syzbot
WARNING: ODEBUG bug in exit_to_user_mode_prepare
Status:
fixed on 2020/11/16 12:12
Reported-by: syzbot+fbd7ba7207767ed15165@syzkaller.appspotmail.com
Fix commit:
77f4689de17c
fix regression in "epoll: Keep a reference on files added to the check list"
First crash: 2170d, last: 2160d
Sample crash report:
------------[ cut here ]------------
ODEBUG: free active (active state 1) object type: rcu_head hint: 0x0
WARNING: CPU: 0 PID: 10851 at lib/debugobjects.c:485 debug_print_object+0x160/0x250 lib/debugobjects.c:485
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 10851 Comm: syz-executor984 Not tainted 5.9.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x198/0x1fd lib/dump_stack.c:118
panic+0x347/0x7c0 kernel/panic.c:231
__warn.cold+0x20/0x46 kernel/panic.c:600
report_bug+0x1bd/0x210 lib/bug.c:198
handle_bug+0x38/0x90 arch/x86/kernel/traps.c:234
exc_invalid_op+0x14/0x40 arch/x86/kernel/traps.c:254
asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:debug_print_object+0x160/0x250 lib/debugobjects.c:485
Code: dd e0 27 94 88 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 bf 00 00 00 48 8b 14 dd e0 27 94 88 48 c7 c7 40 1d 94 88 e8 f2 34 a6 fd <0f> 0b 83 05 43 50 13 07 01 48 83 c4 20 5b 5d 41 5c 41 5d c3 48 89
RSP: 0018:ffffc9000d6dfdc8 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: ffff8880a80d6340 RSI: ffffffff815db9a7 RDI: fffff52001adbfab
RBP: 0000000000000001 R08: 0000000000000001 R09: ffff8880ae620f8b
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff89bd68c0
R13: 0000000000000000 R14: dead000000000100 R15: dffffc0000000000
__debug_check_no_obj_freed lib/debugobjects.c:967 [inline]
debug_check_no_obj_freed+0x301/0x41c lib/debugobjects.c:998
kmem_cache_free.part.0+0x151/0x1e0 mm/slab.c:3692
task_work_run+0xdd/0x190 kernel/task_work.c:141
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:140 [inline]
exit_to_user_mode_prepare+0x1e1/0x200 kernel/entry/common.c:167
syscall_exit_to_user_mode+0x7e/0x2e0 kernel/entry/common.c:242
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x446aa9
Code: e8 6c e7 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 5b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f30d6263d88 EFLAGS: 00000246 ORIG_RAX: 00000000000000e9
RAX: 0000000000000000 RBX: 00000000006dbc48 RCX: 0000000000446aa9
RDX: 0000000000000003 RSI: 0000000000000001 RDI: 0000000000000004
RBP: 00000000006dbc40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020001100 R11: 0000000000000246 R12: 00000000006dbc4c
R13: 0000000000000005 R14: 0000000000000004 R15: 00007f30d62646d0
Kernel Offset: disabled
Rebooting in 86400 seconds..
* Struck through repros no longer work on HEAD.