• Eric Dumazet's avatar
    sctp: fix possible seqlock seadlock in sctp_packet_transmit() · c5d05276
    Eric Dumazet authored
    [ Upstream commit 757efd32 ]
    
    Dave reported following splat, caused by improper use of
    IP_INC_STATS_BH() in process context.
    
    BUG: using __this_cpu_add() in preemptible [00000000] code: trinity-c117/14551
    caller is __this_cpu_preempt_check+0x13/0x20
    CPU: 3 PID: 14551 Comm: trinity-c117 Not tainted 3.16.0+ #33
     ffffffff9ec898f0 0000000047ea7e23 ffff88022d32f7f0 ffffffff9e7ee207
     0000000000000003 ffff88022d32f818 ffffffff9e397eaa ffff88023ee70b40
     ffff88022d32f970 ffff8801c026d580 ffff88022d32f828 ffffffff9e397ee3
    Call Trace:
     [<ffffffff9e7ee207>] dump_stack+0x4e/0x7a
     [<ffffffff9e397eaa>] check_preemption_disabled+0xfa/0x100
     [<ffffffff9e397ee3>] __this_cpu_preempt_check+0x13/0x20
     [<ffffffffc0839872>] sctp_packet_transmit+0x692/0x710 [sctp]
     [<ffffffffc082a7f2>] sctp_outq_flush+0x2a2/0xc30 [sctp]
     [<ffffffff9e0d985c>] ? mark_held_locks+0x7c/0xb0
     [<ffffffff9e7f8c6d>] ? _raw_spin_unlock_irqrestore+0x5d/0x80
     [<ffffffffc082b99a>] sctp_outq_uncork+0x1a/0x20 [sctp]
     [<ffffffffc081e112>] sctp_cmd_interpreter.isra.23+0x1142/0x13f0 [sctp]
     [<ffffffffc081c86b>] sctp_do_sm+0xdb/0x330 [sctp]
     [<ffffffff9e0b8f1b>] ? preempt_count_sub+0xab/0x100
     [<ffffffffc083b350>] ? sctp_cname+0x70/0x70 [sctp]
     [<ffffffffc08389ca>] sctp_primitive_ASSOCIATE+0x3a/0x50 [sctp]
     [<ffffffffc083358f>] sctp_sendmsg+0x88f/0xe30 [sctp]
     [<ffffffff9e0d673a>] ? lock_release_holdtime.part.28+0x9a/0x160
     [<ffffffff9e0d62ce>] ? put_lock_stats.isra.27+0xe/0x30
     [<ffffffff9e73b624>] inet_sendmsg+0x104/0x220
     [<ffffffff9e73b525>] ? inet_sendmsg+0x5/0x220
     [<ffffffff9e68ac4e>] sock_sendmsg+0x9e/0xe0
     [<ffffffff9e1c0c09>] ? might_fault+0xb9/0xc0
     [<ffffffff9e1c0bae>] ? might_fault+0x5e/0xc0
     [<ffffffff9e68b234>] SYSC_sendto+0x124/0x1c0
     [<ffffffff9e0136b0>] ? syscall_trace_enter+0x250/0x330
     [<ffffffff9e68c3ce>] SyS_sendto+0xe/0x10
     [<ffffffff9e7f9be4>] tracesys+0xdd/0xe2
    
    This is a followup of commits f1d8cba6 ("inet: fix possible
    seqlock deadlocks") and 7f88c6b2 ("ipv6: fix possible seqlock
    deadlock in ip6_finish_output2")
    Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
    Cc: Hannes Frederic Sowa <hannes@stressinduktion.org>
    Reported-by: default avatarDave Jones <davej@redhat.com>
    Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
    Acked-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    c5d05276
output.c 22.2 KB