general protection fault in rdma_listen

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 78d697fc Linux 4.14.172
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=16161039e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=31ad682bcda9b93f
dashboard link: https://syzkaller.appspot.com/bug?extid=cea863a7d8c0caec7b5f
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+cea863...@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] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 32696 Comm: syz-executor.4 Not tainted 4.14.172-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8880471b66c0 task.stack: ffff88803f7d8000
RIP: 0010:cma_bind_listen drivers/infiniband/core/cma.c:3186 [inline]
RIP: 0010:rdma_listen+0x281/0x800 drivers/infiniband/core/cma.c:3299
RSP: 0018:ffff88803f7dfbf0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 1ffff11007efbf86 RCX: 0000000000000000
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000008
RBP: ffff888051f7a000 R08: dffffc0000000000 R09: ffffffff8a099a68
R10: ffff88803f7dfbf0 R11: ffff8880471b66c0 R12: 0000000000000000
R13: 0000000000000400 R14: ffff888057ac9a40 R15: 0000000000000008
FS: 00007f3a1116b700(0000) GS:ffff8880aea00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020001000 CR3: 000000008e638000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
ucma_listen+0x10b/0x160 drivers/infiniband/core/ucma.c:1078
ucma_write+0x206/0x2c0 drivers/infiniband/core/ucma.c:1672
__vfs_write+0xe4/0x630 fs/read_write.c:480
vfs_write+0x192/0x4e0 fs/read_write.c:544
SYSC_write fs/read_write.c:590 [inline]
SyS_write+0xf2/0x210 fs/read_write.c:582
do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45c479
RSP: 002b:00007f3a1116ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f3a1116b6d4 RCX: 000000000045c479
RDX: 0000000000000010 RSI: 0000000020000040 RDI: 0000000000000004
RBP: 000000000076bfc0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000cbe R14: 00000000004cea34 R15: 000000000076bfcc
Code: 4c 8b a5 c0 01 00 00 31 f6 48 c7 c7 60 f1 5a 88 e8 75 a4 9c 01 48 b8 00 00 00 00 00 fc ff df 49 8d 7c 24 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 d8 04 00 00 48 b8 00 00 00 00 00 fc ff df 49
RIP: cma_bind_listen drivers/infiniband/core/cma.c:3186 [inline] RSP: ffff88803f7dfbf0
RIP: rdma_listen+0x281/0x800 drivers/infiniband/core/cma.c:3299 RSP: ffff88803f7dfbf0
---[ end trace d24bd88faf7fe906 ]---


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.