INFO: task hung in synchronize_rcu

Status: upstream: reported C repro on 2019/11/08 21:27
Reported-by: syzbot+2911186fc91302d7feac@syzkaller.appspotmail.com
First crash: 2456d, last: 1265d
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Similar bugs (15)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in synchronize_rcu (3) 1 syz, C done done 374 1262d 2199d 22/29 fixed on 2023/02/24 13:50
linux-6.1 INFO: task hung in synchronize_rcu origin:lts-only 1 syz, C unreliable 56 23d 1217d 0/3 upstream: reported C repro on 2023/04/01 04:49
android-6-12 INFO: task hung in synchronize_rcu (3) 1 2 8d16h 20d 0/1 premoderation: reported on 2026/07/10 14:29
android-49 INFO: task hung in synchronize_rcu 1 1 2435d 2435d 0/3 auto-closed as invalid on 2020/03/28 16:57
linux-4.14 INFO: task hung in synchronize_rcu vfs 1 syz, C error 162 1276d 2458d 0/1 upstream: reported C repro on 2019/11/07 04:32
linux-5.15 INFO: task hung in synchronize_rcu 1 1 1202d 1202d 0/3 auto-obsoleted due to no activity on 2023/08/14 02:05
android-6-12 INFO: task hung in synchronize_rcu 1 41 260d 384d 0/1 auto-obsoleted due to no activity on 2026/01/01 15:51
linux-5.15 INFO: task hung in synchronize_rcu (3) origin:lts-only 1 syz, C error 56 6d23h 735d 0/3 upstream: reported C repro on 2024/07/26 03:55
upstream INFO: task hung in synchronize_rcu 1 syz done 1206 2435d 2462d 14/29 fixed on 2019/11/29 15:48
upstream INFO: task hung in synchronize_rcu (4) prio:high fs net 1 syz, C done error 4181 2h20m 1184d 0/29 upstream: reported C repro on 2023/05/04 02:01
linux-5.15 INFO: task hung in synchronize_rcu (2) 1 1 890d 890d 0/3 auto-obsoleted due to no activity on 2024/05/31 13:53
android-414 INFO: task hung in synchronize_rcu 1 1 2453d 2453d 0/1 auto-closed as invalid on 2020/03/10 10:42
upstream INFO: task hung in synchronize_rcu (2) trace 1 8 2434d 2435d 0/29 closed as invalid on 2019/11/30 16:54
linux-6.6 INFO: task hung in synchronize_rcu 1 9 4d22h 273d 0/2 upstream: reported on 2025/10/30 17:16
android-6-12 INFO: task hung in synchronize_rcu (2) 1 5 125d 166d 0/1 auto-obsoleted due to no activity on 2026/06/25 10:28

Sample crash report:
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
INFO: task syz-executor305:8241 blocked for more than 140 seconds.
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
      Not tainted 4.19.211-syzkaller #0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
syz-executor305 D28648  8241   8104 0x00000004
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
Call Trace:
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 exp_funnel_lock kernel/rcu/tree_exp.h:320 [inline]
 _synchronize_rcu_expedited+0x60c/0x6f0 kernel/rcu/tree_exp.h:667
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 synchronize_rcu_bh_expedited include/linux/rcutree.h:71 [inline]
 synchronize_rcu_bh+0xc1/0x160 kernel/rcu/tree.c:3193
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 vhost_net_release+0x13d/0x210 drivers/vhost/net.c:1178
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 __fput+0x2ce/0x890 fs/file_table.c:278
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 task_work_run+0x148/0x1c0 kernel/task_work.c:113
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 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
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RIP: 0033:0x7f0b55b9b793
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
Code: Bad RIP value.
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RSP: 002b:00007fff65c9ae98 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007f0b55b9b793
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RDX: 0000000000000000 RSI: 0000000020001880 RDI: 0000000000000004
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
R10: 0000000004000004 R11: 0000000000000246 R12: 00007fff65c9aed0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
R13: 00007fff65c9aec0 R14: 00007fff65c9aeb0 R15: 0000000000000000
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
INFO: task syz-executor305:8242 blocked for more than 140 seconds.
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
      Not tainted 4.19.211-syzkaller #0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
syz-executor305 D28648  8242   8107 0x00000004
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
Call Trace:
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 exp_funnel_lock kernel/rcu/tree_exp.h:320 [inline]
 _synchronize_rcu_expedited+0x60c/0x6f0 kernel/rcu/tree_exp.h:667
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 synchronize_rcu_bh_expedited include/linux/rcutree.h:71 [inline]
 synchronize_rcu_bh+0xc1/0x160 kernel/rcu/tree.c:3193
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 vhost_net_release+0x13d/0x210 drivers/vhost/net.c:1178
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 __fput+0x2ce/0x890 fs/file_table.c:278
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 task_work_run+0x148/0x1c0 kernel/task_work.c:113
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 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
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RIP: 0033:0x7f0b55b9b793
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
Code: Bad RIP value.
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RSP: 002b:00007fff65c9ae98 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007f0b55b9b793
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RDX: 0000000000000000 RSI: 0000000020001880 RDI: 0000000000000004
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
R10: 0000000004000004 R11: 0000000000000246 R12: 00007fff65c9aed0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
R13: 00007fff65c9aec0 R14: 00007fff65c9aeb0 R15: 0000000000000000
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
INFO: task syz-executor305:8243 blocked for more than 140 seconds.
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
      Not tainted 4.19.211-syzkaller #0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
syz-executor305 D28648  8243   8109 0x00000004
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
Call Trace:
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 exp_funnel_lock kernel/rcu/tree_exp.h:320 [inline]
 _synchronize_rcu_expedited+0x60c/0x6f0 kernel/rcu/tree_exp.h:667
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 synchronize_rcu_bh_expedited include/linux/rcutree.h:71 [inline]
 synchronize_rcu_bh+0xc1/0x160 kernel/rcu/tree.c:3193
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 vhost_net_release+0x13d/0x210 drivers/vhost/net.c:1178
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 __fput+0x2ce/0x890 fs/file_table.c:278
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 task_work_run+0x148/0x1c0 kernel/task_work.c:113
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x251/0x2a0 arch/x86/entry/common.c:167
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 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
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RIP: 0033:0x7f0b55b9b793
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
Code: Bad RIP value.
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RSP: 002b:00007fff65c9ae98 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007f0b55b9b793
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RDX: 0000000000000000 RSI: 0000000020001880 RDI: 0000000000000004
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
R10: 0000000004000004 R11: 0000000000000246 R12: 00007fff65c9aed0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
R13: 00007fff65c9aec0 R14: 00007fff65c9aeb0 R15: 0000000000000000
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0

Showing all locks held in the system:
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
1 lock held by khungtaskd/1570:
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 #0: 000000003458d367 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
6 locks held by kworker/1:2/3460:
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
1 lock held by in:imklog/7798:
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
1 lock held by syz-executor305/8231:
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 #0: 00000000dd4d0d64 (rcu_sched_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline]
 #0: 00000000dd4d0d64 (rcu_sched_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x256/0x6f0 kernel/rcu/tree_exp.h:667
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
1 lock held by syz-executor305/8264:
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 #0: 00000000dd4d0d64 (rcu_sched_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:329 [inline]
 #0: 00000000dd4d0d64 (rcu_sched_state.exp_mutex){+.+.}, at: _synchronize_rcu_expedited+0x256/0x6f0 kernel/rcu/tree_exp.h:667
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0

hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
=============================================

hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
NMI backtrace for cpu 0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
CPU: 0 PID: 1570 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x991/0xe60 kernel/hung_task.c:287
 kthread+0x33f/0x460 kernel/kthread.c:259
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
Sending NMI from CPU 0 to CPUs 1:
hid-generic 0009:0000:FFFFFFC0.0006: unknown main item tag 0x0
NMI backtrace for cpu 1
CPU: 1 PID: 3460 Comm: kworker/1:2 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Workqueue: events uhid_device_add_worker
RIP: 0010:number+0x46c/0xa90 lib/vsprintf.c:505
Code: e0 4c 89 e2 48 be 00 00 00 00 00 fc ff df 48 c1 e8 03 83 e2 07 0f b6 04 30 38 d0 7f 08 84 c0 0f 85 fe 05 00 00 41 c6 04 24 20 <e8> ef 80 72 f9 83 eb 01 31 ff 49 83 c4 01 89 de e8 4f 82 72 f9 83
RSP: 0018:ffff8880a9fd7000 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff87f00439
RDX: 0000000000000001 RSI: dffffc0000000000 RDI: 0000000000000005
RBP: 0000000000000002 R08: 0000000000000009 R09: 0000000000000000
R10: 0000000000000005 R11: 0000000000000000 R12: ffffffff8d202321
R13: 0000000000000003 R14: ffffffffffffffff R15: ffffffff8d202321
FS:  0000000000000000(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6a840051b8 CR3: 00000000a194c000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 vsnprintf+0xf07/0x14f0 lib/vsprintf.c:2385
 sprintf+0xc0/0x100 lib/vsprintf.c:2521
 print_time kernel/printk/printk.c:1264 [inline]
 print_prefix+0x265/0x3f0 kernel/printk/printk.c:1287
 msg_print_text+0xcd/0x1c0 kernel/printk/printk.c:1314
 console_unlock+0x321/0x1110 kernel/printk/printk.c:2434
 vprintk_emit+0x2d1/0x740 kernel/printk/printk.c:1965
 dev_vprintk_emit+0x2e3/0x640 drivers/base/core.c:3264
 dev_printk_emit+0xbb/0xf0 drivers/base/core.c:3275
 __dev_printk+0x108/0x260 drivers/base/core.c:3287
 _dev_warn+0xd8/0x110 drivers/base/core.c:3331
 hid_parser_main+0x65d/0xb60 drivers/hid/hid-core.c:629
 hid_open_report+0x355/0x6e0 drivers/hid/hid-core.c:1089
 hid_parse include/linux/hid.h:1032 [inline]
 hid_generic_probe+0x4a/0x90 drivers/hid/hid-generic.c:66
 hid_device_probe+0x29e/0x3d0 drivers/hid/hid-core.c:2105
 really_probe+0x622/0xbd0 drivers/base/dd.c:506
 driver_probe_device+0x218/0x340 drivers/base/dd.c:667
 __device_attach_driver+0x29e/0x370 drivers/base/dd.c:754
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:464
 __device_attach+0x226/0x470 drivers/base/dd.c:822
 bus_probe_device+0x1ea/0x2a0 drivers/base/bus.c:524
 device_add+0xb37/0x16d0 drivers/base/core.c:2170
 hid_add_device+0x344/0x9e0 drivers/hid/hid-core.c:2257
 uhid_device_add_worker+0x3a/0x150 drivers/hid/uhid.c:65
 process_one_work+0x864/0x1570 kernel/workqueue.c:2153
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Crashes (70):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/09/29 09:17 linux-4.19.y 3f8a27f9e27b a41a2080 .config console log report syz C [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in synchronize_rcu
2023/02/11 11:09 linux-4.19.y 3f8a27f9e27b 93e26d60 .config console log report syz [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/11/10 22:24 linux-4.19.y 3f8a27f9e27b 3ead01ad .config console log report syz [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/07/18 19:53 linux-4.19.y 3f8a27f9e27b ff988920 .config console log report syz ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/10/09 20:14 linux-4.19.y 3f8a27f9e27b aea5da89 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/09/29 04:16 linux-4.19.y 3f8a27f9e27b a41a2080 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/09/24 01:12 linux-4.19.y 3f8a27f9e27b 0042f2b4 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/09/20 18:26 linux-4.19.y 3f8a27f9e27b c4b8ccfd .config console log report info [disk image] [vmlinux] ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/08/27 12:17 linux-4.19.y 3f8a27f9e27b 07177916 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/08/16 02:47 linux-4.19.y 3f8a27f9e27b 7a7cb304 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/05/20 06:35 linux-4.19.y 3f8a27f9e27b cb1ac2e7 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/05/13 11:16 linux-4.19.y 3f8a27f9e27b 7ce5a022 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/04/07 10:10 linux-4.19.y 3f8a27f9e27b 53c67432 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/04/02 04:06 linux-4.19.y 3f8a27f9e27b 79a2a8fc .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/03/22 04:13 linux-4.19.y 3f8a27f9e27b e2d91b1d .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/02/26 11:46 linux-4.19.y 3f8a27f9e27b 45a13a73 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/02/15 12:36 linux-4.19.y 3f8a27f9e27b 8b9ca619 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/02/10 21:05 linux-4.19.y 3f8a27f9e27b 0b33604d .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/02/08 16:57 linux-4.19.y 3f8a27f9e27b 0b33604d .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/01/16 09:53 linux-4.19.y 3f8a27f9e27b 723cfaf0 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/01/14 07:48 linux-4.19.y 3f8a27f9e27b b8d780ab .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/01/13 01:44 linux-4.19.y 3f8a27f9e27b 44d1319a .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/01/12 22:50 linux-4.19.y 3f8a27f9e27b 44d1319a .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/01/12 20:36 linux-4.19.y 3f8a27f9e27b 44d1319a .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/01/12 15:06 linux-4.19.y 3f8a27f9e27b 44d1319a .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/01/11 05:23 linux-4.19.y 3f8a27f9e27b ddb0ab8c .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/01/10 09:25 linux-4.19.y 3f8a27f9e27b 2ca0d385 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/01/09 06:14 linux-4.19.y 3f8a27f9e27b 2ca0d385 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/01/09 02:46 linux-4.19.y 3f8a27f9e27b 2ca0d385 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2022/01/07 11:48 linux-4.19.y 3f8a27f9e27b 6acc789a .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/12/30 02:24 linux-4.19.y 3f8a27f9e27b 6cc879d4 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/12/25 22:30 linux-4.19.y 3f8a27f9e27b 6caa12e4 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/12/24 14:55 linux-4.19.y 3f8a27f9e27b 6caa12e4 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/12/24 08:58 linux-4.19.y 3f8a27f9e27b 6caa12e4 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/12/24 05:05 linux-4.19.y 3f8a27f9e27b 6caa12e4 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/12/23 20:09 linux-4.19.y 3f8a27f9e27b 6caa12e4 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/12/21 14:27 linux-4.19.y 3f8a27f9e27b a938f0b8 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/12/19 13:59 linux-4.19.y 3f8a27f9e27b 44068e19 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/12/10 19:53 linux-4.19.y 3f8a27f9e27b fc17c959 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/11/30 02:47 linux-4.19.y 3f8a27f9e27b d0830353 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/11/29 02:06 linux-4.19.y 3f8a27f9e27b 63eeac02 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/11/03 06:02 linux-4.19.y 3f8a27f9e27b 17f3edd2 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/10/25 08:19 linux-4.19.y 3f8a27f9e27b 4f0000ee .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/10/03 12:50 linux-4.19.y c2276d585654 db0f5787 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/09/15 16:43 linux-4.19.y b172b44fcb17 07e953c1 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/08/19 08:55 linux-4.19.y 59456c9cc40c a2fe1cb5 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/06/22 02:31 linux-4.19.y eb575cd5d7f6 aba2b2fb .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/06/13 09:07 linux-4.19.y 9a2dc0e6c531 1ba81399 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/06/06 21:47 linux-4.19.y 1722257b8ece 500c2339 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/05/09 15:48 linux-4.19.y 3c8c23092588 bc5434be .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/04/19 02:08 linux-4.19.y 2965db2e004c 7e2b734b .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/03/11 13:59 linux-4.19.y 030194a5b292 c2ca1f2a .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/03/05 01:53 linux-4.19.y dfb571610ba3 f89ed068 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/02/24 07:03 linux-4.19.y 2d19be4653f5 fcc6d71b .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/02/07 12:06 linux-4.19.y 811218eceeaa 2ce644fc .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/02/03 23:12 linux-4.19.y 811218eceeaa 624dad51 .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/02/01 11:17 linux-4.19.y 811218eceeaa fc9fd31e .config console log report info ci2-linux-4-19 INFO: task hung in synchronize_rcu
2021/01/09 06:20 linux-4.19.y 4143d798313f c104d4a3 .config console log report info ci2-linux-4-19
2021/01/05 22:37 linux-4.19.y 3207316b3bee b1c228e1 .config console log report info ci2-linux-4-19
2020/10/15 05:09 linux-4.19.y a1b977b49b66 fc7735a2 .config console log report info ci2-linux-4-19
2020/10/02 15:04 linux-4.19.y b09c34517e1a 062c9832 .config console log report info ci2-linux-4-19
2020/08/07 09:10 linux-4.19.y 961f830af065 cb436c69 .config console log report ci2-linux-4-19
2020/05/10 03:19 linux-4.19.y 84920cc7fbe1 8742a2b9 .config console log report ci2-linux-4-19
2020/02/20 18:48 linux-4.19.y 4fccc2503536 81230308 .config console log report ci2-linux-4-19
2020/01/19 05:25 linux-4.19.y dc4ba5be1bab bc8bc756 .config console log report ci2-linux-4-19
2020/01/16 02:28 linux-4.19.y db5b9190ff82 f9b69507 .config console log report ci2-linux-4-19
2019/12/30 11:25 linux-4.19.y 672481c2deff af6b8ef8 .config console log report ci2-linux-4-19
2019/12/14 10:56 linux-4.19.y 312017a460d5 eef6e580 .config console log report ci2-linux-4-19
2019/12/05 23:21 linux-4.19.y fb683b5e3f53 9fd5a512 .config console log report ci2-linux-4-19
2019/11/08 20:26 linux-4.19.y 5ee93551c703 1e35461e .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.