general protection fault in rose_transmit_link

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15718738700000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=6aba34b9ad24e58f6552
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6aba34...@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: 19038 Comm: syz-executor.0 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:rose_transmit_link+0x2e/0x560 net/rose/rose_link.c:266
Code: 41 55 41 54 49 89 fc 55 48 89 f5 53 48 83 ec 08 e8 37 3e 30 fa 48 8d 7d 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 48 04 00 00
RSP: 0018:ffff8880301bfa10 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff888096470d1a RCX: ffffffff8732c6eb
RDX: 0000000000000006 RSI: ffffffff87324739 RDI: 0000000000000032
RBP: 0000000000000000 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000005 R11: 0000000000000000 R12: ffff888047d6d640
R13: 0000000000000010 R14: 0000000000000013 R15: ffff88804705a980
FS: 00007f51b5469700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562408995250 CR3: 000000004e232000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
rose_write_internal+0x272/0x17e0 net/rose/rose_subr.c:201
rose_release+0x146/0x3b0 net/rose/af_rose.c:636
__sock_release+0xcd/0x2a0 net/socket.c:599
sock_close+0x15/0x20 net/socket.c:1214
__fput+0x2ce/0x890 fs/file_table.c:278
task_work_run+0x148/0x1c0 kernel/task_work.c:113
get_signal+0x1b64/0x1f70 kernel/signal.c:2400
do_signal+0x8f/0x1670 arch/x86/kernel/signal.c:799
exit_to_usermode_loop+0x204/0x2a0 arch/x86/entry/common.c:163
prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
do_syscall_64+0x538/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f51b6af4059
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f51b5469168 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: 0000000000000000 RBX: 00007f51b6c06f60 RCX: 00007f51b6af4059
RDX: 0000000000000040 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 00007f51b6b4e08d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdc50e422f R14: 00007f51b5469300 R15: 0000000000022000
Modules linked in:
---[ end trace 4e5ba9d554913f07 ]---
RIP: 0010:rose_transmit_link+0x2e/0x560 net/rose/rose_link.c:266
Code: 41 55 41 54 49 89 fc 55 48 89 f5 53 48 83 ec 08 e8 37 3e 30 fa 48 8d 7d 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 48 04 00 00
RSP: 0018:ffff8880301bfa10 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff888096470d1a RCX: ffffffff8732c6eb
RDX: 0000000000000006 RSI: ffffffff87324739 RDI: 0000000000000032
RBP: 0000000000000000 R08: 0000000000000001 R09: 000000000000001f
R10: 0000000000000005 R11: 0000000000000000 R12: ffff888047d6d640
R13: 0000000000000010 R14: 0000000000000013 R15: ffff88804705a980
FS: 00007f51b5469700(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562408995250 CR3: 000000004e232000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 41 55 push %r13
2: 41 54 push %r12
4: 49 89 fc mov %rdi,%r12
7: 55 push %rbp
8: 48 89 f5 mov %rsi,%rbp
b: 53 push %rbx
c: 48 83 ec 08 sub $0x8,%rsp
10: e8 37 3e 30 fa callq 0xfa303e4c
15: 48 8d 7d 32 lea 0x32(%rbp),%rdi
19: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
20: fc ff df
23: 48 89 fa mov %rdi,%rdx
26: 48 c1 ea 03 shr $0x3,%rdx
* 2a: 0f b6 04 02 movzbl (%rdx,%rax,1),%eax <-- trapping instruction
2e: 48 89 fa mov %rdi,%rdx
31: 83 e2 07 and $0x7,%edx
34: 38 d0 cmp %dl,%al
36: 7f 08 jg 0x40
38: 84 c0 test %al,%al
3a: 0f 85 48 04 00 00 jne 0x488


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[syzbot]

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