2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2025-01-17 10:04:14 +08:00
linux-next/include
Eric Dumazet d654976cbf tcp: fix a potential deadlock in tcp_get_info()
Taking socket spinlock in tcp_get_info() can deadlock, as
inet_diag_dump_icsk() holds the &hashinfo->ehash_locks[i],
while packet processing can use the reverse locking order.

We could avoid this locking for TCP_LISTEN states, but lockdep would
certainly get confused as all TCP sockets share same lockdep classes.

[  523.722504] ======================================================
[  523.728706] [ INFO: possible circular locking dependency detected ]
[  523.734990] 4.1.0-dbg-DEV #1676 Not tainted
[  523.739202] -------------------------------------------------------
[  523.745474] ss/18032 is trying to acquire lock:
[  523.750002]  (slock-AF_INET){+.-...}, at: [<ffffffff81669d44>] tcp_get_info+0x2c4/0x360
[  523.758129]
[  523.758129] but task is already holding lock:
[  523.763968]  (&(&hashinfo->ehash_locks[i])->rlock){+.-...}, at: [<ffffffff816bcb75>] inet_diag_dump_icsk+0x1d5/0x6c0
[  523.774661]
[  523.774661] which lock already depends on the new lock.
[  523.774661]
[  523.782850]
[  523.782850] the existing dependency chain (in reverse order) is:
[  523.790326]
-> #1 (&(&hashinfo->ehash_locks[i])->rlock){+.-...}:
[  523.796599]        [<ffffffff811126bb>] lock_acquire+0xbb/0x270
[  523.802565]        [<ffffffff816f5868>] _raw_spin_lock+0x38/0x50
[  523.808628]        [<ffffffff81665af8>] __inet_hash_nolisten+0x78/0x110
[  523.815273]        [<ffffffff816819db>] tcp_v4_syn_recv_sock+0x24b/0x350
[  523.822067]        [<ffffffff81684d41>] tcp_check_req+0x3c1/0x500
[  523.828199]        [<ffffffff81682d09>] tcp_v4_do_rcv+0x239/0x3d0
[  523.834331]        [<ffffffff816842fe>] tcp_v4_rcv+0xa8e/0xc10
[  523.840202]        [<ffffffff81658fa3>] ip_local_deliver_finish+0x133/0x3e0
[  523.847214]        [<ffffffff81659a9a>] ip_local_deliver+0xaa/0xc0
[  523.853440]        [<ffffffff816593b8>] ip_rcv_finish+0x168/0x5c0
[  523.859624]        [<ffffffff81659db7>] ip_rcv+0x307/0x420

Lets use u64_sync infrastructure instead. As a bonus, 64bit
arches get optimized, as these are nop for them.

Fixes: 0df48c26d8 ("tcp: add tcpi_bytes_acked to tcp_info")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2015-05-22 13:46:06 -04:00
..
acpi ACPICA: remove duplicate u8 typedef 2015-04-28 23:58:54 +02:00
asm-generic TTY/Serial patches for 4.1-rc1 2015-04-21 09:33:10 -07:00
clocksource
crypto Merge git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2015-04-15 10:42:15 -07:00
drm Merge tag 'topic/drm-misc-2015-04-15' of git://anongit.freedesktop.org/drm-intel into drm-next 2015-04-16 08:34:24 +10:00
dt-bindings Merge branch 'for-linus' of git://git.infradead.org/users/vkoul/slave-dma 2015-04-24 09:49:37 -07:00
keys
kvm KVM/ARM changes for v4.1: 2015-04-07 18:09:20 +02:00
linux tcp: fix a potential deadlock in tcp_get_info() 2015-05-22 13:46:06 -04:00
math-emu
media Merge branch 'patchwork' into v4l_for_linus 2015-04-21 06:12:35 -03:00
memory
misc
net inet: properly align icsk_ca_priv 2015-05-19 11:08:00 -04:00
pcmcia
ras
rdma IB/core: Fix unaligned accesses 2015-05-05 13:21:27 -04:00
rxrpc RxRPC: Handle VERSION Rx protocol packets 2015-04-01 16:31:26 +01:00
scsi SCSI: add 1024 max sectors black list flag 2015-04-27 09:38:06 -07:00
soc
sound ASoC: Fixes for v4.1 2015-04-30 19:08:06 +02:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2015-04-24 10:22:09 -07:00
trace Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2015-04-26 17:22:07 -07:00
uapi Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf 2015-05-16 16:40:22 -04:00
video fbdev changes for v4.1 2015-04-20 15:16:25 -07:00
xen xen: Suspend ticks on all CPUs during suspend 2015-04-29 17:10:05 +01:00
Kbuild