Hello,
syzbot found the following crash on:
HEAD commit: fb683b5e Linux 4.19.88
git tree: linux-4.19.y
console output:
https://syzkaller.appspot.com/x/log.txt?x=12a4ae41e00000
kernel config:
https://syzkaller.appspot.com/x/.config?x=aa0c39a6a0078b1c
dashboard link:
https://syzkaller.appspot.com/bug?extid=66f836eb7f735883cb17
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+66f836...@syzkaller.appspotmail.com
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=8
sclass=netlink_route_socket pig=17304 comm=syz-executor.3
SELinux: unrecognized netlink message: protocol=0 nlmsg_type=8
sclass=netlink_route_socket pig=17331 comm=syz-executor.3
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: 17311 Comm: syz-executor.1 Not tainted 4.19.88-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:cdev_del+0x28/0xa0 fs/char_dev.c:602
Code: 00 00 55 48 89 e5 41 54 49 89 fc 48 83 ec 08 e8 4e c6 bd ff 49 8d 7c
24 64 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48
89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 55 49
RSP: 0018:ffff8880a5b8f9b0 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff8880a45d5600 RCX: ffffc9000862d000
RDX: 000000000000000c RSI: ffffffff81ad7cf2 RDI: 0000000000000064
RBP: ffff8880a5b8f9c0 R08: ffff888053214540 R09: ffff888053214e08
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000008 R14: ffff8880a405e088 R15: ffff888083c8a5a8
FS: 00007f61e7b77700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8d6f0cb000 CR3: 0000000095a8c000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
tty_unregister_device drivers/tty/tty_io.c:3049 [inline]
tty_unregister_device+0x117/0x1b0 drivers/tty/tty_io.c:3044
gsmld_detach_gsm drivers/tty/n_gsm.c:2285 [inline]
gsmld_close+0xb2/0x188 drivers/tty/n_gsm.c:2354
tty_ldisc_close.isra.0+0xaf/0xe0 drivers/tty/tty_ldisc.c:486
tty_ldisc_kill+0x4b/0xc0 drivers/tty/tty_ldisc.c:632
tty_ldisc_release+0xc6/0x280 drivers/tty/tty_ldisc.c:799
tty_release_struct+0x1b/0x50 drivers/tty/tty_io.c:1611
tty_release+0xbcb/0xe90 drivers/tty/tty_io.c:1784
__fput+0x2dd/0x8b0 fs/file_table.c:278
____fput+0x16/0x20 fs/file_table.c:309
task_work_run+0x145/0x1c0 kernel/task_work.c:113
get_signal+0x1baa/0x1fc0 kernel/signal.c:2389
do_signal+0x95/0x1960 arch/x86/kernel/signal.c:821
exit_to_usermode_loop+0x244/0x2c0 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+0x53d/0x620 arch/x86/entry/common.c:296
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a6f9
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f61e7b76c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000000 RBX: 00007f61e7b76c90 RCX: 000000000045a6f9
RDX: 0000000020000000 RSI: 0000000000005423 RDI: 0000000000000007
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f61e7b776d4
R13: 00000000004c5b94 R14: 00000000004dbec8 R15: 0000000000000008
Modules linked in:
---[ end trace 583a212aa1e962e4 ]---
RIP: 0010:cdev_del+0x28/0xa0 fs/char_dev.c:602
Code: 00 00 55 48 89 e5 41 54 49 89 fc 48 83 ec 08 e8 4e c6 bd ff 49 8d 7c
24 64 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48
89 f8 83 e0 07 83 c0 03 38 d0 7c 04 84 d2 75 55 49
RSP: 0018:ffff8880a5b8f9b0 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffff8880a45d5600 RCX: ffffc9000862d000
RDX: 000000000000000c RSI: ffffffff81ad7cf2 RDI: 0000000000000064
RBP: ffff8880a5b8f9c0 R08: ffff888053214540 R09: ffff888053214e08
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000008 R14: ffff8880a405e088 R15: ffff888083c8a5a8
FS: 00007f61e7b77700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8d6f0cb000 CR3: 0000000095a8c000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400