linux/include
Eric Dumazet ceb5d58b21 net: fix sock_wake_async() rcu protection
Dmitry provided a syzkaller (http://github.com/google/syzkaller)
triggering a fault in sock_wake_async() when async IO is requested.

Said program stressed af_unix sockets, but the issue is generic
and should be addressed in core networking stack.

The problem is that by the time sock_wake_async() is called,
we should not access the @flags field of 'struct socket',
as the inode containing this socket might be freed without
further notice, and without RCU grace period.

We already maintain an RCU protected structure, "struct socket_wq"
so moving SOCKWQ_ASYNC_NOSPACE & SOCKWQ_ASYNC_WAITDATA into it
is the safe route.

It also reduces number of cache lines needing dirtying, so might
provide a performance improvement anyway.

In followup patches, we might move remaining flags (SOCK_NOSPACE,
SOCK_PASSCRED, SOCK_PASSSEC) to save 8 bytes and let 'struct socket'
being mostly read and let it being shared between cpus.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-12-01 15:45:05 -05:00
..
acpi Merge branch 'acpi-pci' 2015-11-07 01:30:10 +01:00
asm-generic h8300 update for v4.4 2015-11-12 15:26:39 -08:00
clocksource
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2015-11-05 15:32:38 -08:00
drm Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux 2015-11-10 09:33:06 -08:00
dt-bindings ARM: DT updates for v4.4 2015-11-10 15:06:26 -08:00
keys
kvm s390: A bunch of fixes and optimizations for interrupt and time 2015-11-05 16:26:26 -08:00
linux net: fix sock_wake_async() rcu protection 2015-12-01 15:45:05 -05:00
math-emu
media
memory
misc
net net: fix sock_wake_async() rcu protection 2015-12-01 15:45:05 -05:00
pcmcia
ras
rdma IB/core, cma: Make __attribute_const__ declarations sparse-friendly 2015-10-30 17:57:49 -04:00
rxrpc
scsi scsi: use host wide tags by default 2015-11-09 17:11:57 -08:00
soc ARM: SoC driver updates for v4.4 2015-11-10 15:00:03 -08:00
sound ALSA: Constify ratden/ratnum constraints 2015-10-28 11:42:22 +01:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2015-11-13 20:04:17 -08:00
trace Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2015-11-11 09:03:01 -08:00
uapi VFIO updates for v4.4-rc1 2015-11-13 17:05:32 -08:00
video drm/exynos/decon5433: add support for DECON-TV 2015-11-03 11:46:37 +09:00
xen
Kbuild