general protection fault in rose_transmit_link

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 31cc088a Merge tag 'drm-next-2019-07-19' of git://anongit...
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14f5333a600000
kernel config: https://syzkaller.appspot.com/x/.config?x=4dba67bf8b8c9ad7
dashboard link: https://syzkaller.appspot.com/bug?extid=1ccc2ce6125eb3bbe10f
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [da...@davemloft.net linux...@vger.kernel.org
linux-...@vger.kernel.org net...@vger.kernel.org ra...@linux-mips.org
net...@vger.kernel.org]

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+1ccc2c...@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
CPU: 1 PID: 32619 Comm: syz-executor.0 Not tainted 5.2.0+ #67
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:rose_transmit_link+0x32/0x487 net/rose/rose_link.c:263
Code: 41 55 49 89 fd 41 54 49 89 f4 53 48 83 ec 08 e8 a4 a2 0c fb 49 8d 7c
24 32 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48
89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 97 03 00 00
RSP: 0018:ffff8880465afa18 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc90005f65000
RDX: 0000000000000006 RSI: ffffffff8665e23c RDI: 0000000000000032
RBP: ffff8880465afa48 R08: ffff888065552240 R09: ffffed101188722d
R10: ffffed101188722c R11: ffff88808c439163 R12: 0000000000000000
R13: ffff8880a4fb5dc0 R14: 0000000000000013 R15: ffff88808c4390da
FS: 00007fd900ea4700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd12f55050 CR3: 0000000055f8a000 CR4: 00000000001406e0
Call Trace:
rose_write_internal+0x2a7/0x17f0 net/rose/rose_subr.c:198
rose_release+0x1ac/0x450 net/rose/af_rose.c:633
__sock_release+0xce/0x280 net/socket.c:590
sock_close+0x1e/0x30 net/socket.c:1268
__fput+0x2ff/0x890 fs/file_table.c:280
____fput+0x16/0x20 fs/file_table.c:313
task_work_run+0x145/0x1c0 kernel/task_work.c:113
get_signal+0x2078/0x2500 kernel/signal.c:2522
do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815
exit_to_usermode_loop+0x286/0x380 arch/x86/entry/common.c:159
prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
syscall_return_slowpath arch/x86/entry/common.c:274 [inline]
do_syscall_64+0x5a9/0x6a0 arch/x86/entry/common.c:299
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459829
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fd900ea3c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000459829
RDX: 0000000000000040 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fd900ea46d4
R13: 00000000004bfe1a R14: 00000000004d1bd8 R15: 00000000ffffffff
Modules linked in:


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[syzbot]

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