With MSG_ZEROCOPY, each skb holds a reference to a struct ubuf_info.
Release of its last reference triggers a completion notification.
The TCP stack in tcp_sendmsg_locked holds an extra ref independent of
the skbs, because it can build, send and free skbs within its loop,
possibly reaching refcount zero and freeing the ubuf_info too soon.
The UDP stack currently also takes this extra ref, but does not need
it as all skbs are sent after return from __ip(6)_append_data.
Avoid the extra refcount_inc and refcount_dec_and_test, and generally
the sock_zerocopy_put in the common path, by passing the initial
reference to the first skb.
This approach is taken instead of initializing the refcount to 0, as
that would generate error "refcount_t: increment on 0" on the
next skb_zcopy_set.
Changes
v3 -> v4
- Move skb_zcopy_set below the only kfree_skb that might cause
a premature uarg destroy before skb_zerocopy_put_abort
- Move the entire skb_shinfo assignment block, to keep that
cacheline access in one place
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Extend zerocopy to udp sockets. Allow setting sockopt SO_ZEROCOPY and
interpret flag MSG_ZEROCOPY.
This patch was previously part of the zerocopy RFC patchsets. Zerocopy
is not effective at small MTU. With segmentation offload building
larger datagrams, the benefit of page flipping outweights the cost of
generating a completion notification.
tools/testing/selftests/net/msg_zerocopy.sh after applying follow-on
test patch and making skb_orphan_frags_rx same as skb_orphan_frags:
ipv4 udp -t 1
tx=191312 (11938 MB) txc=0 zc=n
rx=191312 (11938 MB)
ipv4 udp -z -t 1
tx=304507 (19002 MB) txc=304507 zc=y
rx=304507 (19002 MB)
ok
ipv6 udp -t 1
tx=174485 (10888 MB) txc=0 zc=n
rx=174485 (10888 MB)
ipv6 udp -z -t 1
tx=294801 (18396 MB) txc=294801 zc=y
rx=294801 (18396 MB)
ok
Changes
v1 -> v2
- Fixup reverse christmas tree violation
v2 -> v3
- Split refcount avoidance optimization into separate patch
- Fix refcount leak on error in fragmented case
(thanks to Paolo Abeni for pointing this one out!)
- Fix refcount inc on zero
- Test sock_flag SOCK_ZEROCOPY directly in __ip_append_data.
This is needed since commit 5cf4a8532c ("tcp: really ignore
MSG_ZEROCOPY if no SO_ZEROCOPY") did the same for tcp.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
I do not see how one can effectively use skb_insert() without holding
some kind of lock. Otherwise other cpus could have changed the list
right before we have a chance of acquiring list->lock.
Only existing user is in drivers/infiniband/hw/nes/nes_mgt.c and this
one probably meant to use __skb_insert() since it appears nesqp->pau_list
is protected by nesqp->pau_lock. This looks like nesqp->pau_lock
could be removed, since nesqp->pau_list.lock could be used instead.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Faisal Latif <faisal.latif@intel.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: linux-rdma <linux-rdma@vger.kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a packet is trapped and the corresponding SKB marked as
already-forwarded, it retains this marking even after it is forwarded
across veth links into another bridge. There, since it ingresses the
bridge over veth, which doesn't have offload_fwd_mark, it triggers a
warning in nbp_switchdev_frame_mark().
Then nbp_switchdev_allowed_egress() decides not to allow egress from
this bridge through another veth, because the SKB is already marked, and
the mark (of 0) of course matches. Thus the packet is incorrectly
blocked.
Solve by resetting offload_fwd_mark() in skb_scrub_packet(). That
function is called from tunnels and also from veth, and thus catches the
cases where traffic is forwarded between bridges and transformed in a
way that invalidates the marking.
Signed-off-by: Petr Machata <petrm@mellanox.com>
Suggested-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
if list is NULL pointer, and the following access of list
will trigger panic, which is same as BUG_ON
Signed-off-by: Li RongQing <lirongqing@baidu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently netdev_rx_csum_fault() only shows a device name,
we need more information about the skb for debugging csum
failures.
Sample output:
ens3: hw csum failure
dev features: 0x0000000000014b89
skb len=84 data_len=0 pkt_type=0 gso_size=0 gso_type=0 nr_frags=0 ip_summed=0 csum=0 csum_complete_sw=0 csum_valid=0 csum_level=0
Note, I use pr_err() just to be consistent with the existing one.
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This removes assumptions about VLAN_TAG_PRESENT bit.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
__skb_checksum_complete_head() and __skb_checksum_complete()
are both declared in skbuff.h, they fit better in skbuff.c
than datagram.c.
Cc: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Remove kernel-doc warning:
net/core/skbuff.c:4953: warning: Function parameter or member 'skb' not described in 'skb_gso_size_check'
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
David Ahern's dump indexing bug fix in 'net' overlapped the
change of the function signature of inet6_fill_ifaddr() in
'net-next'. Trivially resolved.
Signed-off-by: David S. Miller <davem@davemloft.net>
We've been getting checksum errors involving small UDP packets, usually
59B packets with 1 extra non-zero padding byte. netdev_rx_csum_fault()
has been complaining that HW is providing bad checksums. Turns out the
problem is in pskb_trim_rcsum_slow(), introduced in commit 88078d98d1
("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends").
The source of the problem is that when the bytes we are trimming start
at an odd address, as in the case of the 1 padding byte above,
skb_checksum() returns a byte-swapped value. We cannot just combine this
with skb->csum using csum_sub(). We need to use csum_block_sub() here
that takes into account the parity of the start address and handles the
swapping.
Matches existing code in __skb_postpull_rcsum() and esp_remove_trailer().
Fixes: 88078d98d1 ("net: pskb_trim_rcsum() and CHECKSUM_COMPLETE are friends")
Signed-off-by: Dimitris Michailidis <dmichail@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts were easy to resolve using immediate context mostly,
except the cls_u32.c one where I simply too the entire HEAD
chunk.
Signed-off-by: David S. Miller <davem@davemloft.net>
This helper is unused since commit 988cf74deb ("inet:
Stop generating UFO packets.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
According to the documentation in msg_zerocopy.rst, the SO_ZEROCOPY
flag was introduced because send(2) ignores unknown message flags and
any legacy application which was accidentally passing the equivalent of
MSG_ZEROCOPY earlier should not see any new behaviour.
Before commit f214f915e7 ("tcp: enable MSG_ZEROCOPY"), a send(2) call
which passed the equivalent of MSG_ZEROCOPY without setting SO_ZEROCOPY
would succeed. However, after that commit, it fails with -ENOBUFS. So
it appears that the SO_ZEROCOPY flag fails to fulfill its intended
purpose. Fix it.
Fixes: f214f915e7 ("tcp: enable MSG_ZEROCOPY")
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is needed for veth XDP which does skb_copy_expand()-like operation.
v2:
- Drop skb_copy_header part because it has already been exported now.
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested: see the next patch is the series.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 784abe24c9 ("net: Add decrypted field to skb")
introduced a 'decrypted' field that is explicitly copied on skb
copy and clone.
Move it between headers_start[0] and headers_end[0], so that we
don't need to copy it explicitly as it's copied by the memcpy()
in __copy_skb_header().
While at it, drop the assignment in __skb_clone(), it was
already redundant.
This doesn't change the size of sk_buff or cacheline boundaries.
The 15-bits hole before tc_index becomes a 14-bits hole, and
will be again a 15-bits hole when this change is merged with
commit 8b7008620b ("net: Don't copy pfmemalloc flag in
__copy_skb_header()").
v2: as reported by kbuild test robot (oops, I forgot to build
with CONFIG_TLS_DEVICE it seems), we can't use
CHECK_SKB_FIELD() on a bit-field member. Just drop the
check for the moment being, perhaps we could think of some
magic to also check bit-field members one day.
Fixes: 784abe24c9 ("net: Add decrypted field to skb")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The decrypted bit is propogated to cloned/copied skbs.
This will be used later by the inline crypto receive side offload
of tls.
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 8b7008620b ("net: Don't copy pfmemalloc flag in
__copy_skb_header()") introduced a different handling for the
pfmemalloc flag in copy and clone paths.
In __skb_clone(), now, the flag is set only if it was set in the
original skb, but not cleared if it wasn't. This is wrong and
might lead to socket buffers being flagged with pfmemalloc even
if the skb data wasn't allocated from pfmemalloc reserves. Copy
the flag instead of ORing it.
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Fixes: 8b7008620b ("net: Don't copy pfmemalloc flag in __copy_skb_header()")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Tested-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The pfmemalloc flag indicates that the skb was allocated from
the PFMEMALLOC reserves, and the flag is currently copied on skb
copy and clone.
However, an skb copied from an skb flagged with pfmemalloc
wasn't necessarily allocated from PFMEMALLOC reserves, and on
the other hand an skb allocated that way might be copied from an
skb that wasn't.
So we should not copy the flag on skb copy, and rather decide
whether to allow an skb to be associated with sockets unrelated
to page reclaim depending only on how it was allocated.
Move the pfmemalloc flag before headers_start[0] using an
existing 1-bit hole, so that __copy_skb_header() doesn't copy
it.
When cloning, we'll now take care of this flag explicitly,
contravening to the warning comment of __skb_clone().
While at it, restore the newline usage introduced by commit
b193722731 ("net: reorganize sk_buff for faster
__copy_skb_header()") to visually separate bytes used in
bitfields after headers_start[0], that was gone after commit
a9e419dc7b ("netfilter: merge ctinfo into nfct pointer storage
area"), and describe the pfmemalloc flag in the kernel-doc
structure comment.
This doesn't change the size of sk_buff or cacheline boundaries,
but consolidates the 15 bits hole before tc_index into a 2 bytes
hole before csum, that could now be filled more easily.
Reported-by: Patrick Talbert <ptalbert@redhat.com>
Fixes: c93bdd0e03 ("netvm: allow skb allocation to use PFMEMALLOC reserves")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is done in preparation for the upcoming time based transmission
patchset. Now that skb->tstamp will be used to hold packet's txtime,
we must ensure that it is being cleared when traversing namespaces.
Also, doing that from skb_scrub_packet() before the early return would
break our feature when tunnels are used.
Signed-off-by: Jesus Sanchez-Palencia <jesus.sanchez-palencia@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.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>
alloc_skb_with_frags uses __GFP_NORETRY for non-sleeping allocations
which is just a noop and a little bit confusing.
__GFP_NORETRY was added by ed98df3361 ("net: use __GFP_NORETRY for
high order allocations") to prevent from the OOM killer. Yet this was
not enough because fb05e7a89f ("net: don't wait for order-3 page
allocation") didn't want an excessive reclaim for non-costly orders
so it made it completely NOWAIT while it preserved __GFP_NORETRY in
place which is now redundant.
Drop the pointless __GFP_NORETRY because this function is used as
copy&paste source for other places.
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The sock reference is lost when scrubbing the packet and that breaks
TSQ (TCP Small Queues) and XPS (Transmit Packet Steering) causing
performance impacts of about 50% in a single TCP stream when crossing
network namespaces.
XPS breaks because the queue mapping stored in the socket is not
available, so another random queue might be selected when the stack
needs to transmit something like a TCP ACK, or TCP Retransmissions.
That causes packet re-ordering and/or performance issues.
TSQ breaks because it orphans the packet while it is still in the
host, so packets are queued contributing to the buffer bloat problem.
Preserving the sock reference fixes both issues. The socket is
orphaned anyways in the receiving path before any relevant action
and on TX side the netfilter checks if the reference is local before
use it.
Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Manage pending per-NAPI GRO packets via list_head.
Return an SKB pointer from the GRO receive handlers. When GRO receive
handlers return non-NULL, it means that this SKB needs to be completed
at this time and removed from the NAPI queue.
Several operations are greatly simplified by this transformation,
especially timing out the oldest SKB in the list when gro_count
exceeds MAX_GRO_SKBS, and napi_gro_flush() which walks the queue
in reverse order.
Signed-off-by: David S. Miller <davem@davemloft.net>
copy_skb_header is renamed to skb_copy_header and
exported. Exposing this function give more flexibility
in copying SKBs.
skb_copy and skb_copy_expand do not give enough control
over which parts are copied.
Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: Boris Pismenny <borisp@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement generic segmentation offload support for udp datagrams. A
follow-up patch adds support to the protocol stack to generate such
packets.
UDP GSO is not UFO. UFO fragments a single large datagram. GSO splits
a large payload into a number of discrete UDP datagrams.
The implementation adds a GSO type SKB_UDP_GSO_L4 to differentiate it
from UFO (SKB_UDP_GSO).
IPPROTO_UDPLITE is excluded, as that protocol has no gso handler
registered.
[ Export __udp_gso_segment for ipv6. -DaveM ]
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After working on IP defragmentation lately, I found that some large
packets defeat CHECKSUM_COMPLETE optimization because of NIC adding
zero paddings on the last (small) fragment.
While removing the padding with pskb_trim_rcsum(), we set skb->ip_summed
to CHECKSUM_NONE, forcing a full csum validation, even if all prior
fragments had CHECKSUM_COMPLETE set.
We can instead compute the checksum of the part we are trimming,
usually smaller than the part we keep.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
syzbot reported __skb_try_recv_from_queue() was using skb->peeked
while it was potentially unitialized.
We need to clear it in __skb_clone()
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Minor conflicts in drivers/net/ethernet/mellanox/mlx5/core/en_rep.c,
we had some overlapping changes:
1) In 'net' MLX5E_PARAMS_LOG_{SQ,RQ}_SIZE -->
MLX5E_REP_PARAMS_LOG_{SQ,RQ}_SIZE
2) In 'net-next' params->log_rq_size is renamed to be
params->log_rq_mtu_frames.
3) In 'net-next' params->hard_mtu is added.
Signed-off-by: David S. Miller <davem@davemloft.net>
Fun set of conflict resolutions here...
For the mac80211 stuff, these were fortunately just parallel
adds. Trivially resolved.
In drivers/net/phy/phy.c we had a bug fix in 'net' that moved the
function phy_disable_interrupts() earlier in the file, whilst in
'net-next' the phy_error() call from this function was removed.
In net/ipv4/xfrm4_policy.c, David Ahern's changes to remove the
'rt_table_id' member of rtable collided with a bug fix in 'net' that
added a new struct member "rt_mtu_locked" which needs to be copied
over here.
The mlxsw driver conflict consisted of net-next separating
the span code and definitions into separate files, whilst
a 'net' bug fix made some changes to that moved code.
The mlx5 infiniband conflict resolution was quite non-trivial,
the RDMA tree's merge commit was used as a guide here, and
here are their notes:
====================
Due to bug fixes found by the syzkaller bot and taken into the for-rc
branch after development for the 4.17 merge window had already started
being taken into the for-next branch, there were fairly non-trivial
merge issues that would need to be resolved between the for-rc branch
and the for-next branch. This merge resolves those conflicts and
provides a unified base upon which ongoing development for 4.17 can
be based.
Conflicts:
drivers/infiniband/hw/mlx5/main.c - Commit 42cea83f95
(IB/mlx5: Fix cleanup order on unload) added to for-rc and
commit b5ca15ad7e (IB/mlx5: Add proper representors support)
add as part of the devel cycle both needed to modify the
init/de-init functions used by mlx5. To support the new
representors, the new functions added by the cleanup patch
needed to be made non-static, and the init/de-init list
added by the representors patch needed to be modified to
match the init/de-init list changes made by the cleanup
patch.
Updates:
drivers/infiniband/hw/mlx5/mlx5_ib.h - Update function
prototypes added by representors patch to reflect new function
names as changed by cleanup patch
drivers/infiniband/hw/mlx5/ib_rep.c - Update init/de-init
stage list to match new order from cleanup patch
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
When errors are enqueued to the error queue via sock_queue_err_skb()
function, it is possible that the waiting application is not notified.
Calling 'sk->sk_data_ready()' would not notify applications that
selected only POLLERR events in poll() (for example).
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Reported-by: Randy E. Witt <randy.e.witt@intel.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When we have a bridge with vlan_filtering on and a vlan device on top of
it, packets would be corrupted in skb_vlan_untag() called from
br_dev_xmit().
The problem sits in skb_reorder_vlan_header() used in skb_vlan_untag(),
which makes use of skb->mac_len. In this function mac_len is meant for
handling rx path with vlan devices with reorder_header disabled, but in
tx path mac_len is typically 0 and cannot be used, which is the problem
in this case.
The current code even does not properly handle rx path (skb_vlan_untag()
called from __netif_receive_skb_core()) with reorder_header off actually.
In rx path single tag case, it works as follows:
- Before skb_reorder_vlan_header()
mac_header data
v v
+-------------------+-------------+------+----
| ETH | VLAN | ETH |
| ADDRS | TPID | TCI | TYPE |
+-------------------+-------------+------+----
<-------- mac_len --------->
<------------->
to be removed
- After skb_reorder_vlan_header()
mac_header data
v v
+-------------------+------+----
| ETH | ETH |
| ADDRS | TYPE |
+-------------------+------+----
<-------- mac_len --------->
This is ok, but in rx double tag case, it corrupts packets:
- Before skb_reorder_vlan_header()
mac_header data
v v
+-------------------+-------------+-------------+------+----
| ETH | VLAN | VLAN | ETH |
| ADDRS | TPID | TCI | TPID | TCI | TYPE |
+-------------------+-------------+-------------+------+----
<--------------- mac_len ---------------->
<------------->
should be removed
<--------------------------->
actually will be removed
- After skb_reorder_vlan_header()
mac_header data
v v
+-------------------+------+----
| ETH | ETH |
| ADDRS | TYPE |
+-------------------+------+----
<--------------- mac_len ---------------->
So, two of vlan tags are both removed while only inner one should be
removed and mac_header (and mac_len) is broken.
skb_vlan_untag() is meant for removing the vlan header at (skb->data - 2),
so use skb->data and skb->mac_header to calculate the right offset.
Reported-by: Brandon Carpenter <brandon.carpenter@cypherpath.com>
Fixes: a6e18ff111 ("vlan: Fix untag operations of stacked vlans with REORDER_HEADER off")
Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Signed-off-by: David S. Miller <davem@davemloft.net>
As well as the basic conversion, I noticed that a lot of the
SCTP code checks gso_type without first checking skb_is_gso()
so I have added that where appropriate.
Also, document the helper.
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
All of the conflicts were cases of overlapping changes.
In net/core/devlink.c, we have to make care that the
resouce size_params have become a struct member rather
than a pointer to such an object.
Signed-off-by: David S. Miller <davem@davemloft.net>
They're very hard to use properly as they do not consider the
GSO_BY_FRAGS case. Code should use skb_gso_validate_network_len
and skb_gso_validate_mac_len as they do consider this case.
Make the seglen functions static, which stops people using them
outside of skbuff.c
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If you take a GSO skb, and split it into packets, will the network
length (L3 headers + L4 headers + payload) of those packets be small
enough to fit within a given MTU?
skb_gso_validate_mtu gives you the answer to that question. However,
we recently added to add a way to validate the MAC length of a split GSO
skb (L2+L3+L4+payload), and the names get confusing, so rename
skb_gso_validate_mtu to skb_gso_validate_network_len
Signed-off-by: Daniel Axtens <dja@axtens.net>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
All kmem caches aren't reallocated once set up.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
RDS would like to use the helper functions for managing pinned pages
added by Commit a91dbff551 ("sock: ulimit on MSG_ZEROCOPY pages")
Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Most callers of put_cmsg() use a "sizeof(foo)" for the length argument.
Within put_cmsg(), a copy_to_user() call is made with a dynamic size, as a
result of the cmsg header calculations. This means that hardened usercopy
will examine the copy, even though it was technically a fixed size and
should be implicitly whitelisted. All the put_cmsg() calls being built
from values in skbuff_head_cache are coming out of the protocol-defined
"cb" field, so whitelist this field entirely instead of creating per-use
bounce buffers, for which there are concerns about performance.
Original report was:
Bad or missing usercopy whitelist? Kernel memory exposure attempt detected from SLAB object 'skbuff_head_cache' (offset 64, size 16)!
WARNING: CPU: 0 PID: 3663 at mm/usercopy.c:81 usercopy_warn+0xdb/0x100 mm/usercopy.c:76
...
__check_heap_object+0x89/0xc0 mm/slab.c:4426
check_heap_object mm/usercopy.c:236 [inline]
__check_object_size+0x272/0x530 mm/usercopy.c:259
check_object_size include/linux/thread_info.h:112 [inline]
check_copy_size include/linux/thread_info.h:143 [inline]
copy_to_user include/linux/uaccess.h:154 [inline]
put_cmsg+0x233/0x3f0 net/core/scm.c:242
sock_recv_errqueue+0x200/0x3e0 net/core/sock.c:2913
packet_recvmsg+0xb2e/0x17a0 net/packet/af_packet.c:3296
sock_recvmsg_nosec net/socket.c:803 [inline]
sock_recvmsg+0xc9/0x110 net/socket.c:810
___sys_recvmsg+0x2a4/0x640 net/socket.c:2179
__sys_recvmmsg+0x2a9/0xaf0 net/socket.c:2287
SYSC_recvmmsg net/socket.c:2368 [inline]
SyS_recvmmsg+0xc4/0x160 net/socket.c:2352
entry_SYSCALL_64_fastpath+0x29/0xa0
Reported-by: syzbot+e2d6cfb305e9f3911dea@syzkaller.appspotmail.com
Fixes: 6d07d1cd30 ("usercopy: Restrict non-usercopy caches to size 0")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If you take a GSO skb, and split it into packets, will the MAC
length (L2 + L3 + L4 headers + payload) of those packets be small
enough to fit within a given length?
Move skb_gso_mac_seglen() to skbuff.h with other related functions
like skb_gso_network_seglen() so we can use it, and then create
skb_gso_validate_mac_len to do the full calculation.
Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
