Re: general protection fault in smc_ioctl (2)

[Eric Dumazet <eric.dumazet@gmail.com>]

On 07/15/2018 06:49 AM, syzbot wrote:
> Hello,
> 
> syzbot found the following crash on:
> 
> HEAD commit:    9cee8c437543 net: mvpp2: mvpp2_cls_flow_get() can be static
> git tree:       net-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=12807b70400000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=89129667b46496c3
> dashboard link: https://syzkaller.appspot.com/bug?extid=35b2c5aa76fd398b9fd4
> compiler:       gcc (GCC) 8.0.1 20180413 (experimental)
> syzkaller repro:https://syzkaller.appspot.com/x/repro.syz?x=14e9cf0c400000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=136325d0400000
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+35b2c5aa76fd398b9fd4@syzkaller.appspotmail.com
> 
> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [#1] SMP KASAN
> CPU: 0 PID: 4516 Comm: syz-executor129 Not tainted 4.18.0-rc3+ #121
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> RIP: 0010:smc_ioctl+0x846/0xd00 net/smc/af_smc.c:1748
> Code: 48 c1 e9 03 80 3c 11 00 0f 85 29 04 00 00 4d 8b b6 a0 04 00 00 48 ba 00 00 00 00 00 fc ff df 49 8d 7e 20 48 89 f9 48 c1 e9 03 <0f> b6 14 11 84 d2 74 09 80 fa 03 0f 8e 65 03 00 00 48 8d 7b 02 41
> RSP: 0018:ffff8801b258f750 EFLAGS: 00010202
> RAX: ffff8801b258f7c8 RBX: ffff8801b258f788 RCX: 0000000000000004
> RDX: dffffc0000000000 RSI: 1ffff100364b1ef9 RDI: 0000000000000020
> RBP: ffff8801b258f9b0 R08: ffffed00364b1efa R09: ffffed00364b1ef9
> R10: ffffed00364b1ef9 R11: ffff8801b258f7cf R12: 1ffff100364b1eed
> R13: 0000000020000040 R14: 0000000000000000 R15: 1ffff100364b1f11
> FS:  00007fdddb23c700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fdddb21ae78 CR3: 00000001b6c9a000 CR4: 00000000001406f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  sock_do_ioctl+0xe4/0x3e0 net/socket.c:969
>  sock_ioctl+0x30d/0x680 net/socket.c:1093
>  vfs_ioctl fs/ioctl.c:46 [inline]
>  file_ioctl fs/ioctl.c:500 [inline]
>  do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:684
>  ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
>  __do_sys_ioctl fs/ioctl.c:708 [inline]
>  __se_sys_ioctl fs/ioctl.c:706 [inline]
>  __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
>  do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
>  entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x445e89
> Code: e8 7c e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 eb 0c fc ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007fdddb23bdb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 00000000006dbc3c RCX: 0000000000445e89
> RDX: 0000000020000040 RSI: 0000000000008905 RDI: 000000000000006d
> RBP: 00000000006dbc38 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 00007ffe54550fbf R14: 00007fdddb23c9c0 R15: 0000000000000004
> Modules linked in:
> Dumping ftrace buffer:
>    (ftrace buffer empty)
> ---[ end trace 924422afa249de86 ]---
> RIP: 0010:smc_ioctl+0x846/0xd00 net/smc/af_smc.c:1748
> Code: 48 c1 e9 03 80 3c 11 00 0f 85 29 04 00 00 4d 8b b6 a0 04 00 00 48 ba 00 00 00 00 00 fc ff df 49 8d 7e 20 48 89 f9 48 c1 e9 03 <0f> b6 14 11 84 d2 74 09 80 fa 03 0f 8e 65 03 00 00 48 8d 7b 02 41
> RSP: 0018:ffff8801b258f750 EFLAGS: 00010202
> RAX: ffff8801b258f7c8 RBX: ffff8801b258f788 RCX: 0000000000000004
> RDX: dffffc0000000000 RSI: 1ffff100364b1ef9 RDI: 0000000000000020
> RBP: ffff8801b258f9b0 R08: ffffed00364b1efa R09: ffffed00364b1ef9
> R10: ffffed00364b1ef9 R11: ffff8801b258f7cf R12: 1ffff100364b1eed
> R13: 0000000020000040 R14: 0000000000000000 R15: 1ffff100364b1f11
> FS:  00007fdddb23c700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fdddb21ae78 CR3: 00000001b6c9a000 CR4: 00000000001406f0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> 
> 
> ---
> This bug is generated by a bot. It may contain errors.
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> 
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Probably caused by commit de8474eb9d50fd47b8c73816f34739dec5e96754
("net/smc: urgent data support")