Commit Graph

5937 Commits

Author SHA1 Message Date
Paolo Abeni
e94e50bd88 net: fix possible user-after-free in skb_ext_add()
On cow we can free the old extension: we must avoid dereferencing
such extension after skb_ext_maybe_cow(). Since 'new' contents
are always equal to 'old' after the copy, we can fix the above
accessing the relevant data using 'new'.

Fixes: df5042f4c5 ("sk_buff: add skb extension infrastructure")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-21 10:24:54 -08:00
David S. Miller
339bbff2d6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-12-21

The following pull-request contains BPF updates for your *net-next* tree.

There is a merge conflict in test_verifier.c. Result looks as follows:

        [...]
        },
        {
                "calls: cross frame pruning",
                .insns = {
                [...]
                .prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
                .errstr_unpriv = "function calls to other bpf functions are allowed for root only",
                .result_unpriv = REJECT,
                .errstr = "!read_ok",
                .result = REJECT,
	},
        {
                "jset: functional",
                .insns = {
        [...]
        {
                "jset: unknown const compare not taken",
                .insns = {
                        BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0,
                                     BPF_FUNC_get_prandom_u32),
                        BPF_JMP_IMM(BPF_JSET, BPF_REG_0, 1, 1),
                        BPF_LDX_MEM(BPF_B, BPF_REG_8, BPF_REG_9, 0),
                        BPF_EXIT_INSN(),
                },
                .prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
                .errstr_unpriv = "!read_ok",
                .result_unpriv = REJECT,
                .errstr = "!read_ok",
                .result = REJECT,
        },
        [...]
        {
                "jset: range",
                .insns = {
                [...]
                },
                .prog_type = BPF_PROG_TYPE_SOCKET_FILTER,
                .result_unpriv = ACCEPT,
                .result = ACCEPT,
        },

The main changes are:

1) Various BTF related improvements in order to get line info
   working. Meaning, verifier will now annotate the corresponding
   BPF C code to the error log, from Martin and Yonghong.

2) Implement support for raw BPF tracepoints in modules, from Matt.

3) Add several improvements to verifier state logic, namely speeding
   up stacksafe check, optimizations for stack state equivalence
   test and safety checks for liveness analysis, from Alexei.

4) Teach verifier to make use of BPF_JSET instruction, add several
   test cases to kselftests and remove nfp specific JSET optimization
   now that verifier has awareness, from Jakub.

5) Improve BPF verifier's slot_type marking logic in order to
   allow more stack slot sharing, from Jiong.

6) Add sk_msg->size member for context access and add set of fixes
   and improvements to make sock_map with kTLS usable with openssl
   based applications, from John.

7) Several cleanups and documentation updates in bpftool as well as
   auto-mount of tracefs for "bpftool prog tracelog" command,
   from Quentin.

8) Include sub-program tags from now on in bpf_prog_info in order to
   have a reliable way for user space to get all tags of the program
   e.g. needed for kallsyms correlation, from Song.

9) Add BTF annotations for cgroup_local_storage BPF maps and
   implement bpf fs pretty print support, from Roman.

10) Fix bpftool in order to allow for cross-compilation, from Ivan.

11) Update of bpftool license to GPLv2-only + BSD-2-Clause in order
    to be compatible with libbfd and allow for Debian packaging,
    from Jakub.

12) Remove an obsolete prog->aux sanitation in dump and get rid of
    version check for prog load, from Daniel.

13) Fix a memory leak in libbpf's line info handling, from Prashant.

14) Fix cpumap's frame alignment for build_skb() so that skb_shared_info
    does not get unaligned, from Jesper.

15) Fix test_progs kselftest to work with older compilers which are less
    smart in optimizing (and thus throwing build error), from Stanislav.

16) Cleanup and simplify AF_XDP socket teardown, from Björn.

17) Fix sk lookup in BPF kselftest's test_sock_addr with regards
    to netns_id argument, from Andrey.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-20 17:31:36 -08:00
Colin Ian King
463561e6b9 neighbour: remove stray semicolon
Currently the stray semicolon means that the final term in the addition
is being missed.  Fix this by removing it. Cleans up clang warning:

net/core/neighbour.c:2821:9: warning: expression result unused [-Wunused-value]

Fixes: 82cbb5c631 ("neighbour: register rtnl doit handler")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-By: Roopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-20 16:36:28 -08:00
John Fastabend
a136678c0b bpf: sk_msg, zap ingress queue on psock down
In addition to releasing any cork'ed data on a psock when the psock
is removed we should also release any skb's in the ingress work queue.
Otherwise the skb's eventually get free'd but late in the tear
down process so we see the WARNING due to non-zero sk_forward_alloc.

  void sk_stream_kill_queues(struct sock *sk)
  {
	...
	WARN_ON(sk->sk_forward_alloc);
	...
  }

Fixes: 604326b41a ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-20 23:47:09 +01:00
John Fastabend
552de91068 bpf: sk_msg, fix socket data_ready events
When a skb verdict program is in-use and either another BPF program
redirects to that socket or the new SK_PASS support is used the
data_ready callback does not wake up application. Instead because
the stream parser/verdict is using the sk data_ready callback we wake
up the stream parser/verdict block.

Fix this by adding a helper to check if the stream parser block is
enabled on the sk and if so call the saved pointer which is the
upper layers wake up function.

This fixes application stalls observed when an application is waiting
for data in a blocking read().

Fixes: d829e9c411 ("tls: convert to generic sk_msg interface")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-20 23:47:09 +01:00
John Fastabend
51199405f9 bpf: skb_verdict, support SK_PASS on RX BPF path
Add SK_PASS verdict support to SK_SKB_VERDICT programs. Now that
support for redirects exists we can implement SK_PASS as a redirect
to the same socket. This simplifies the BPF programs and avoids an
extra map lookup on RX path for simple visibility cases.

Further, reduces user (BPF programmer in this context) confusion
when their program drops skb due to lack of support.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-20 23:47:09 +01:00
John Fastabend
7a69c0f250 bpf: skmsg, replace comments with BUILD bug
Enforce comment on structure layout dependency with a BUILD_BUG_ON
to ensure the condition is maintained.

Suggested-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-20 23:47:09 +01:00
John Fastabend
bc1b4f013b bpf: sk_msg, improve offset chk in _is_valid_access
The check for max offset in sk_msg_is_valid_access uses sizeof()
which is incorrect because it would allow accessing possibly
past the end of the struct in the padded case. Further, it doesn't
preclude accessing any padding that may be added in the middle of
a struct. All told this makes it fragile to rely on.

To fix this explicitly check offsets with fields using the
bpf_ctx_range() and bpf_ctx_range_till() macros.

For reference the current structure layout looks as follows (reported
by pahole)

struct sk_msg_md {
	union {
		void *             data;                 /*           8 */
	};                                               /*     0     8 */
	union {
		void *             data_end;             /*           8 */
	};                                               /*     8     8 */
	__u32                      family;               /*    16     4 */
	__u32                      remote_ip4;           /*    20     4 */
	__u32                      local_ip4;            /*    24     4 */
	__u32                      remote_ip6[4];        /*    28    16 */
	__u32                      local_ip6[4];         /*    44    16 */
	__u32                      remote_port;          /*    60     4 */
	/* --- cacheline 1 boundary (64 bytes) --- */
	__u32                      local_port;           /*    64     4 */
	__u32                      size;                 /*    68     4 */

	/* size: 72, cachelines: 2, members: 10 */
	/* last cacheline: 8 bytes */
};

So there should be no padding at the moment but fixing this now
prevents future errors.

Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-20 23:47:08 +01:00
David S. Miller
2be09de7d6 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Lots of conflicts, by happily all cases of overlapping
changes, parallel adds, things of that nature.

Thanks to Stephen Rothwell, Saeed Mahameed, and others
for their guidance in these resolutions.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-20 11:53:36 -08:00
David Ahern
a9cd3439e3 neighbor: Use nda_policy for validating attributes in adds and dump requests
Add NDA_PROTOCOL to nda_policy and use the policy for attribute parsing and
validation for adding neighbors and in dump requests. Remove the now duplicate
checks on nla_len.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 23:55:36 -08:00
David Ahern
c0fde870d9 neighbor: NTF_PROXY is a valid ndm_flag for a dump request
When dumping proxy entries the dump request has NTF_PROXY set in
ndm_flags. strict mode checking needs to be updated to allow this
flag.

Fixes: 51183d233b ("net/neighbor: Update neigh_dump_info for strict data checking")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 17:30:47 -08:00
David Ahern
754d5da631 neighbor: Initialize protocol when new pneigh_entry are created
pneigh_lookup uses kmalloc versus kzalloc when new entries are allocated.
Given that the newly added protocol field needs to be initialized.

Fixes: df9b0e30d4 ("neighbor: Add protocol attribute")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 17:29:45 -08:00
Lorenzo Bianconi
8e1da73acd gro_cell: add napi_disable in gro_cells_destroy
Add napi_disable routine in gro_cells_destroy since starting from
commit c42858eaf4 ("gro_cells: remove spinlock protecting receive
queues") gro_cell_poll and gro_cells_destroy can run concurrently on
napi_skbs list producing a kernel Oops if the tunnel interface is
removed while gro_cell_poll is running. The following Oops has been
triggered removing a vxlan device while the interface is receiving
traffic

[ 5628.948853] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[ 5628.949981] PGD 0 P4D 0
[ 5628.950308] Oops: 0002 [#1] SMP PTI
[ 5628.950748] CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 4.20.0-rc6+ #41
[ 5628.952940] RIP: 0010:gro_cell_poll+0x49/0x80
[ 5628.955615] RSP: 0018:ffffc9000004fdd8 EFLAGS: 00010202
[ 5628.956250] RAX: 0000000000000000 RBX: ffffe8ffffc08150 RCX: 0000000000000000
[ 5628.957102] RDX: 0000000000000000 RSI: ffff88802356bf00 RDI: ffffe8ffffc08150
[ 5628.957940] RBP: 0000000000000026 R08: 0000000000000000 R09: 0000000000000000
[ 5628.958803] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000040
[ 5628.959661] R13: ffffe8ffffc08100 R14: 0000000000000000 R15: 0000000000000040
[ 5628.960682] FS:  0000000000000000(0000) GS:ffff88803ea00000(0000) knlGS:0000000000000000
[ 5628.961616] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5628.962359] CR2: 0000000000000008 CR3: 000000000221c000 CR4: 00000000000006b0
[ 5628.963188] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 5628.964034] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 5628.964871] Call Trace:
[ 5628.965179]  net_rx_action+0xf0/0x380
[ 5628.965637]  __do_softirq+0xc7/0x431
[ 5628.966510]  run_ksoftirqd+0x24/0x30
[ 5628.966957]  smpboot_thread_fn+0xc5/0x160
[ 5628.967436]  kthread+0x113/0x130
[ 5628.968283]  ret_from_fork+0x3a/0x50
[ 5628.968721] Modules linked in:
[ 5628.969099] CR2: 0000000000000008
[ 5628.969510] ---[ end trace 9d9dedc7181661fe ]---
[ 5628.970073] RIP: 0010:gro_cell_poll+0x49/0x80
[ 5628.972965] RSP: 0018:ffffc9000004fdd8 EFLAGS: 00010202
[ 5628.973611] RAX: 0000000000000000 RBX: ffffe8ffffc08150 RCX: 0000000000000000
[ 5628.974504] RDX: 0000000000000000 RSI: ffff88802356bf00 RDI: ffffe8ffffc08150
[ 5628.975462] RBP: 0000000000000026 R08: 0000000000000000 R09: 0000000000000000
[ 5628.976413] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000040
[ 5628.977375] R13: ffffe8ffffc08100 R14: 0000000000000000 R15: 0000000000000040
[ 5628.978296] FS:  0000000000000000(0000) GS:ffff88803ea00000(0000) knlGS:0000000000000000
[ 5628.979327] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 5628.980044] CR2: 0000000000000008 CR3: 000000000221c000 CR4: 00000000000006b0
[ 5628.980929] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 5628.981736] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 5628.982409] Kernel panic - not syncing: Fatal exception in interrupt
[ 5628.983307] Kernel Offset: disabled

Fixes: c42858eaf4 ("gro_cells: remove spinlock protecting receive queues")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 15:50:02 -08:00
Roopa Prabhu
82cbb5c631 neighbour: register rtnl doit handler
this patch registers neigh doit handler. The doit handler
returns a neigh entry given dst and dev. This is similar
to route and fdb doit (get) handlers. Also moves nda_policy
declaration from rtnetlink.c to neighbour.c

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 13:37:34 -08:00
Florian Westphal
4165079ba3 net: switch secpath to use skb extension infrastructure
Remove skb->sp and allocate secpath storage via extension
infrastructure.  This also reduces sk_buff by 8 bytes on x86_64.

Total size of allyesconfig kernel is reduced slightly, as there is
less inlined code (one conditional atomic op instead of two on
skb_clone).

No differences in throughput in following ipsec performance tests:
- transport mode with aes on 10GB link
- tunnel mode between two network namespaces with aes and null cipher

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 11:21:38 -08:00
Florian Westphal
de8bda1d22 net: convert bridge_nf to use skb extension infrastructure
This converts the bridge netfilter (calling iptables hooks from bridge)
facility to use the extension infrastructure.

The bridge_nf specific hooks in skb clone and free paths are removed, they
have been replaced by the skb_ext hooks that do the same as the bridge nf
allocations hooks did.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 11:21:37 -08:00
Florian Westphal
df5042f4c5 sk_buff: add skb extension infrastructure
This adds an optional extension infrastructure, with ispec (xfrm) and
bridge netfilter as first users.
objdiff shows no changes if kernel is built without xfrm and br_netfilter
support.

The third (planned future) user is Multipath TCP which is still
out-of-tree.
MPTCP needs to map logical mptcp sequence numbers to the tcp sequence
numbers used by individual subflows.

This DSS mapping is read/written from tcp option space on receive and
written to tcp option space on transmitted tcp packets that are part of
and MPTCP connection.

Extending skb_shared_info or adding a private data field to skb fclones
doesn't work for incoming skb, so a different DSS propagation method would
be required for the receive side.

mptcp has same requirements as secpath/bridge netfilter:

1. extension memory is released when the sk_buff is free'd.
2. data is shared after cloning an skb (clone inherits extension)
3. adding extension to an skb will COW the extension buffer if needed.

The "MPTCP upstreaming" effort adds SKB_EXT_MPTCP extension to store the
mapping for tx and rx processing.

Two new members are added to sk_buff:
1. 'active_extensions' byte (filling a hole), telling which extensions
   are available for this skb.
   This has two purposes.
   a) avoids the need to initialize the pointer.
   b) allows to "delete" an extension by clearing its bit
   value in ->active_extensions.

   While it would be possible to store the active_extensions byte
   in the extension struct instead of sk_buff, there is one problem
   with this:
    When an extension has to be disabled, we can always clear the
    bit in skb->active_extensions.  But in case it would be stored in the
    extension buffer itself, we might have to COW it first, if
    we are dealing with a cloned skb.  On kmalloc failure we would
    be unable to turn an extension off.

2. extension pointer, located at the end of the sk_buff.
   If the active_extensions byte is 0, the pointer is undefined,
   it is not initialized on skb allocation.

This adds extra code to skb clone and free paths (to deal with
refcount/free of extension area) but this replaces similar code that
manages skb->nf_bridge and skb->sp structs in the followup patches of
the series.

It is possible to add support for extensions that are not preseved on
clones/copies.

To do this, it would be needed to define a bitmask of all extensions that
need copy/cow semantics, and change __skb_ext_copy() to check
->active_extensions & SKB_EXT_PRESERVE_ON_CLONE, then just set
->active_extensions to 0 on the new clone.

This isn't done here because all extensions that get added here
need the copy/cow semantics.

v2:
Allocate entire extension space using kmem_cache.
Upside is that this allows better tracking of used memory,
downside is that we will allocate more space than strictly needed in
most cases (its unlikely that all extensions are active/needed at same
time for same skb).
The allocated memory (except the small extension header) is not cleared,
so no additonal overhead aside from memory usage.

Avoid atomic_dec_and_test operation on skb_ext_put()
by using similar trick as kfree_skbmem() does with fclone_ref:
If recount is 1, there is no concurrent user and we can free right away.

Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-19 11:21:37 -08:00
John Fastabend
3bdbd0228e bpf: sockmap, metadata support for reporting size of msg
This adds metadata to sk_msg_md for BPF programs to read the sk_msg
size.

When the SK_MSG program is running under an application that is using
sendfile the data is not copied into sk_msg buffers by default. Rather
the BPF program uses sk_msg_pull_data to read the bytes in. This
avoids doing the costly memcopy instructions when they are not in
fact needed. However, if we don't know the size of the sk_msg we
have to guess if needed bytes are available by doing a pull request
which may fail. By including the size of the sk_msg BPF programs can
check the size before issuing sk_msg_pull_data requests.

Additionally, the same applies for sendmsg calls when the application
provides multiple iovs. Here the BPF program needs to pull in data
to update data pointers but its not clear where the data ends without
a size parameter. In many cases "guessing" is not easy to do
and results in multiple calls to pull and without bounded loops
everything gets fairly tricky.

Clean this up by including a u32 size field. Note, all writes into
sk_msg_md are rejected already from sk_msg_is_valid_access so nothing
additional is needed there.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-12-19 00:27:23 +01:00
Roopa Prabhu
5b2f94b276 net: rtnetlink: support for fdb get
This patch adds support for fdb get similar to
route get. arguments can be any of the following (similar to fdb add/del/dump):
[bridge, mac, vlan] or
[bridge_port, mac, vlan, flags=[NTF_MASTER]] or
[dev, mac, [vni|vlan], flags=[NTF_SELF]]

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>
Reviewed-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-16 14:42:34 -08:00
David Ahern
df9b0e30d4 neighbor: Add protocol attribute
Similar to routes and rules, add protocol attribute to neighbor entries
for easier tracking of how each was created.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-16 12:15:25 -08:00
Paolo Abeni
aaa5d90b39 net: use indirect call wrappers at GRO network layer
This avoids an indirect calls for L3 GRO receive path, both
for ipv4 and ipv6, if the latter is not compiled as a module.

Note that when IPv6 is compiled as builtin, it will be checked first,
so we have a single additional compare for the more common path.

v1 -> v2:
 - adapted to INDIRECT_CALL_ changes

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-15 13:23:02 -08:00
David Ahern
e997f8a20a neighbor: Remove externally learned entries from gc_list
Externally learned entries are similar to PERMANENT entries in the
sense they are managed by userspace and can not be garbage collected.
As such remove them from the gc_list, remove the flags check from
neigh_forced_gc and skip threshold checks in neigh_alloc. As with
PERMANENT entries, this allows unlimited number of NTF_EXT_LEARNED
entries.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-14 15:44:47 -08:00
David Ahern
526f1b587c neighbor: Move neigh_update_ext_learned to core file
neigh_update_ext_learned has one caller in neighbour.c so does not need
to be defined in the header. Move it and in the process remove the
intialization of ndm_flags and just set it based on the flags check.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-14 15:44:47 -08:00
David Ahern
7e6f182bec neighbor: Remove state and flags arguments to neigh_del
neigh_del now only has 1 caller, and the state and flags arguments
are both 0. Remove them and simplify neigh_del.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-14 15:44:47 -08:00
David Ahern
758a7f0b32 neighbor: Fix state check in neigh_forced_gc
PERMANENT entries are not on the gc_list so the state check is now
redundant. Also, the move to not purge entries until after 5 seconds
should not apply to FAILED entries; those can be removed immediately
to make way for newer ones. This restores the previous logic prior to
the gc_list.

Fixes: 58956317c8 ("neighbor: Improve garbage collection")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-14 15:44:47 -08:00
David Ahern
9c29a2f55e neighbor: Fix locking order for gc_list changes
Lock checker noted an inverted lock order between neigh_change_state
(neighbor lock then table lock) and neigh_periodic_work (table lock and
then neighbor lock) resulting in:

[  121.057652] ======================================================
[  121.058740] WARNING: possible circular locking dependency detected
[  121.059861] 4.20.0-rc6+ #43 Not tainted
[  121.060546] ------------------------------------------------------
[  121.061630] kworker/0:2/65 is trying to acquire lock:
[  121.062519] (____ptrval____) (&n->lock){++--}, at: neigh_periodic_work+0x237/0x324
[  121.063894]
[  121.063894] but task is already holding lock:
[  121.064920] (____ptrval____) (&tbl->lock){+.-.}, at: neigh_periodic_work+0x194/0x324
[  121.066274]
[  121.066274] which lock already depends on the new lock.
[  121.066274]
[  121.067693]
[  121.067693] the existing dependency chain (in reverse order) is:
...

Fix by renaming neigh_change_state to neigh_update_gc_list, changing
it to only manage whether an entry should be on the gc_list and taking
locks in the same order as neigh_periodic_work. Invoke at the end of
neigh_update only if diff between old or new states has the PERMANENT
flag set.

Fixes: 8cc196d6ef ("neighbor: gc_list changes should be protected by table lock")
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-14 15:44:47 -08:00
Petr Machata
d59cdf9475 net: dev: Issue NETDEV_PRE_CHANGEADDR
When a device address is about to be changed, or an address added to the
list of device HW addresses, it is necessary to ensure that all
interested parties can support the address. Therefore, send the
NETDEV_PRE_CHANGEADDR notification, and if anyone bails on it, do not
change the address.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-13 18:41:38 -08:00
Petr Machata
1570415f08 net: dev: Add NETDEV_PRE_CHANGEADDR
The NETDEV_CHANGEADDR notification is emitted after a device address
changes. Extending this message to allow vetoing is certainly possible,
but several other notification types have instead adopted a simple
two-stage approach: first a "pre" notification is sent to make sure all
interested parties are OK with a change that's about to be done. Then
the change is done, and afterwards a "post" notification is sent.

This dual approach is easier to use: when the change is vetoed, nothing
has changed yet, and it's therefore unnecessary to roll anything back.
Therefore adopt it for NETDEV_CHANGEADDR as well.

To that end, add NETDEV_PRE_CHANGEADDR and an info structure to go along
with it.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-13 18:41:38 -08:00
Petr Machata
3a37a9636c net: dev: Add extack argument to dev_set_mac_address()
A follow-up patch will add a notifier type NETDEV_PRE_CHANGEADDR, which
allows vetoing of MAC address changes. One prominent path to that
notification is through dev_set_mac_address(). Therefore give this
function an extack argument, so that it can be packed together with the
notification. Thus a textual reason for rejection (or a warning) can be
communicated back to the user.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-13 18:41:38 -08:00
Petr Machata
2fd527b72b net: ndo_bridge_setlink: Add extack
Drivers may not be able to implement a VLAN addition or reconfiguration.
In those cases it's desirable to explain to the user that it was
rejected (and why).

To that end, add extack argument to ndo_bridge_setlink. Adapt all users
to that change.

Following patches will use the new argument in the bridge driver.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-12 16:34:21 -08:00
Daniel Borkmann
fdadd04931 bpf: fix bpf_jit_limit knob for PAGE_SIZE >= 64K
Michael and Sandipan report:

  Commit ede95a63b5 introduced a bpf_jit_limit tuneable to limit BPF
  JIT allocations. At compile time it defaults to PAGE_SIZE * 40000,
  and is adjusted again at init time if MODULES_VADDR is defined.

  For ppc64 kernels, MODULES_VADDR isn't defined, so we're stuck with
  the compile-time default at boot-time, which is 0x9c400000 when
  using 64K page size. This overflows the signed 32-bit bpf_jit_limit
  value:

  root@ubuntu:/tmp# cat /proc/sys/net/core/bpf_jit_limit
  -1673527296

  and can cause various unexpected failures throughout the network
  stack. In one case `strace dhclient eth0` reported:

  setsockopt(5, SOL_SOCKET, SO_ATTACH_FILTER, {len=11, filter=0x105dd27f8},
             16) = -1 ENOTSUPP (Unknown error 524)

  and similar failures can be seen with tools like tcpdump. This doesn't
  always reproduce however, and I'm not sure why. The more consistent
  failure I've seen is an Ubuntu 18.04 KVM guest booted on a POWER9
  host would time out on systemd/netplan configuring a virtio-net NIC
  with no noticeable errors in the logs.

Given this and also given that in near future some architectures like
arm64 will have a custom area for BPF JIT image allocations we should
get rid of the BPF_JIT_LIMIT_DEFAULT fallback / default entirely. For
4.21, we have an overridable bpf_jit_alloc_exec(), bpf_jit_free_exec()
so therefore add another overridable bpf_jit_alloc_exec_limit() helper
function which returns the possible size of the memory area for deriving
the default heuristic in bpf_jit_charge_init().

Like bpf_jit_alloc_exec() and bpf_jit_free_exec(), the new
bpf_jit_alloc_exec_limit() assumes that module_alloc() is the default
JIT memory provider, and therefore in case archs implement their custom
module_alloc() we use MODULES_{END,_VADDR} for limits and otherwise for
vmalloc_exec() cases like on ppc64 we use VMALLOC_{END,_START}.

Additionally, for archs supporting large page sizes, we should change
the sysctl to be handled as long to not run into sysctl restrictions
in future.

Fixes: ede95a63b5 ("bpf: add bpf_jit_limit knob to restrict unpriv allocations")
Reported-by: Sandipan Das <sandipan@linux.ibm.com>
Reported-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-11 19:12:21 -08:00
David S. Miller
addb067983 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2018-12-11

The following pull-request contains BPF updates for your *net-next* tree.

It has three minor merge conflicts, resolutions:

1) tools/testing/selftests/bpf/test_verifier.c

 Take first chunk with alignment_prevented_execution.

2) net/core/filter.c

  [...]
  case bpf_ctx_range_ptr(struct __sk_buff, flow_keys):
  case bpf_ctx_range(struct __sk_buff, wire_len):
        return false;
  [...]

3) include/uapi/linux/bpf.h

  Take the second chunk for the two cases each.

The main changes are:

1) Add support for BPF line info via BTF and extend libbpf as well
   as bpftool's program dump to annotate output with BPF C code to
   facilitate debugging and introspection, from Martin.

2) Add support for BPF_ALU | BPF_ARSH | BPF_{K,X} in interpreter
   and all JIT backends, from Jiong.

3) Improve BPF test coverage on archs with no efficient unaligned
   access by adding an "any alignment" flag to the BPF program load
   to forcefully disable verifier alignment checks, from David.

4) Add a new bpf_prog_test_run_xattr() API to libbpf which allows for
   proper use of BPF_PROG_TEST_RUN with data_out, from Lorenz.

5) Extend tc BPF programs to use a new __sk_buff field called wire_len
   for more accurate accounting of packets going to wire, from Petar.

6) Improve bpftool to allow dumping the trace pipe from it and add
   several improvements in bash completion and map/prog dump,
   from Quentin.

7) Optimize arm64 BPF JIT to always emit movn/movk/movk sequence for
   kernel addresses and add a dedicated BPF JIT backend allocator,
   from Ard.

8) Add a BPF helper function for IR remotes to report mouse movements,
   from Sean.

9) Various cleanups in BPF prog dump e.g. to make UAPI bpf_prog_info
   member naming consistent with existing conventions, from Yonghong
   and Song.

10) Misc cleanups and improvements in allowing to pass interface name
    via cmdline for xdp1 BPF example, from Matteo.

11) Fix a potential segfault in BPF sample loader's kprobes handling,
    from Daniel T.

12) Fix SPDX license in libbpf's README.rst, from Andrey.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-10 18:00:43 -08:00
David Ahern
8cc196d6ef neighbor: gc_list changes should be protected by table lock
Adding and removing neighbor entries to / from the gc_list need to be
done while holding the table lock; a couple of places were missed in the
original patch.

Move the list_add_tail in neigh_alloc to ___neigh_create where the lock
is already obtained. Since neighbor entries should rarely be moved
to/from PERMANENT state, add lock/unlock around the gc_list changes in
neigh_change_state rather than extending the lock hold around all
neighbor updates.

Fixes: 58956317c8 ("neighbor: Improve garbage collection")
Reported-by: Andrei Vagin <avagin@gmail.com>
Reported-by: syzbot+6cc2fd1d3bdd2e007363@syzkaller.appspotmail.com
Reported-by: syzbot+35e87b87c00f386b041f@syzkaller.appspotmail.com
Reported-by: syzbot+b354d1fb59091ea73c37@syzkaller.appspotmail.com
Reported-by: syzbot+3ddead5619658537909b@syzkaller.appspotmail.com
Reported-by: syzbot+424d47d5c456ce8b2bbe@syzkaller.appspotmail.com
Reported-by: syzbot+e4d42eb35f6a27b0a628@syzkaller.appspotmail.com
Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-10 17:41:35 -08:00
David S. Miller
4cc1feeb6f Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Several conflicts, seemingly all over the place.

I used Stephen Rothwell's sample resolutions for many of these, if not
just to double check my own work, so definitely the credit largely
goes to him.

The NFP conflict consisted of a bug fix (moving operations
past the rhashtable operation) while chaning the initial
argument in the function call in the moved code.

The net/dsa/master.c conflict had to do with a bug fix intermixing of
making dsa_master_set_mtu() static with the fixing of the tagging
attribute location.

cls_flower had a conflict because the dup reject fix from Or
overlapped with the addition of port range classifiction.

__set_phy_supported()'s conflict was relatively easy to resolve
because Andrew fixed it in both trees, so it was just a matter
of taking the net-next copy.  Or at least I think it was :-)

Joe Stringer's fix to the handling of netns id 0 in bpf_sk_lookup()
intermixed with changes on how the sdif and caller_net are calculated
in these code paths in net-next.

The remaining BPF conflicts were largely about the addition of the
__bpf_md_ptr stuff in 'net' overlapping with adjustments and additions
to the relevant data structure where the MD pointer macros are used.

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-09 21:43:31 -08:00
yupeng
0fbe82e628 net: call sk_dst_reset when set SO_DONTROUTE
after set SO_DONTROUTE to 1, the IP layer should not route packets if
the dest IP address is not in link scope. But if the socket has cached
the dst_entry, such packets would be routed until the sk_dst_cache
expires. So we should clean the sk_dst_cache when a user set
SO_DONTROUTE option. Below are server/client python scripts which
could reprodue this issue:

server side code:

==========================================================================
import socket
import struct
import time

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind(('0.0.0.0', 9000))
s.listen(1)
sock, addr = s.accept()
sock.setsockopt(socket.SOL_SOCKET, socket.SO_DONTROUTE, struct.pack('i', 1))
while True:
    sock.send(b'foo')
    time.sleep(1)
==========================================================================

client side code:
==========================================================================
import socket
import time

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect(('server_address', 9000))
while True:
    data = s.recv(1024)
    print(data)
==========================================================================

Signed-off-by: yupeng <yupeng0921@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-07 16:11:54 -08:00
David Ahern
58956317c8 neighbor: Improve garbage collection
The existing garbage collection algorithm has a number of problems:

1. The gc algorithm will not evict PERMANENT entries as those entries
   are managed by userspace, yet the existing algorithm walks the entire
   hash table which means it always considers PERMANENT entries when
   looking for entries to evict. In some use cases (e.g., EVPN) there
   can be tens of thousands of PERMANENT entries leading to wasted
   CPU cycles when gc kicks in. As an example, with 32k permanent
   entries, neigh_alloc has been observed taking more than 4 msec per
   invocation.

2. Currently, when the number of neighbor entries hits gc_thresh2 and
   the last flush for the table was more than 5 seconds ago gc kicks in
   walks the entire hash table evicting *all* entries not in PERMANENT
   or REACHABLE state and not marked as externally learned. There is no
   discriminator on when the neigh entry was created or if it just moved
   from REACHABLE to another NUD_VALID state (e.g., NUD_STALE).

   It is possible for entries to be created or for established neighbor
   entries to be moved to STALE (e.g., an external node sends an ARP
   request) right before the 5 second window lapses:

        -----|---------x|----------|-----
            t-5         t         t+5

   If that happens those entries are evicted during gc causing unnecessary
   thrashing on neighbor entries and userspace caches trying to track them.

   Further, this contradicts the description of gc_thresh2 which says
   "Entries older than 5 seconds will be cleared".

   One workaround is to make gc_thresh2 == gc_thresh3 but that negates the
   whole point of having separate thresholds.

3. Clearing *all* neigh non-PERMANENT/REACHABLE/externally learned entries
   when gc_thresh2 is exceeded is over kill and contributes to trashing
   especially during startup.

This patch addresses these problems as follows:

1. Use of a separate list_head to track entries that can be garbage
   collected along with a separate counter. PERMANENT entries are not
   added to this list.

   The gc_thresh parameters are only compared to the new counter, not the
   total entries in the table. The forced_gc function is updated to only
   walk this new gc_list looking for entries to evict.

2. Entries are added to the list head at the tail and removed from the
   front.

3. Entries are only evicted if they were last updated more than 5 seconds
   ago, adhering to the original intent of gc_thresh2.

4. Forced gc is stopped once the number of gc_entries drops below
   gc_thresh2.

5. Since gc checks do not apply to PERMANENT entries, gc levels are skipped
   when allocating a new neighbor for a PERMANENT entry. By extension this
   means there are no explicit limits on the number of PERMANENT entries
   that can be created, but this is no different than FIB entries or FDB
   entries.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-07 16:03:10 -08:00
Stanislav Fomichev
ec3d837aac net/flow_dissector: correctly cap nhoff and thoff in case of BPF
We want to make sure that the following condition holds:
0 <= nhoff <= thoff <= skb->len

BPF program can set out-of-bounds nhoff and thoff, which is dangerous, see
recent commit d0c081b491 ("flow_dissector: properly cap thoff field")'.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-07 13:38:29 -08:00
Stanislav Fomichev
13e56ec2cc selftests/bpf: use thoff instead of nhoff in BPF flow dissector
We are returning thoff from the flow dissector, not the nhoff. Pass
thoff along with nhoff to the bpf program (initially thoff == nhoff)
and expect flow dissector amend/return thoff, not nhoff.

This avoids confusion, when by the time bpf flow dissector exits,
nhoff == thoff, which doesn't make much sense.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-12-07 13:38:12 -08:00
Petr Machata
40c900aa1f net: core: dev: Attach extack to NETDEV_PRE_UP
Drivers may need to validate configuration of a device that's about to
be upped. Should the validation fail, there's currently no way to
communicate details of the failure to the user, beyond an error number.

To mend that, change __dev_open() to take an extack argument and pass it
from __dev_change_flags() and dev_open(), where it was propagated in the
previous patches.

Change __dev_open() to call call_netdevice_notifiers_extack() so that
the passed-in extack is attached to the NETDEV_PRE_UP notifier.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-06 13:26:07 -08:00
Petr Machata
2637260534 net: core: dev: Add call_netdevice_notifiers_extack()
In order to propagate extack through NETDEV_PRE_UP, add a new function
call_netdevice_notifiers_extack() that primes the extack field of the
notifier info. Convert call_netdevice_notifiers() to a simple wrapper
around the new function that passes NULL for extack.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-06 13:26:07 -08:00
Petr Machata
6d0403216d net: core: dev: Add extack argument to __dev_change_flags()
In order to pass extack together with NETDEV_PRE_UP notifications, it's
necessary to route the extack to __dev_open() from diverse (possibly
indirect) callers. The last missing API is __dev_change_flags().

Therefore extend __dev_change_flags() with and extra extack argument and
update the two existing users.

Since the function declaration line is changed anyway, name the struct
net_device argument to placate checkpatch.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-06 13:26:07 -08:00
Petr Machata
567c5e13be net: core: dev: Add extack argument to dev_change_flags()
In order to pass extack together with NETDEV_PRE_UP notifications, it's
necessary to route the extack to __dev_open() from diverse (possibly
indirect) callers. One prominent API through which the notification is
invoked is dev_change_flags().

Therefore extend dev_change_flags() with and extra extack argument and
update all users. Most of the calls end up just encoding NULL, but
several sites (VLAN, ipvlan, VRF, rtnetlink) do have extack available.

Since the function declaration line is changed anyway, name the other
function arguments to placate checkpatch.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-06 13:26:07 -08:00
Petr Machata
00f54e6892 net: core: dev: Add extack argument to dev_open()
In order to pass extack together with NETDEV_PRE_UP notifications, it's
necessary to route the extack to __dev_open() from diverse (possibly
indirect) callers. One prominent API through which the notification is
invoked is dev_open().

Therefore extend dev_open() with and extra extack argument and update
all users. Most of the calls end up just encoding NULL, but bond and
team drivers have the extack readily available.

Signed-off-by: Petr Machata <petrm@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-06 13:26:06 -08:00
David Ahern
7a35a50df5 neighbor: Add extack messages for add and delete commands
Add extack messages for failures in neigh_add and neigh_delete.

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-05 20:53:19 -08:00
David S. Miller
e37d05a538 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================
pull-request: bpf 2018-12-05

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) fix bpf uapi pointers for 32-bit architectures, from Daniel.

2) improve verifer ability to handle progs with a lot of branches, from Alexei.

3) strict btf checks, from Yonghong.

4) bpf_sk_lookup api cleanup, from Joe.

5) other misc fixes
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-05 16:30:30 -08:00
Edward Cree
22f6bbb7bc net: use skb_list_del_init() to remove from RX sublists
list_del() leaves the skb->next pointer poisoned, which can then lead to
 a crash in e.g. OVS forwarding.  For example, setting up an OVS VXLAN
 forwarding bridge on sfc as per:

========
$ ovs-vsctl show
5dfd9c47-f04b-4aaa-aa96-4fbb0a522a30
    Bridge "br0"
        Port "br0"
            Interface "br0"
                type: internal
        Port "enp6s0f0"
            Interface "enp6s0f0"
        Port "vxlan0"
            Interface "vxlan0"
                type: vxlan
                options: {key="1", local_ip="10.0.0.5", remote_ip="10.0.0.4"}
    ovs_version: "2.5.0"
========
(where 10.0.0.5 is an address on enp6s0f1)
and sending traffic across it will lead to the following panic:
========
general protection fault: 0000 [#1] SMP PTI
CPU: 5 PID: 0 Comm: swapper/5 Not tainted 4.20.0-rc3-ehc+ #701
Hardware name: Dell Inc. PowerEdge R710/0M233H, BIOS 6.4.0 07/23/2013
RIP: 0010:dev_hard_start_xmit+0x38/0x200
Code: 53 48 89 fb 48 83 ec 20 48 85 ff 48 89 54 24 08 48 89 4c 24 18 0f 84 ab 01 00 00 48 8d 86 90 00 00 00 48 89 f5 48 89 44 24 10 <4c> 8b 33 48 c7 03 00 00 00 00 48 8b 05 c7 d1 b3 00 4d 85 f6 0f 95
RSP: 0018:ffff888627b437e0 EFLAGS: 00010202
RAX: 0000000000000000 RBX: dead000000000100 RCX: ffff88862279c000
RDX: ffff888614a342c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888618a88000 R08: 0000000000000001 R09: 00000000000003e8
R10: 0000000000000000 R11: ffff888614a34140 R12: 0000000000000000
R13: 0000000000000062 R14: dead000000000100 R15: ffff888616430000
FS:  0000000000000000(0000) GS:ffff888627b40000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6d2bc6d000 CR3: 000000000200a000 CR4: 00000000000006e0
Call Trace:
 <IRQ>
 __dev_queue_xmit+0x623/0x870
 ? masked_flow_lookup+0xf7/0x220 [openvswitch]
 ? ep_poll_callback+0x101/0x310
 do_execute_actions+0xaba/0xaf0 [openvswitch]
 ? __wake_up_common+0x8a/0x150
 ? __wake_up_common_lock+0x87/0xc0
 ? queue_userspace_packet+0x31c/0x5b0 [openvswitch]
 ovs_execute_actions+0x47/0x120 [openvswitch]
 ovs_dp_process_packet+0x7d/0x110 [openvswitch]
 ovs_vport_receive+0x6e/0xd0 [openvswitch]
 ? dst_alloc+0x64/0x90
 ? rt_dst_alloc+0x50/0xd0
 ? ip_route_input_slow+0x19a/0x9a0
 ? __udp_enqueue_schedule_skb+0x198/0x1b0
 ? __udp4_lib_rcv+0x856/0xa30
 ? __udp4_lib_rcv+0x856/0xa30
 ? cpumask_next_and+0x19/0x20
 ? find_busiest_group+0x12d/0xcd0
 netdev_frame_hook+0xce/0x150 [openvswitch]
 __netif_receive_skb_core+0x205/0xae0
 __netif_receive_skb_list_core+0x11e/0x220
 netif_receive_skb_list+0x203/0x460
 ? __efx_rx_packet+0x335/0x5e0 [sfc]
 efx_poll+0x182/0x320 [sfc]
 net_rx_action+0x294/0x3c0
 __do_softirq+0xca/0x297
 irq_exit+0xa6/0xb0
 do_IRQ+0x54/0xd0
 common_interrupt+0xf/0xf
 </IRQ>
========
So, in all listified-receive handling, instead pull skbs off the lists with
 skb_list_del_init().

Fixes: 9af86f9338 ("net: core: fix use-after-free in __netif_receive_skb_list_core")
Fixes: 7da517a3bc ("net: core: Another step of skb receive list processing")
Fixes: a4ca8b7df7 ("net: ipv4: fix drop handling in ip_list_rcv() and ip_list_rcv_finish()")
Fixes: d8269e2cbf ("net: ipv6: listify ipv6_rcv() and ip6_rcv_finish()")
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-05 16:22:05 -08:00
Eric Dumazet
a74f0fa082 tcp: reduce POLLOUT events caused by TCP_NOTSENT_LOWAT
TCP_NOTSENT_LOWAT socket option or sysctl was added in linux-3.12
as a step to enable bigger tcp sndbuf limits.

It works reasonably well, but the following happens :

Once the limit is reached, TCP stack generates
an [E]POLLOUT event for every incoming ACK packet.

This causes a high number of context switches.

This patch implements the strategy David Miller added
in sock_def_write_space() :

 - If TCP socket has a notsent_lowat constraint of X bytes,
   allow sendmsg() to fill up to X bytes, but send [E]POLLOUT
   only if number of notsent bytes is below X/2

This considerably reduces TCP_NOTSENT_LOWAT overhead,
while allowing to keep the pipe full.

Tested:
 100 ms RTT netem testbed between A and B, 100 concurrent TCP_STREAM

A:/# cat /proc/sys/net/ipv4/tcp_wmem
4096	262144	64000000
A:/# super_netperf 100 -H B -l 1000 -- -K bbr &

A:/# grep TCP /proc/net/sockstat
TCP: inuse 203 orphan 0 tw 19 alloc 414 mem 1364904 # This is about 54 MB of memory per flow :/

A:/# vmstat 5 5
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 0  0      0 256220672  13532 694976    0    0    10     0   28   14  0  1 99  0  0
 2  0      0 256320016  13532 698480    0    0   512     0 715901 5927  0 10 90  0  0
 0  0      0 256197232  13532 700992    0    0   735    13 771161 5849  0 11 89  0  0
 1  0      0 256233824  13532 703320    0    0   512    23 719650 6635  0 11 89  0  0
 2  0      0 256226880  13532 705780    0    0   642     4 775650 6009  0 12 88  0  0

A:/# echo 2097152 >/proc/sys/net/ipv4/tcp_notsent_lowat

A:/# grep TCP /proc/net/sockstat
TCP: inuse 203 orphan 0 tw 19 alloc 414 mem 86411 # 3.5 MB per flow

A:/# vmstat 5 5  # check that context switches have not inflated too much.
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu-----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa st
 2  0      0 260386512  13592 662148    0    0    10     0   17   14  0  1 99  0  0
 0  0      0 260519680  13592 604184    0    0   512    13 726843 12424  0 10 90  0  0
 1  1      0 260435424  13592 598360    0    0   512    25 764645 12925  0 10 90  0  0
 1  0      0 260855392  13592 578380    0    0   512     7 722943 13624  0 11 88  0  0
 1  0      0 260445008  13592 601176    0    0   614    34 772288 14317  0 10 90  0  0

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-04 21:21:18 -08:00
Eric Dumazet
688838934c rtnetlink: ndo_dflt_fdb_dump() only work for ARPHRD_ETHER devices
kmsan was able to trigger a kernel-infoleak using a gre device [1]

nlmsg_populate_fdb_fill() has a hard coded assumption
that dev->addr_len is ETH_ALEN, as normally guaranteed
for ARPHRD_ETHER devices.

A similar issue was fixed recently in commit da71577545
("rtnetlink: Disallow FDB configuration for non-Ethernet device")

[1]
BUG: KMSAN: kernel-infoleak in copyout lib/iov_iter.c:143 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_iter+0x4c0/0x2700 lib/iov_iter.c:576
CPU: 0 PID: 6697 Comm: syz-executor310 Not tainted 4.20.0-rc3+ #95
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+0x32d/0x480 lib/dump_stack.c:113
 kmsan_report+0x12c/0x290 mm/kmsan/kmsan.c:683
 kmsan_internal_check_memory+0x32a/0xa50 mm/kmsan/kmsan.c:743
 kmsan_copy_to_user+0x78/0xd0 mm/kmsan/kmsan_hooks.c:634
 copyout lib/iov_iter.c:143 [inline]
 _copy_to_iter+0x4c0/0x2700 lib/iov_iter.c:576
 copy_to_iter include/linux/uio.h:143 [inline]
 skb_copy_datagram_iter+0x4e2/0x1070 net/core/datagram.c:431
 skb_copy_datagram_msg include/linux/skbuff.h:3316 [inline]
 netlink_recvmsg+0x6f9/0x19d0 net/netlink/af_netlink.c:1975
 sock_recvmsg_nosec net/socket.c:794 [inline]
 sock_recvmsg+0x1d1/0x230 net/socket.c:801
 ___sys_recvmsg+0x444/0xae0 net/socket.c:2278
 __sys_recvmsg net/socket.c:2327 [inline]
 __do_sys_recvmsg net/socket.c:2337 [inline]
 __se_sys_recvmsg+0x2fa/0x450 net/socket.c:2334
 __x64_sys_recvmsg+0x4a/0x70 net/socket.c:2334
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x441119
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 db 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fffc7f008a8 EFLAGS: 00000207 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000441119
RDX: 0000000000000040 RSI: 00000000200005c0 RDI: 0000000000000003
RBP: 00000000006cc018 R08: 0000000000000100 R09: 0000000000000100
R10: 0000000000000100 R11: 0000000000000207 R12: 0000000000402080
R13: 0000000000402110 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:246 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:261 [inline]
 kmsan_internal_chain_origin+0x13d/0x240 mm/kmsan/kmsan.c:469
 kmsan_memcpy_memmove_metadata+0x1a9/0xf70 mm/kmsan/kmsan.c:344
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:362
 __msan_memcpy+0x61/0x70 mm/kmsan/kmsan_instr.c:162
 __nla_put lib/nlattr.c:744 [inline]
 nla_put+0x20a/0x2d0 lib/nlattr.c:802
 nlmsg_populate_fdb_fill+0x444/0x810 net/core/rtnetlink.c:3466
 nlmsg_populate_fdb net/core/rtnetlink.c:3775 [inline]
 ndo_dflt_fdb_dump+0x73a/0x960 net/core/rtnetlink.c:3807
 rtnl_fdb_dump+0x1318/0x1cb0 net/core/rtnetlink.c:3979
 netlink_dump+0xc79/0x1c90 net/netlink/af_netlink.c:2244
 __netlink_dump_start+0x10c4/0x11d0 net/netlink/af_netlink.c:2352
 netlink_dump_start include/linux/netlink.h:216 [inline]
 rtnetlink_rcv_msg+0x141b/0x1540 net/core/rtnetlink.c:4910
 netlink_rcv_skb+0x394/0x640 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4965
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x1699/0x1740 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x13c7/0x1440 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xe3b/0x1240 net/socket.c:2116
 __sys_sendmsg net/socket.c:2154 [inline]
 __do_sys_sendmsg net/socket.c:2163 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2161
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:246 [inline]
 kmsan_internal_poison_shadow+0x6d/0x130 mm/kmsan/kmsan.c:170
 kmsan_kmalloc+0xa1/0x100 mm/kmsan/kmsan_hooks.c:186
 __kmalloc+0x14c/0x4d0 mm/slub.c:3825
 kmalloc include/linux/slab.h:551 [inline]
 __hw_addr_create_ex net/core/dev_addr_lists.c:34 [inline]
 __hw_addr_add_ex net/core/dev_addr_lists.c:80 [inline]
 __dev_mc_add+0x357/0x8a0 net/core/dev_addr_lists.c:670
 dev_mc_add+0x6d/0x80 net/core/dev_addr_lists.c:687
 ip_mc_filter_add net/ipv4/igmp.c:1128 [inline]
 igmp_group_added+0x4d4/0xb80 net/ipv4/igmp.c:1311
 __ip_mc_inc_group+0xea9/0xf70 net/ipv4/igmp.c:1444
 ip_mc_inc_group net/ipv4/igmp.c:1453 [inline]
 ip_mc_up+0x1c3/0x400 net/ipv4/igmp.c:1775
 inetdev_event+0x1d03/0x1d80 net/ipv4/devinet.c:1522
 notifier_call_chain kernel/notifier.c:93 [inline]
 __raw_notifier_call_chain kernel/notifier.c:394 [inline]
 raw_notifier_call_chain+0x13d/0x240 kernel/notifier.c:401
 __dev_notify_flags+0x3da/0x860 net/core/dev.c:1733
 dev_change_flags+0x1ac/0x230 net/core/dev.c:7569
 do_setlink+0x165f/0x5ea0 net/core/rtnetlink.c:2492
 rtnl_newlink+0x2ad7/0x35a0 net/core/rtnetlink.c:3111
 rtnetlink_rcv_msg+0x1148/0x1540 net/core/rtnetlink.c:4947
 netlink_rcv_skb+0x394/0x640 net/netlink/af_netlink.c:2477
 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4965
 netlink_unicast_kernel net/netlink/af_netlink.c:1310 [inline]
 netlink_unicast+0x1699/0x1740 net/netlink/af_netlink.c:1336
 netlink_sendmsg+0x13c7/0x1440 net/netlink/af_netlink.c:1917
 sock_sendmsg_nosec net/socket.c:621 [inline]
 sock_sendmsg net/socket.c:631 [inline]
 ___sys_sendmsg+0xe3b/0x1240 net/socket.c:2116
 __sys_sendmsg net/socket.c:2154 [inline]
 __do_sys_sendmsg net/socket.c:2163 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2161
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Bytes 36-37 of 105 are uninitialized
Memory access of size 105 starts at ffff88819686c000
Data copied to user address 0000000020000380

Fixes: d83b060360 ("net: add fdb generic dump routine")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Ido Schimmel <idosch@mellanox.com>
Cc: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-04 20:28:22 -08:00
Ido Schimmel
875e893995 skbuff: Rename 'offload_mr_fwd_mark' to 'offload_l3_fwd_mark'
Commit abf4bb6b63 ("skbuff: Add the offload_mr_fwd_mark field") added
the 'offload_mr_fwd_mark' field to indicate that a packet has already
undergone L3 multicast routing by a capable device. The field is used to
prevent the kernel from forwarding a packet through a netdev through
which the device has already forwarded the packet.

Currently, no unicast packet is routed by both the device and the
kernel, but this is about to change by subsequent patches and we need to
be able to mark such packets, so that they will no be forwarded twice.

Instead of adding yet another field to 'struct sk_buff', we can just
rename 'offload_mr_fwd_mark' to 'offload_l3_fwd_mark', as a packet
either has a multicast or a unicast destination IP.

While at it, add a comment about both 'offload_fwd_mark' and
'offload_l3_fwd_mark'.

Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-04 08:36:36 -08:00
Qian Cai
bf29e9e9b6 net/core: tidy up an error message
netif_napi_add() could report an error like this below due to it allows
to pass a format string for wildcarding before calling
dev_get_valid_name(),

"netif_napi_add() called with weight 256 on device eth%d"

For example, hns_enet_drv module does this.

hns_nic_try_get_ae
  hns_nic_init_ring_data
    netif_napi_add
  register_netdev
    dev_get_valid_name

Hence, make it a bit more human-readable by using netdev_err_once()
instead.

Signed-off-by: Qian Cai <cai@gmx.us>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-03 16:14:51 -08:00