syzbot

 sign-in | mailing list | source | docs
🐞 Open [984] ≡ Subsystems 🐞 Fixed [5216] 🐞 Invalid [12476] ⬇ Missing Backports [82] 📈 Kernel Health 📈 Bug Lifetimes 📈 Fuzzing 📈 Crashes 💬 Send us feedback

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: 1334d, last: 1324d
Cause bisection: introduced by (bisect log) :
commit a9ed4a6560b8562b7e2e2bed9527e88001f7b682
Author: Marc Zyngier <maz@kernel.org>
Date: Wed Aug 19 16:12:17 2020 +0000

  epoll: Keep a reference on files added to the check list

Crash: WARNING: ODEBUG bug in exit_to_user_mode_prepare (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
commit 9c516e0e4554e8f26ab73d46cbc789d7d8db664d
Author: Brian Foster <bfoster@redhat.com>
Date: Tue Aug 18 15:05:58 2020 +0000

  xfs: finish dfops on every insert range shift iteration

  
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
WARNING: ODEBUG bug in exit_to_user_mode_prepare 1 (3) 2020/11/11 11:18
▶ ▼ Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING: ODEBUG bug in exit_to_user_mode_prepare (2) kernel 1 358d 357d 0/26 closed as dup on 2023/05/29 14:49

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..

Crashes (27):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/08/31 11:35 upstream dcc5c6f013d8 d5a3ae1f .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/08/31 09:01 upstream dcc5c6f013d8 d5a3ae1f .config console log report syz C ci-upstream-kasan-gce-smack-root
2020/08/25 19:37 upstream 6a9dc5fd6170 344da168 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/08/25 14:39 upstream 6a9dc5fd6170 344da168 .config console log report syz C ci-upstream-kasan-gce-smack-root
2020/08/25 14:36 upstream 6a9dc5fd6170 344da168 .config console log report syz C ci-upstream-kasan-gce-root
2020/08/24 18:07 upstream d012a7190fc1 67b599d1 .config console log report syz C ci-upstream-kasan-gce-root
2020/08/24 15:26 upstream d012a7190fc1 67b599d1 .config console log report syz C ci-upstream-kasan-gce-root
2020/08/24 15:25 upstream d012a7190fc1 67b599d1 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/08/24 15:04 upstream d012a7190fc1 67b599d1 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/09/02 22:09 upstream 9c7d619be5a0 abf9ba4f .config console log report syz C ci-upstream-kasan-gce-386
2020/08/30 06:13 net-old c8146fe292a7 d5a3ae1f .config console log report syz C ci-upstream-net-this-kasan-gce
2020/08/28 16:32 net-old b43c75abfd08 816e0689 .config console log report syz C ci-upstream-net-this-kasan-gce
2020/08/28 00:26 net-old af8ea1111346 816e0689 .config console log report syz C ci-upstream-net-this-kasan-gce
2020/09/03 09:27 net-next-old d3dfc362e073 abf9ba4f .config console log report syz C ci-upstream-net-kasan-gce
2020/08/30 06:28 net-next-old 0f091e43310f d5a3ae1f .config console log report syz C ci-upstream-net-kasan-gce
2020/08/28 12:07 net-next-old 50aba46c234e 816e0689 .config console log report syz C ci-upstream-net-kasan-gce
2020/09/01 03:15 linux-next b36c969764ab d5a3ae1f .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2020/09/02 08:44 upstream b765a32a2e91 abf9ba4f .config console log report syz ci-upstream-kasan-gce-smack-root
2020/08/29 23:07 upstream 4d41ead6ead9 d5a3ae1f .config console log report syz ci-upstream-kasan-gce-smack-root
2020/08/29 10:17 upstream 96d454cd2c16 d5a3ae1f .config console log report syz ci-upstream-kasan-gce-root
2020/08/29 09:59 upstream 96d454cd2c16 d5a3ae1f .config console log report syz ci-upstream-kasan-gce
2020/08/24 20:28 upstream d012a7190fc1 67b599d1 .config console log report syz ci-upstream-kasan-gce-smack-root
2020/08/28 23:02 upstream 15bc20c6af4c d5a3ae1f .config console log report syz ci-upstream-kasan-gce-386
2020/08/28 10:41 net-next-old 50aba46c234e 816e0689 .config console log report syz ci-upstream-net-kasan-gce
2020/08/30 02:03 linux-next b36c969764ab d5a3ae1f .config console log report syz ci-upstream-linux-next-kasan-gce-root
2020/08/30 03:30 upstream 1127b219ce94 d5a3ae1f .config console log report ci-upstream-kasan-gce-smack-root
2020/08/28 10:36 linux-next b36c969764ab 816e0689 .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.