• Vegard Nossum's avatar
    tipc: fix NULL pointer dereference in shutdown() · d2fbdf76
    Vegard Nossum authored
    tipc_msg_create() can return a NULL skb and if so, we shouldn't try to
    call tipc_node_xmit_skb() on it.
    
        general protection fault: 0000 [#1] PREEMPT SMP KASAN
        CPU: 3 PID: 30298 Comm: trinity-c0 Not tainted 4.7.0-rc7+ #19
        Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
        task: ffff8800baf09980 ti: ffff8800595b8000 task.ti: ffff8800595b8000
        RIP: 0010:[<ffffffff830bb46b>]  [<ffffffff830bb46b>] tipc_node_xmit_skb+0x6b/0x140
        RSP: 0018:ffff8800595bfce8  EFLAGS: 00010246
        RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000003023b0e0
        RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffffffff83d12580
        RBP: ffff8800595bfd78 R08: ffffed000b2b7f32 R09: 0000000000000000
        R10: fffffbfff0759725 R11: 0000000000000000 R12: 1ffff1000b2b7f9f
        R13: ffff8800595bfd58 R14: ffffffff83d12580 R15: dffffc0000000000
        FS:  00007fcdde242700(0000) GS:ffff88011af80000(0000) knlGS:0000000000000000
        CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
        CR2: 00007fcddde1db10 CR3: 000000006874b000 CR4: 00000000000006e0
        DR0: 00007fcdde248000 DR1: 00007fcddd73d000 DR2: 00007fcdde248000
        DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000090602
        Stack:
         0000000000000018 0000000000000018 0000000041b58ab3 ffffffff83954208
         ffffffff830bb400 ffff8800595bfd30 ffffffff8309d767 0000000000000018
         0000000000000018 ffff8800595bfd78 ffffffff8309da1a 00000000810ee611
        Call Trace:
         [<ffffffff830c84a3>] tipc_shutdown+0x553/0x880
         [<ffffffff825b4a3b>] SyS_shutdown+0x14b/0x170
         [<ffffffff8100334c>] do_syscall_64+0x19c/0x410
         [<ffffffff83295ca5>] entry_SYSCALL64_slow_path+0x25/0x25
        Code: 90 00 b4 0b 83 c7 00 f1 f1 f1 f1 4c 8d 6d e0 c7 40 04 00 00 00 f4 c7 40 08 f3 f3 f3 f3 48 89 d8 48 c1 e8 03 c7 45 b4 00 00 00 00 <80> 3c 30 00 75 78 48 8d 7b 08 49 8d 75 c0 48 b8 00 00 00 00 00
        RIP  [<ffffffff830bb46b>] tipc_node_xmit_skb+0x6b/0x140
         RSP <ffff8800595bfce8>
        ---[ end trace 57b0484e351e71f1 ]---
    
    I feel like we should maybe return -ENOMEM or -ENOBUFS, but I'm not sure
    userspace is equipped to handle that. Anyway, this is better than a GPF
    and looks somewhat consistent with other tipc_msg_create() callers.
    Signed-off-by: default avatarVegard Nossum <vegard.nossum@oracle.com>
    Acked-by: default avatarYing Xue <ying.xue@windriver.com>
    Acked-by: default avatarJon Maloy <jon.maloy@ericsson.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    d2fbdf76
socket.c 74.2 KB