1523
 l2tp_nl_cmd_tunnel_create+0x4b2/0xa60 net/l2tp/l2tp_netlink.c:249
 genl_family_rcv_msg_doit net/netlink/genetlink.c:673 [inline]
 genl_family_rcv_msg net/netlink/genetlink.c:718 [inline]
 genl_rcv_msg+0x627/0xdf0 net/netlink/genetlink.c:735
 netlink_rcv_skb+0x15a/0x410 net/netlink/af_netlink.c:2469
 genl_rcv+0x24/0x40 net/netlink/genetlink.c:746
 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline]
 netlink_unicast+0x537/0x740 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x882/0xe10 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:672
 ____sys_sendmsg+0x6e6/0x810 net/socket.c:2352
 ___sys_sendmsg+0x100/0x170 net/socket.c:2406
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca29
Code: 0d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007effe76edc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004fe1c0 RCX: 000000000045ca29
RDX: 0000000000000000 RSI: 0000000020000240 RDI: 0000000000000005
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000094e R14: 00000000004d5d00 R15: 00007effe76ee6d4

Allocated by task 3018:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 __kasan_kmalloc mm/kasan/common.c:495 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:468
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x161/0x7a0 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 sk_prot_alloc+0x223/0x2f0 net/core/sock.c:1612
 sk_alloc+0x36/0x1100 net/core/sock.c:1666
 data_sock_create drivers/isdn/mISDN/socket.c:600 [inline]
 mISDN_sock_create+0x272/0x400 drivers/isdn/mISDN/socket.c:796
 __sock_create+0x3cb/0x730 net/socket.c:1428
 sock_create net/socket.c:1479 [inline]
 __sys_socket+0xef/0x200 net/socket.c:1521
 __do_sys_socket net/socket.c:1530 [inline]
 __se_sys_socket net/socket.c:1528 [inline]
 __x64_sys_socket+0x6f/0xb0 net/socket.c:1528
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

Freed by task 2484:
 save_stack+0x1b/0x40 mm/kasan/common.c:49
 set_track mm/kasan/common.c:57 [inline]
 kasan_set_free_info mm/kasan/common.c:317 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:456
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x109/0x2b0 mm/slab.c:3757
 kvfree+0x42/0x50 mm/util.c:603
 __free_fdtable+0x2d/0x70 fs/file.c:31
 put_files_struct fs/file.c:420 [inline]
 put_files_struct+0x248/0x2e0 fs/file.c:413
 exit_files+0x7e/0xa0 fs/file.c:445
 do_exit+0xb04/0x2dd0 kernel/exit.c:791
 do_group_exit+0x125/0x340 kernel/exit.c:894
 get_signal+0x47b/0x24e0 kernel/signal.c:2739
 do_signal+0x81/0x2240 arch/x86/kernel/signal.c:784
 exit_to_usermode_loop+0x26c/0x360 arch/x86/entry/common.c:161
 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:279 [inline]
 do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305
 entry_SYSCALL_64_after_hwframe+0x49/0xb3

The buggy address belongs to the object at ffff88808ed0c000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 1424 bytes inside of
 2048-byte region [ffff88808ed0c000, ffff88808ed0c800)
The buggy address belongs to the page:
page:ffffea00023b4300 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea0002838208 ffffea00015ba288 ffff8880aa000e00
raw: 0000000000000000 ffff88808ed0c000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808ed0c480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808ed0c500: 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88808ed0c580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                         ^
 ffff88808ed0c600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808ed0c680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

Fixes: 6b9f34239b ("l2tp: fix races in tunnel creation")
Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Cc: Guillaume Nault <gnault@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-30 21:56:55 -07:00
Eric Dumazet
02c71b144c l2tp: do not use inet_hash()/inet_unhash()
syzbot recently found a way to crash the kernel [1]

Issue here is that inet_hash() & inet_unhash() are currently
only meant to be used by TCP & DCCP, since only these protocols
provide the needed hashinfo pointer.

L2TP uses a single list (instead of a hash table)

This old bug became an issue after commit 6102365876
("bpf: Add new cgroup attach type to enable sock modifications")
since after this commit, sk_common_release() can be called
while the L2TP socket is still considered 'hashed'.

general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 PID: 7063 Comm: syz-executor654 Not tainted 5.7.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e dd 04 00 00 48 8d 7d 08 44 8b 73 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 55 05 00 00 48 8d 7d 14 4c 8b 6d 08 48 b8 00 00
RSP: 0018:ffffc90001777d30 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88809a6df940 RCX: ffffffff8697c242
RDX: 0000000000000001 RSI: ffffffff8697c251 RDI: 0000000000000008
RBP: 0000000000000000 R08: ffff88809f3ae1c0 R09: fffffbfff1514cc1
R10: ffffffff8a8a6607 R11: fffffbfff1514cc0 R12: ffff88809a6df9b0
R13: 0000000000000007 R14: 0000000000000000 R15: ffffffff873a4d00
FS:  0000000001d2b880(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000006cd090 CR3: 000000009403a000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 sk_common_release+0xba/0x370 net/core/sock.c:3210
 inet_create net/ipv4/af_inet.c:390 [inline]
 inet_create+0x966/0xe00 net/ipv4/af_inet.c:248
 __sock_create+0x3cb/0x730 net/socket.c:1428
 sock_create net/socket.c:1479 [inline]
 __sys_socket+0xef/0x200 net/socket.c:1521
 __do_sys_socket net/socket.c:1530 [inline]
 __se_sys_socket net/socket.c:1528 [inline]
 __x64_sys_socket+0x6f/0xb0 net/socket.c:1528
 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x441e29
Code: e8 fc b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdce184148 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441e29
RDX: 0000000000000073 RSI: 0000000000000002 RDI: 0000000000000002
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000402c30 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 23b6578228ce553e ]---
RIP: 0010:inet_unhash+0x11f/0x770 net/ipv4/inet_hashtables.c:600
Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e dd 04 00 00 48 8d 7d 08 44 8b 73 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 55 05 00 00 48 8d 7d 14 4c 8b 6d 08 48 b8 00 00
RSP: 0018:ffffc90001777d30 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88809a6df940 RCX: ffffffff8697c242
RDX: 0000000000000001 RSI: ffffffff8697c251 RDI: 0000000000000008
RBP: 0000000000000000 R08: ffff88809f3ae1c0 R09: fffffbfff1514cc1
R10: ffffffff8a8a6607 R11: fffffbfff1514cc0 R12: ffff88809a6df9b0
R13: 0000000000000007 R14: 0000000000000000 R15: ffffffff873a4d00
FS:  0000000001d2b880(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000006cd090 CR3: 000000009403a000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Fixes: 0d76751fad ("l2tp: Add L2TPv3 IP encapsulation (no UDP) support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Cc: Andrii Nakryiko <andriin@fb.com>
Reported-by: syzbot+3610d489778b57cc8031@syzkaller.appspotmail.com
2020-05-30 21:55:16 -07:00
Christoph Hellwig
3986912f6a ipv6: move SIOCADDRT and SIOCDELRT handling into ->compat_ioctl
To prepare removing the global routing_ioctl hack start lifting the code
into a newly added ipv6 ->compat_ioctl handler.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-18 17:35:02 -07:00
Cong Wang
1a33e10e4a net: partially revert dynamic lockdep key changes
This patch reverts the folowing commits:

commit 064ff66e2b
"bonding: add missing netdev_update_lockdep_key()"

commit 53d374979e
"net: avoid updating qdisc_xmit_lock_key in netdev_update_lockdep_key()"

commit 1f26c0d3d2
"net: fix kernel-doc warning in <linux/netdevice.h>"

commit ab92d68fc2
"net: core: add generic lockdep keys"

but keeps the addr_list_lock_key because we still lock
addr_list_lock nestedly on stack devices, unlikely xmit_lock
this is safe because we don't take addr_list_lock on any fast
path.

Reported-and-tested-by: syzbot+aaa6fa4949cc5d9b7b25@syzkaller.appspotmail.com
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-04 12:05:56 -07:00
Michael Weiß
2abe05234f l2tp: Allow management of tunnels and session in user namespace
Creation and management of L2TPv3 tunnels and session through netlink
requires CAP_NET_ADMIN. However, a process with CAP_NET_ADMIN in a
non-initial user namespace gets an EPERM due to the use of the
genetlink GENL_ADMIN_PERM flag. Thus, management of L2TP VPNs inside
an unprivileged container won't work.

We replaced the GENL_ADMIN_PERM by the GENL_UNS_ADMIN_PERM flag
similar to other network modules which also had this problem, e.g.,
openvswitch (commit 4a92602aa1 "openvswitch: allow management from
inside user namespaces") and nl80211 (commit 5617c6cd6f "nl80211:
Allow privileged operations from user namespaces").

I tested this in the container runtime trustm3 (trustm3.github.io)
and was able to create l2tp tunnels and sessions in unpriviliged
(user namespaced) containers using a private network namespace.
For other runtimes such as docker or lxc this should work, too.

Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-08 14:30:46 -07:00
Gustavo A. R. Silva
af71b090c8 l2tp: Replace zero-length array with flexible-array member
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:

struct foo {
        int stuff;
        struct boo array[];
};

By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.

Also, notice that, dynamic memory allocations won't be affected by
this change:

"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]

Lastly, fix the following checkpatch warning:
CHECK: Prefer kernel type 'u8' over 'uint8_t'
#50: FILE: net/l2tp/l2tp_core.h:119:
+	uint8_t			priv[];	/* private data */

This issue was found with the help of Coccinelle.

[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-28 12:08:37 -08:00
Ridge Kennedy
0d0d9a388a l2tp: Allow duplicate session creation with UDP
In the past it was possible to create multiple L2TPv3 sessions with the
same session id as long as the sessions belonged to different tunnels.
The resulting sessions had issues when used with IP encapsulated tunnels,
but worked fine with UDP encapsulated ones. Some applications began to
rely on this behaviour to avoid having to negotiate unique session ids.

Some time ago a change was made to require session ids to be unique across
all tunnels, breaking the applications making use of this "feature".

This change relaxes the duplicate session id check to allow duplicates
if both of the colliding sessions belong to UDP encapsulated tunnels.

Fixes: dbdbc73b44 ("l2tp: fix duplicate session creation")
Signed-off-by: Ridge Kennedy <ridge.kennedy@alliedtelesis.co.nz>
Acked-by: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-04 12:35:49 +01:00
Xu Wang
d2e9d229cf l2tp: Remove redundant BUG_ON() check in l2tp_pernet
Passing NULL to l2tp_pernet causes a crash via BUG_ON.
Dereferencing net in net_generic() also has the same effect.
This patch removes the redundant BUG_ON check on the same parameter.

Signed-off-by: Xu Wang <vulab@iscas.ac.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-03 12:26:07 -08:00
Sabrina Dubroca
c4e85f73af net: ipv6: add net argument to ip6_dst_lookup_flow
This will be used in the conversion of ipv6_stub to ip6_dst_lookup_flow,
as some modules currently pass a net argument without a socket to
ip6_dst_lookup. This is equivalent to commit 343d60aada ("ipv6: change
ipv6_stub_impl.ipv6_dst_lookup to take net argument").

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-04 12:27:12 -08:00
Taehee Yoo
ab92d68fc2 net: core: add generic lockdep keys
Some interface types could be nested.
(VLAN, BONDING, TEAM, MACSEC, MACVLAN, IPVLAN, VIRT_WIFI, VXLAN, etc..)
These interface types should set lockdep class because, without lockdep
class key, lockdep always warn about unexisting circular locking.

In the current code, these interfaces have their own lockdep class keys and
these manage itself. So that there are so many duplicate code around the
/driver/net and /net/.
This patch adds new generic lockdep keys and some helper functions for it.

This patch does below changes.
a) Add lockdep class keys in struct net_device
   - qdisc_running, xmit, addr_list, qdisc_busylock
   - these keys are used as dynamic lockdep key.
b) When net_device is being allocated, lockdep keys are registered.
   - alloc_netdev_mqs()
c) When net_device is being free'd llockdep keys are unregistered.
   - free_netdev()
d) Add generic lockdep key helper function
   - netdev_register_lockdep_key()
   - netdev_unregister_lockdep_key()
   - netdev_update_lockdep_key()
e) Remove unnecessary generic lockdep macro and functions
f) Remove unnecessary lockdep code of each interfaces.

After this patch, each interface modules don't need to maintain
their lockdep keys.

Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-24 14:53:48 -07:00
Florian Westphal
895b5c9f20 netfilter: drop bridge nf reset from nf_reset
commit 174e23810c
("sk_buff: drop all skb extensions on free and skb scrubbing") made napi
recycle always drop skb extensions.  The additional skb_ext_del() that is
performed via nf_reset on napi skb recycle is not needed anymore.

Most nf_reset() calls in the stack are there so queued skb won't block
'rmmod nf_conntrack' indefinitely.

This removes the skb_ext_del from nf_reset, and renames it to a more
fitting nf_reset_ct().

In a few selected places, add a call to skb_ext_reset to make sure that
no active extensions remain.

I am submitting this for "net", because we're still early in the release
cycle.  The patch applies to net-next too, but I think the rename causes
needless divergence between those trees.

Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2019-10-01 18:42:15 +02:00
Arnd Bergmann
055d88242a compat_ioctl: pppoe: fix PPPOEIOCSFWD handling
Support for handling the PPPOEIOCSFWD ioctl in compat mode was added in
linux-2.5.69 along with hundreds of other commands, but was always broken
sincen only the structure is compatible, but the command number is not,
due to the size being sizeof(size_t), or at first sizeof(sizeof((struct
sockaddr_pppox)), which is different on 64-bit architectures.

Guillaume Nault adds:

  And the implementation was broken until 2016 (see 29e73269aa ("pppoe:
  fix reference counting in PPPoE proxy")), and nobody ever noticed. I
  should probably have removed this ioctl entirely instead of fixing it.
  Clearly, it has never been used.

Fix it by adding a compat_ioctl handler for all pppoe variants that
translates the command number and then calls the regular ioctl function.

All other ioctl commands handled by pppoe are compatible between 32-bit
and 64-bit, and require compat_ptr() conversion.

This should apply to all stable kernels.

Acked-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-30 14:42:13 -07:00
Willem de Bruijn
59c820b231 ipv6: elide flowlabel check if no exclusive leases exist
Processes can request ipv6 flowlabels with cmsg IPV6_FLOWINFO.
If not set, by default an autogenerated flowlabel is selected.

Explicit flowlabels require a control operation per label plus a
datapath check on every connection (every datagram if unconnected).
This is particularly expensive on unconnected sockets multiplexing
many flows, such as QUIC.

In the common case, where no lease is exclusive, the check can be
safely elided, as both lease request and check trivially succeed.
Indeed, autoflowlabel does the same even with exclusive leases.

Elide the check if no process has requested an exclusive lease.

fl6_sock_lookup previously returns either a reference to a lease or
NULL to denote failure. Modify to return a real error and update
all callers. On return NULL, they can use the label and will elide
the atomic_dec in fl6_sock_release.

This is an optimization. Robust applications still have to revert to
requesting leases if the fast path fails due to an exclusive lease.

Changes RFC->v1:
  - use static_key_false_deferred to rate limit jump label operations
    - call static_key_deferred_flush to stop timers on exit
  - move decrement out of RCU context
  - defer optimization also if opt data is associated with a lease
  - updated all fp6_sock_lookup callers, not just udp

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-07-08 19:38:03 -07:00
David S. Miller
92ad6325cb Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Minor SPDX change conflict.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-22 08:59:24 -04:00
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Greg Kroah-Hartman
3adcfa4478 l2tp: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the
return value.  The function can work or not, but the code logic should
never do something different based on this.

Also, there is no need to store the individual debugfs file name, just
remove the whole directory all at once, saving a local variable.

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guillaume Nault <g.nault@alphalink.fr>
Cc: netdev@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14 08:45:05 -07:00
Thomas Gleixner
2874c5fd28 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 3029 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070032.746973796@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:32 -07:00
Thomas Gleixner
ec8f24b7fa treewide: Add SPDX license identifier - Makefile/Kconfig
Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 10:50:46 +02:00
David S. Miller
a9e41a5296 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Minor conflict with the DSA legacy code removal.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-07 17:22:09 -07:00
YueHaibing
638a3a1e34 l2tp: Fix possible NULL pointer dereference
BUG: unable to handle kernel NULL pointer dereference at 0000000000000128
PGD 0 P4D 0
Oops: 0000 [#1
CPU: 0 PID: 5697 Comm: modprobe Tainted: G        W         5.1.0-rc7+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
RIP: 0010:__lock_acquire+0x53/0x10b0
Code: 8b 1c 25 40 5e 01 00 4c 8b 6d 10 45 85 e4 0f 84 bd 06 00 00 44 8b 1d 7c d2 09 02 49 89 fe 41 89 d2 45 85 db 0f 84 47 02 00 00 <48> 81 3f a0 05 70 83 b8 00 00 00 00 44 0f 44 c0 83 fe 01 0f 86 3a
RSP: 0018:ffffc90001c07a28 EFLAGS: 00010002
RAX: 0000000000000000 RBX: ffff88822f038440 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000128
RBP: ffffc90001c07a88 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000128 R15: 0000000000000000
FS:  00007fead0811540(0000) GS:ffff888237a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000128 CR3: 00000002310da000 CR4: 00000000000006f0
Call Trace:
 ? __lock_acquire+0x24e/0x10b0
 lock_acquire+0xdf/0x230
 ? flush_workqueue+0x71/0x530
 flush_workqueue+0x97/0x530
 ? flush_workqueue+0x71/0x530
 l2tp_exit_net+0x170/0x2b0 [l2tp_core
 ? l2tp_exit_net+0x93/0x2b0 [l2tp_core
 ops_exit_list.isra.6+0x36/0x60
 unregister_pernet_operations+0xb8/0x110
 unregister_pernet_device+0x25/0x40
 l2tp_init+0x55/0x1000 [l2tp_core
 ? 0xffffffffa018d000
 do_one_initcall+0x6c/0x3cc
 ? do_init_module+0x22/0x1f1
 ? rcu_read_lock_sched_held+0x97/0xb0
 ? kmem_cache_alloc_trace+0x325/0x3b0
 do_init_module+0x5b/0x1f1
 load_module+0x1db1/0x2690
 ? m_show+0x1d0/0x1d0
 __do_sys_finit_module+0xc5/0xd0
 __x64_sys_finit_module+0x15/0x20
 do_syscall_64+0x6b/0x1d0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fead031a839
Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48
RSP: 002b:00007ffe8d9acca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
RAX: ffffffffffffffda RBX: 0000560078398b80 RCX: 00007fead031a839
RDX: 0000000000000000 RSI: 000056007659dc2e RDI: 0000000000000003
RBP: 000056007659dc2e R08: 0000000000000000 R09: 0000560078398b80
R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
R13: 00005600783a04a0 R14: 0000000000040000 R15: 0000560078398b80
Modules linked in: l2tp_core(+) e1000 ip_tables ipv6 [last unloaded: l2tp_core
CR2: 0000000000000128
---[ end trace 8322b2b8bf83f8e1

If alloc_workqueue fails in l2tp_init, l2tp_net_ops
is unregistered on failure path. Then l2tp_exit_net
is called which will flush NULL workqueue, this patch
add a NULL check to fix it.

Fixes: 67e04c29ec ("l2tp: unregister l2tp_net_ops on failure path")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-07 12:16:47 -07:00
David S. Miller
ff24e4980a Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Three trivial overlapping conflicts.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-02 22:14:21 -04:00
Eric Dumazet
a622b40035 l2ip: fix possible use-after-free
Before taking a refcount on a rcu protected structure,
we need to make sure the refcount is not zero.

syzbot reported :

refcount_t: increment on 0; use-after-free.
WARNING: CPU: 1 PID: 23533 at lib/refcount.c:156 refcount_inc_checked lib/refcount.c:156 [inline]
WARNING: CPU: 1 PID: 23533 at lib/refcount.c:156 refcount_inc_checked+0x61/0x70 lib/refcount.c:154
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 23533 Comm: syz-executor.2 Not tainted 5.1.0-rc7+ #93
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 panic+0x2cb/0x65c kernel/panic.c:214
 __warn.cold+0x20/0x45 kernel/panic.c:571
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:refcount_inc_checked lib/refcount.c:156 [inline]
RIP: 0010:refcount_inc_checked+0x61/0x70 lib/refcount.c:154
Code: 1d 98 2b 2a 06 31 ff 89 de e8 db 2c 40 fe 84 db 75 dd e8 92 2b 40 fe 48 c7 c7 20 7a a1 87 c6 05 78 2b 2a 06 01 e8 7d d9 12 fe <0f> 0b eb c1 90 90 90 90 90 90 90 90 90 90 90 55 48 89 e5 41 57 41
RSP: 0018:ffff888069f0fba8 EFLAGS: 00010286
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000f353 RSI: ffffffff815afcb6 RDI: ffffed100d3e1f67
RBP: ffff888069f0fbb8 R08: ffff88809b1845c0 R09: ffffed1015d23ef1
R10: ffffed1015d23ef0 R11: ffff8880ae91f787 R12: ffff8880a8f26968
R13: 0000000000000004 R14: dffffc0000000000 R15: ffff8880a49a6440
 l2tp_tunnel_inc_refcount net/l2tp/l2tp_core.h:240 [inline]
 l2tp_tunnel_get+0x250/0x580 net/l2tp/l2tp_core.c:173
 pppol2tp_connect+0xc00/0x1c70 net/l2tp/l2tp_ppp.c:702
 __sys_connect+0x266/0x330 net/socket.c:1808
 __do_sys_connect net/socket.c:1819 [inline]
 __se_sys_connect net/socket.c:1816 [inline]
 __x64_sys_connect+0x73/0xb0 net/socket.c:1816

Fixes: 54652eb12c ("l2tp: hold tunnel while looking up sessions in l2tp_netlink")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Cc: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-30 11:35:48 -04:00
Johannes Berg
ef6243acb4 genetlink: optionally validate strictly/dumps
Add options to strictly validate messages and dump messages,
sometimes perhaps validating dump messages non-strictly may
be required, so add an option for that as well.

Since none of this can really be applied to existing commands,
set the options everwhere using the following spatch:

    @@
    identifier ops;
    expression X;
    @@
    struct genl_ops ops[] = {
    ...,
     {
            .cmd = X,
    +       .validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
            ...
     },
    ...
    };

For new commands one should just not copy the .validate 'opt-out'
flags and thus get strict validation.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27 17:07:22 -04:00
Michal Kubecek
ae0be8de9a netlink: make nla_nest_start() add NLA_F_NESTED flag
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most
netlink based interfaces (including recently added ones) are still not
setting it in kernel generated messages. Without the flag, message parsers
not aware of attribute semantics (e.g. wireshark dissector or libmnl's
mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display
the structure of their contents.

Unfortunately we cannot just add the flag everywhere as there may be
userspace applications which check nlattr::nla_type directly rather than
through a helper masking out the flags. Therefore the patch renames
nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start()
as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually
are rewritten to use nla_nest_start().

Except for changes in include/net/netlink.h, the patch was generated using
this semantic patch:

@@ expression E1, E2; @@
-nla_nest_start(E1, E2)
+nla_nest_start_noflag(E1, E2)

@@ expression E1, E2; @@
-nla_nest_start_noflag(E1, E2 | NLA_F_NESTED)
+nla_nest_start(E1, E2)

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-27 17:03:44 -04:00
Eric Dumazet
c1c4772178 l2tp: use rcu_dereference_sk_user_data() in l2tp_udp_encap_recv()
Canonical way to fetch sk_user_data from an encap_rcv() handler called
from UDP stack in rcu protected section is to use rcu_dereference_sk_user_data(),
otherwise compiler might read it multiple times.

Fixes: d00fa9adc5 ("il2tp: fix races with tunnel socket close")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Chapman <jchapman@katalix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-26 11:18:23 -04:00
Arnd Bergmann
c7cbdbf29f net: rework SIOCGSTAMP ioctl handling
The SIOCGSTAMP/SIOCGSTAMPNS ioctl commands are implemented by many
socket protocol handlers, and all of those end up calling the same
sock_get_timestamp()/sock_get_timestampns() helper functions, which
results in a lot of duplicate code.

With the introduction of 64-bit time_t on 32-bit architectures, this
gets worse, as we then need four different ioctl commands in each
socket protocol implementation.

To simplify that, let's add a new .gettstamp() operation in
struct proto_ops, and move ioctl implementation into the common
sock_ioctl()/compat_sock_ioctl_trans() functions that these all go
through.

We can reuse the sock_get_timestamp() implementation, but generalize
it so it can deal with both native and compat mode, as well as
timeval and timespec structures.

Acked-by: Stefan Schmidt <stefan@datenfreihafen.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://lore.kernel.org/lkml/CAK8P3a038aDQQotzua_QtKGhq8O9n+rdiz2=WDCp82ys8eUT+A@mail.gmail.com/
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-19 14:07:40 -07:00
Jakub Kicinski
503c018801 l2tp: fix set but not used variable
GCC complains:

net/l2tp/l2tp_ppp.c: In function ‘pppol2tp_ioctl’:
net/l2tp/l2tp_ppp.c:1073:6: warning: variable ‘val’ set but not used [-Wunused-but-set-variable]
  int val;
      ^~~

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-04-18 17:06:15 -07:00
Johannes Berg
3b0f31f2b8 genetlink: make policy common to family
Since maxattr is common, the policy can't really differ sanely,
so make it common as well.

The only user that did in fact manage to make a non-common policy
is taskstats, which has to be really careful about it (since it's
still using a common maxattr!). This is no longer supported, but
we can fake it using pre_doit.

This reduces the size of e.g. nl80211.o (which has lots of commands):

   text	   data	    bss	    dec	    hex	filename
 398745	  14323	   2240	 415308	  6564c	net/wireless/nl80211.o (before)
 397913	  14331	   2240	 414484	  65314	net/wireless/nl80211.o (after)
--------------------------------
   -832      +8       0    -824

Which is obviously just 8 bytes for each command, and an added 8
bytes for the new policy pointer. I'm not sure why the ops list is
counted as .text though.

Most of the code transformations were done using the following spatch:
    @ops@
    identifier OPS;
    expression POLICY;
    @@
    struct genl_ops OPS[] = {
    ...,
     {
    -	.policy = POLICY,
     },
    ...
    };

    @@
    identifier ops.OPS;
    expression ops.POLICY;
    identifier fam;
    expression M;
    @@
    struct genl_family fam = {
            .ops = OPS,
            .maxattr = M,
    +       .policy = POLICY,
            ...
    };

This also gets rid of devlink_nl_cmd_region_read_dumpit() accessing
the cb->data as ops, which we want to change in a later genl patch.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-22 10:38:23 -04:00
Eric Dumazet
163d1c3d6f l2tp: fix infoleak in l2tp_ip6_recvmsg()
Back in 2013 Hannes took care of most of such leaks in commit
bceaa90240 ("inet: prevent leakage of uninitialized memory to user in recv syscalls")

But the bug in l2tp_ip6_recvmsg() has not been fixed.

syzbot report :

BUG: KMSAN: kernel-infoleak in _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32
CPU: 1 PID: 10996 Comm: syz-executor362 Not tainted 5.0.0+ #11
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x173/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x12e/0x2a0 mm/kmsan/kmsan.c:600
 kmsan_internal_check_memory+0x9f4/0xb10 mm/kmsan/kmsan.c:694
 kmsan_copy_to_user+0xab/0xc0 mm/kmsan/kmsan_hooks.c:601
 _copy_to_user+0x16b/0x1f0 lib/usercopy.c:32
 copy_to_user include/linux/uaccess.h:174 [inline]
 move_addr_to_user+0x311/0x570 net/socket.c:227
 ___sys_recvmsg+0xb65/0x1310 net/socket.c:2283
 do_recvmmsg+0x646/0x10c0 net/socket.c:2390
 __sys_recvmmsg net/socket.c:2469 [inline]
 __do_sys_recvmmsg net/socket.c:2492 [inline]
 __se_sys_recvmmsg+0x1d1/0x350 net/socket.c:2485
 __x64_sys_recvmmsg+0x62/0x80 net/socket.c:2485
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x445819
Code: e8 6c b6 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b 12 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f64453eddb8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00000000006dac28 RCX: 0000000000445819
RDX: 0000000000000005 RSI: 0000000020002f80 RDI: 0000000000000003
RBP: 00000000006dac20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dac2c
R13: 00007ffeba8f87af R14: 00007f64453ee9c0 R15: 20c49ba5e353f7cf

Local variable description: ----addr@___sys_recvmsg
Variable was created at:
 ___sys_recvmsg+0xf6/0x1310 net/socket.c:2244
 do_recvmmsg+0x646/0x10c0 net/socket.c:2390

Bytes 0-31 of 32 are uninitialized
Memory access of size 32 starts at ffff8880ae62fbb0
Data copied to user address 0000000020000000

Fixes: a32e0eec70 ("l2tp: introduce L2TPv3 IP encapsulation support for IPv6")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-03-13 14:19:35 -07:00
Jacob Wen
91c524708d l2tp: copy 4 more bytes to linear part if necessary
The size of L2TPv2 header with all optional fields is 14 bytes.
l2tp_udp_recv_core only moves 10 bytes to the linear part of a
skb. This may lead to l2tp_recv_common read data outside of a skb.

This patch make sure that there is at least 14 bytes in the linear
part of a skb to meet the maximum need of l2tp_udp_recv_core and
l2tp_recv_common. The minimum size of both PPP HDLC-like frame and
Ethernet frame is larger than 14 bytes, so we are safe to do so.

Also remove L2TP_HDR_SIZE_NOSEQ, it is unused now.

Fixes: fd558d186d ("l2tp: Split pppol2tp patch into separate l2tp and ppp parts")
Suggested-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Jacob Wen <jian.w.wen@oracle.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-31 08:58:46 -08:00
Jacob Wen
4522a70db7 l2tp: fix reading optional fields of L2TPv3
Use pskb_may_pull() to make sure the optional fields are in skb linear
parts, so we can safely read them later.

It's easy to reproduce the issue with a net driver that supports paged
skb data. Just create a L2TPv3 over IP tunnel and then generates some
network traffic.
Once reproduced, rx err in /sys/kernel/debug/l2tp/tunnels will increase.

Changes in v4:
1. s/l2tp_v3_pull_opt/l2tp_v3_ensure_opt_in_linear/
2. s/tunnel->version != L2TP_HDR_VER_2/tunnel->version == L2TP_HDR_VER_3/
3. Add 'Fixes' in commit messages.

Changes in v3:
1. To keep consistency, move the code out of l2tp_recv_common.
2. Use "net" instead of "net-next", since this is a bug fix.

Changes in v2:
1. Only fix L2TPv3 to make code simple.
   To fix both L2TPv3 and L2TPv2, we'd better refactor l2tp_recv_common.
   It's complicated to do so.
2. Reloading pointers after pskb_may_pull

Fixes: f7faffa3ff ("l2tp: Add L2TPv3 protocol support")
Fixes: 0d76751fad ("l2tp: Add L2TPv3 IP encapsulation (no UDP) support")
Fixes: a32e0eec70 ("l2tp: introduce L2TPv3 IP encapsulation support for IPv6")
Signed-off-by: Jacob Wen <jian.w.wen@oracle.com>
Acked-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-30 21:44:17 -08:00
Xin Long
f8504f4ca0 l2tp: fix a sock refcnt leak in l2tp_tunnel_register
This issue happens when trying to add an existent tunnel. It
doesn't call sock_put() before returning -EEXIST to release
the sock refcnt that was held by calling sock_hold() before
the existence check.

This patch is to fix it by holding the sock after doing the
existence check.

Fixes: f6cd651b05 ("l2tp: fix race in duplicate tunnel detection")
Reported-by: Jianlin Shi <jishi@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-11-14 22:49:31 -08:00
Arnd Bergmann
c2ebc25674 l2tp: fix unused function warning
Removing one of the callers of pppol2tp_session_get_sock caused a harmless
warning in some configurations:

net/l2tp/l2tp_ppp.c:142:21: 'pppol2tp_session_get_sock' defined but not used [-Wunused-function]

Rather than adding another #ifdef here, using a proper IS_ENABLED()
check makes the code more readable and avoids those warnings while
letting the compiler figure out for itself which code is needed.

This adds one pointer for the unused show() callback in struct
l2tp_session, but that seems harmless.

Fixes: b0e29063dc ("l2tp: remove pppol2tp_session_ioctl()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-13 20:45:49 -07:00
Wei Wang
6d37fa49da l2tp: use sk_dst_check() to avoid race on sk->sk_dst_cache
In l2tp code, if it is a L2TP_UDP_ENCAP tunnel, tunnel->sk points to a
UDP socket. User could call sendmsg() on both this tunnel and the UDP
socket itself concurrently. As l2tp_xmit_skb() holds socket lock and call
__sk_dst_check() to refresh sk->sk_dst_cache, while udpv6_sendmsg() is
lockless and call sk_dst_check() to refresh sk->sk_dst_cache, there
could be a race and cause the dst cache to be freed multiple times.
So we fix l2tp side code to always call sk_dst_check() to garantee
xchg() is called when refreshing sk->sk_dst_cache to avoid race
conditions.

Syzkaller reported stack trace:
BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: use-after-free in atomic_fetch_add_unless include/linux/atomic.h:575 [inline]
BUG: KASAN: use-after-free in atomic_add_unless include/linux/atomic.h:597 [inline]
BUG: KASAN: use-after-free in dst_hold_safe include/net/dst.h:308 [inline]
BUG: KASAN: use-after-free in ip6_hold_safe+0xe6/0x670 net/ipv6/route.c:1029
Read of size 4 at addr ffff8801aea9a880 by task syz-executor129/4829

CPU: 0 PID: 4829 Comm: syz-executor129 Not tainted 4.18.0-rc7-next-20180802+ #30
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x30d mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
 atomic_fetch_add_unless include/linux/atomic.h:575 [inline]
 atomic_add_unless include/linux/atomic.h:597 [inline]
 dst_hold_safe include/net/dst.h:308 [inline]
 ip6_hold_safe+0xe6/0x670 net/ipv6/route.c:1029
 rt6_get_pcpu_route net/ipv6/route.c:1249 [inline]
 ip6_pol_route+0x354/0xd20 net/ipv6/route.c:1922
 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2098
 fib6_rule_lookup+0x283/0x890 net/ipv6/fib6_rules.c:122
 ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:2126
 ip6_dst_lookup_tail+0x1278/0x1da0 net/ipv6/ip6_output.c:978
 ip6_dst_lookup_flow+0xc8/0x270 net/ipv6/ip6_output.c:1079
 ip6_sk_dst_lookup_flow+0x5ed/0xc50 net/ipv6/ip6_output.c:1117
 udpv6_sendmsg+0x2163/0x36b0 net/ipv6/udp.c:1354
 inet_sendmsg+0x1a1/0x690 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:632
 ___sys_sendmsg+0x51d/0x930 net/socket.c:2115
 __sys_sendmmsg+0x240/0x6f0 net/socket.c:2210
 __do_sys_sendmmsg net/socket.c:2239 [inline]
 __se_sys_sendmmsg net/socket.c:2236 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2236
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446a29
Code: e8 ac b8 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f4de5532db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 0000000000446a29
RDX: 00000000000000b8 RSI: 0000000020001b00 RDI: 0000000000000003
RBP: 00000000006dcc30 R08: 00007f4de5533700 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c
R13: 00007ffe2b830fdf R14: 00007f4de55339c0 R15: 0000000000000001

Fixes: 71b1391a41 ("l2tp: ensure sk->dst is still valid")
Reported-by: syzbot+05f840f3b04f211bad55@syzkaller.appspotmail.com
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Cc: Guillaume Nault <g.nault@alphalink.fr>
Cc: David Ahern <dsahern@gmail.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-13 08:43:36 -07:00
Guillaume Nault
4f5f85e9a7 l2tp: let pppol2tp_ioctl() fallback to dev_ioctl()
Return -ENOIOCTLCMD for unknown ioctl commands. This lets dev_ioctl()
handle generic socket ioctls like SIOCGIFNAME or SIOCGIFINDEX.
PF_PPPOX/PX_PROTO_OL2TP was one of the few socket types not honouring
this mechanism.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 12:13:49 -07:00
Guillaume Nault
7390ed8a40 l2tp: zero out stats in pppol2tp_copy_stats()
Integrate memset(0) in pppol2tp_copy_stats() to avoid calling it
manually every time.

While there, constify 'stats'.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 12:13:49 -07:00
Guillaume Nault
b0e29063dc l2tp: remove pppol2tp_session_ioctl()
pppol2tp_ioctl() has everything in place for handling PPPIOCGL2TPSTATS
on session sockets. We just need to copy the stats and set ->session_id.

As a side effect of sharing session and tunnel code, ->using_ipsec is
properly set even when the request was made using a session socket.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 12:13:49 -07:00
Guillaume Nault
528534f0de l2tp: remove pppol2tp_tunnel_ioctl()
Handle PPPIOCGL2TPSTATS in pppol2tp_ioctl() if the socket represents a
tunnel. This one is a bit special because the caller may use the tunnel
socket to retrieve statistics of one of its sessions. If the session_id
is set, the corresponding session's statistics are returned, instead of
those of the tunnel. This is handled by the new
pppol2tp_tunnel_copy_stats() helper function.

Set ->tunnel_id and ->using_ipsec out of the conditional, so
that it can be used by the 'else' branch in the following patch.
We cannot do that for ->session_id, because tunnel sockets have to
report the value that was originally passed in 'stats.session_id',
while session sockets have to report their own session_id.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 12:13:49 -07:00
Guillaume Nault
79e6760e64 l2tp: handle PPPIOC[GS]MRU and PPPIOC[GS]FLAGS in pppol2tp_ioctl()
Let pppol2tp_ioctl() handle ioctl commands directly. It still relies on
pppol2tp_{session,tunnel}_ioctl() for PPPIOCGL2TPSTATS.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 12:13:49 -07:00
Guillaume Nault
bdd0292f96 l2tp: simplify pppol2tp_ioctl()
* Drop test on 'sk': sock->sk cannot be NULL, or pppox_ioctl() could
    not have called us.

  * Drop test on 'SOCK_DEAD' state: if this flag was set, the socket
    would be in the process of being released and no ioctl could be
    running anymore.

  * Drop test on 'PPPOX_*' state: we depend on ->sk_user_data to get
    the session structure. If it is non-NULL, then the socket is
    connected. Testing for PPPOX_* is redundant.

  * Retrieve session using ->sk_user_data directly, instead of going
    through pppol2tp_sock_to_session(). This avoids grabbing a useless
    reference on the socket.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 12:13:49 -07:00
Guillaume Nault
01e28b921b l2tp: split l2tp_session_get()
l2tp_session_get() is used for two different purposes. If 'tunnel' is
NULL, the session is searched globally in the supplied network
namespace. Otherwise it is searched exclusively in the tunnel context.

Callers always know the context in which they need to search the
session. But some of them do provide both a namespace and a tunnel,
making the semantic of the call unclear.

This patch defines l2tp_tunnel_get_session() for lookups done in a
tunnel and restricts l2tp_session_get() to namespace searches.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 12:13:49 -07:00
Guillaume Nault
d6a61ec936 l2tp: define l2tp_tunnel_uses_xfrm()
Use helper function to figure out if a tunnel is using ipsec.
Also, avoid accessing ->sk_policy directly since it's RCU protected.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-11 12:13:49 -07:00
David S. Miller
c1c8626fce Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net
Lots of overlapping changes, mostly trivial in nature.

The mlxsw conflict was resolving using the example
resolution at:

https://github.com/jpirko/linux_mlxsw/blob/combined_queue/drivers/net/ethernet/mellanox/mlxsw/core_acl_flex_actions.c

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-05 13:04:31 -07:00
Guillaume Nault
f664e37dcc l2tp: fix missing refcount drop in pppol2tp_tunnel_ioctl()
If 'session' is not NULL and is not a PPP pseudo-wire, then we fail to
drop the reference taken by l2tp_session_get().

Fixes: ecd012e45a ("l2tp: filter out non-PPP sessions in pppol2tp_tunnel_ioctl()")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03 12:39:01 -07:00
Guillaume Nault
e9697e2eff l2tp: ignore L2TP_ATTR_MTU
This attribute's handling is broken. It can only be used when creating
Ethernet pseudo-wires, in which case its value can be used as the
initial MTU for the l2tpeth device.
However, when handling update requests, L2TP_ATTR_MTU only modifies
session->mtu. This value is never propagated to the l2tpeth device.
Dump requests also return the value of session->mtu, which is not
synchronised anymore with the device MTU.

The same problem occurs if the device MTU is properly updated using the
generic IFLA_MTU attribute. In this case, session->mtu is not updated,
and L2TP_ATTR_MTU will report an invalid value again when dumping the
session.

It does not seem worthwhile to complexify l2tp_eth.c to synchronise
session->mtu with the device MTU. Even the ip-l2tp manpage advises to
use 'ip link' to initialise the MTU of l2tpeth devices (iproute2 does
not handle L2TP_ATTR_MTU at all anyway). So let's just ignore it
entirely.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03 10:03:57 -07:00
Guillaume Nault
789141b215 l2tp: simplify MTU handling in l2tp_ppp
The value of the session's .mtu field, as defined by
pppol2tp_connect() or pppol2tp_session_create(), is later overwritten
by pppol2tp_session_init() (unless getting the tunnel's socket PMTU
fails). This field is then only used when setting the PPP channel's MTU
in pppol2tp_connect().
Furthermore, the SIOC[GS]IFMTU ioctls only act on the session's .mtu
without propagating this value to the PPP channel, making them useless.

This patch initialises the PPP channel's MTU directly and ignores the
session's .mtu entirely. MTU is still computed by subtracting the
PPPOL2TP_HEADER_OVERHEAD constant. It is not optimal, but that doesn't
really matter: po->chan.mtu is only used when the channel is part of a
multilink PPP bundle. Running multilink PPP over packet switched
networks is certainly not going to be efficient, so not picking the
best MTU does not harm (in the worst case, packets will just be
fragmented by the underlay).

The SIOC[GS]IFMTU ioctls are removed entirely (as opposed to simply
ignored), because these ioctls commands are part of the requests that
should be handled generically by the socket layer. PX_PROTO_OL2TP was
the only socket type abusing these ioctls.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03 10:03:57 -07:00
Guillaume Nault
1f5cd2a010 l2tp: define l2tp_tunnel_dst_mtu()
Consolidate retrieval of tunnel's socket mtu in order to simplify
l2tp_eth and l2tp_ppp a bit.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-03 10:03:57 -07:00
Guillaume Nault
92ea4a7eec l2tp: drop ->mru from struct l2tp_session
This field is not used.

Treat PPPIOC*MRU the same way as PPPIOC*FLAGS: "get" requests return 0,
while "set" requests vadidate the user supplied pointer but discard its
value.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27 13:34:53 -07:00
Guillaume Nault
1998b5ed9c l2tp: drop ->flags from struct pppol2tp_session
This field is not used.

Keep validating user input in PPPIOCSFLAGS. Even though we discard the
value, it would look wrong to succeed if an invalid address was passed
from userspace.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27 13:34:53 -07:00
Guillaume Nault
ae51a7c6d5 l2tp: ignore L2TP_ATTR_VLAN_ID netlink attribute
The value of this attribute is never used.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27 13:34:53 -07:00
Guillaume Nault
3ae5536b80 l2tp: ignore L2TP_ATTR_DATA_SEQ netlink attribute
The value of this attribute is never used.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-27 13:34:53 -07:00
Guillaume Nault
2b139e6b1e l2tp: remove ->recv_payload_hook
The tunnel reception hook is only used by l2tp_ppp for skipping PPP
framing bytes. This is a session specific operation, but once a PPP
session sets ->recv_payload_hook on its tunnel, all frames received by
the tunnel will enter pppol2tp_recv_payload_hook(), including those
targeted at Ethernet sessions (an L2TPv3 tunnel can multiplex PPP and
Ethernet sessions).

So this mechanism is wrong, and uselessly complex. Let's just move this
functionality to the pppol2tp rx handler and drop ->recv_payload_hook.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-26 14:06:34 -07:00
Stephen Hemminger
c2df560367 l2tp: remove trailing newline
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-24 14:10:43 -07:00
Willem de Bruijn
5fdaa88dfe ipv6: fold sockcm_cookie into ipcm6_cookie
ipcm_cookie includes sockcm_cookie. Do the same for ipcm6_cookie.

This reduces the number of arguments that need to be passed around,
applies ipcm6_init to all cookie fields at once and reduces code
differentiation between ipv4 and ipv6.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-07 10:58:49 +09:00
Willem de Bruijn
b515430ac9 ipv6: ipcm6_cookie initializer
Initialize the cookie in one location to reduce code duplication and
avoid bugs from inconsistent initialization, such as that fixed in
commit 9887cba199 ("ip: limit use of gso_size to udp").

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-07 10:58:49 +09:00
David S. Miller
5cd3da4ba2 Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/net
Simple overlapping changes in stmmac driver.

Adjust skb_gro_flush_final_remcsum function signature to make GRO list
changes in net-next, as per Stephen Rothwell's example merge
resolution.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-07-03 10:29:26 +09:00
Linus Torvalds
a11e1d432b Revert changes to convert to ->poll_mask() and aio IOCB_CMD_POLL
The poll() changes were not well thought out, and completely
unexplained.  They also caused a huge performance regression, because
"->poll()" was no longer a trivial file operation that just called down
to the underlying file operations, but instead did at least two indirect
calls.

Indirect calls are sadly slow now with the Spectre mitigation, but the
performance problem could at least be largely mitigated by changing the
"->get_poll_head()" operation to just have a per-file-descriptor pointer
to the poll head instead.  That gets rid of one of the new indirections.

But that doesn't fix the new complexity that is completely unwarranted
for the regular case.  The (undocumented) reason for the poll() changes
was some alleged AIO poll race fixing, but we don't make the common case
slower and more complex for some uncommon special case, so this all
really needs way more explanations and most likely a fundamental
redesign.

[ This revert is a revert of about 30 different commits, not reverted
  individually because that would just be unnecessarily messy  - Linus ]

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-28 10:40:47 -07:00
Guillaume Nault
a408194aa0 l2tp: define helper for parsing struct sockaddr_pppol2tp*
'sockaddr_len' is checked against various values when entering
pppol2tp_connect(), to verify its validity. It is used again later, to
find out which sockaddr structure was passed from user space. This
patch combines these two operations into one new function in order to
simplify pppol2tp_connect().

A new structure, l2tp_connect_info, is used to pass sockaddr data back
to pppol2tp_connect(), to avoid passing too many parameters to
l2tp_sockaddr_get_info(). Also, the first parameter is void* in order
to avoid casting between all sockaddr_* structures manually.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-28 16:06:50 +09:00
Guillaume Nault
2685fbb804 l2tp: make l2tp_xmit_core() return void
It always returns 0, and nobody reads the return value anyway.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26 22:55:51 +09:00
Guillaume Nault
363a341d19 l2tp: avoid duplicate l2tp_pernet() calls
Replace 'l2tp_pernet(tunnel->l2tp_net)' with 'pn', which has been set
on the preceding line.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-26 22:55:51 +09:00