INFO: task hung in uhid_char_release

Status: premoderation: reported C repro on 2025/06/19 10:50
Bug presence: origin:upstream
[Documentation on labels]
Reported-by: syzbot+69c758044c075ca3cc58@syzkaller.appspotmail.com
First crash: 484d, last: 11d
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/06/20 lts (merge base) 83b4161a63b8 C [report] INFO: task hung in uevent_show
2025/06/20 upstream (ToT) 75f5f23f8787 C [report] INFO: task hung in uhid_char_release
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: task hung in uhid_char_release origin:lts-only 1 syz, C inconclusive 13 137d 402d 0/2 upstream: reported C repro on 2025/09/09 09:36
upstream INFO: task hung in uhid_char_release input 1 syz, C done done 479 426d 1210d 0/29 upstream: reported C repro on 2023/06/24 03:16
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/09/11 19:01 20m retest repro android16-6.12 report job log log
2026/09/11 19:01 30m retest repro android16-6.12 report job log log
2026/09/11 19:01 18m retest repro android16-6.12 report job log log
2026/09/11 19:01 12m retest repro android16-6.12 report job log log
2026/09/11 19:01 19m retest repro android16-6.12 report job log log
2026/06/19 14:32 12m retest repro android16-6.12 error
2026/06/19 14:32 13m retest repro android16-6.12 error
2026/06/19 14:32 10m retest repro android16-6.12 error
2026/05/30 17:42 18m retest repro android16-6.12 log
2026/05/30 17:42 18m retest repro android16-6.12 log

Sample crash report:
INFO: task syz-executor424:323 blocked for more than 122 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor424 state:D
 stack:0     pid:323   tgid:323   ppid:318    flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6063 [inline]
 __schedule+0x1496/0x20b0 kernel/sched/core.c:7883
 __schedule_loop kernel/sched/core.c:7960 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7975
 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common+0x368/0x650 kernel/sched/completion.c:127
 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
 __flush_work+0x6a8/0xaa0 kernel/workqueue.c:4290
 __cancel_work_sync kernel/workqueue.c:4411 [inline]
 cancel_work_sync+0xac/0xe0 kernel/workqueue.c:4448
 uhid_dev_destroy drivers/hid/uhid.c:584 [inline]
 uhid_char_release+0xa7/0x600 drivers/hid/uhid.c:662
 __fput+0x20b/0xa30 fs/file_table.c:447
 __fput_sync+0x4a/0x70 fs/file_table.c:532
 __do_sys_close fs/open.c:1586 [inline]
 __se_sys_close+0x172/0x1f0 fs/open.c:1571
 __x64_sys_close+0x3c/0x60 fs/open.c:1571
 x64_sys_call+0x2560/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f2ec7e8b267
RSP: 002b:00007ffe73783970 EFLAGS: 00000202
 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 000055555e9f5480 RCX: 00007f2ec7e8b267
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe737839dc
R13: 00007f2ec7ef8468 R14: 0000000000000000 R15: 431bde82d7b634db
 </TASK>
INFO: task syz-executor424:327 blocked for more than 124 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor424 state:D
 stack:0     pid:327   tgid:327   ppid:320    flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6063 [inline]
 __schedule+0x1496/0x20b0 kernel/sched/core.c:7883
 __schedule_loop kernel/sched/core.c:7960 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7975
 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common+0x368/0x650 kernel/sched/completion.c:127
 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
 __flush_work+0x6a8/0xaa0 kernel/workqueue.c:4290
 __cancel_work_sync kernel/workqueue.c:4411 [inline]
 cancel_work_sync+0xac/0xe0 kernel/workqueue.c:4448
 uhid_dev_destroy drivers/hid/uhid.c:584 [inline]
 uhid_char_release+0xa7/0x600 drivers/hid/uhid.c:662
 __fput+0x20b/0xa30 fs/file_table.c:447
 __fput_sync+0x4a/0x70 fs/file_table.c:532
 __do_sys_close fs/open.c:1586 [inline]
 __se_sys_close+0x172/0x1f0 fs/open.c:1571
 __x64_sys_close+0x3c/0x60 fs/open.c:1571
 x64_sys_call+0x2560/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f2ec7e8b267
RSP: 002b:00007ffe73783970 EFLAGS: 00000202
 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 000055555e9f5480 RCX: 00007f2ec7e8b267
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe737839dc
R13: 00007f2ec7ef8468 R14: 0000000000000000 R15: 431bde82d7b634db
 </TASK>
INFO: task syz-executor424:328 blocked for more than 125 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor424 state:D
 stack:0     pid:328   tgid:328   ppid:322    flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6063 [inline]
 __schedule+0x1496/0x20b0 kernel/sched/core.c:7883
 __schedule_loop kernel/sched/core.c:7960 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7975
 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common+0x368/0x650 kernel/sched/completion.c:127
 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
 __flush_work+0x6a8/0xaa0 kernel/workqueue.c:4290
 __cancel_work_sync kernel/workqueue.c:4411 [inline]
 cancel_work_sync+0xac/0xe0 kernel/workqueue.c:4448
 uhid_dev_destroy drivers/hid/uhid.c:584 [inline]
 uhid_char_release+0xa7/0x600 drivers/hid/uhid.c:662
 __fput+0x20b/0xa30 fs/file_table.c:447
 __fput_sync+0x4a/0x70 fs/file_table.c:532
 __do_sys_close fs/open.c:1586 [inline]
 __se_sys_close+0x172/0x1f0 fs/open.c:1571
 __x64_sys_close+0x3c/0x60 fs/open.c:1571
 x64_sys_call+0x2560/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:4
 do_syscall_x64 arch/x86/entry/common.c:47 [inline]
 do_syscall_64+0x57/0xf0 arch/x86/entry/common.c:78
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f2ec7e8b267
RSP: 002b:00007ffe73783970 EFLAGS: 00000202
 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 000055555e9f5480 RCX: 00007f2ec7e8b267
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffe737839d8
R13: 00007ffe73783a10 R14: 0000000000000001 R15: 431bde82d7b634db
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 93cd2a7db6251899ee82c41fb24ebb4b8e8a6534
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2ba/0x2d0 lib/nmi_backtrace.c:114
 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:63
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
 cpumask_backtrace+0x1f/0x30 lib/nmi_backtrace.c:127
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline]
 watchdog+0xe45/0xf90 kernel/hung_task.c:423
 kthread+0x2c4/0x360 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 329 Comm: kworker/1:2 Not tainted syzkaller #0 93cd2a7db6251899ee82c41fb24ebb4b8e8a6534
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events uhid_device_add_worker
RIP: 0010:__sanitizer_cov_trace_switch+0xdb/0xf0 kernel/kcov.c:-1
Code: 48 c1 e3 05 4c 8d 63 28 4d 39 fc 77 9d 49 ff c6 4d 89 33 49 89 4c 1b 08 4d 89 54 1b 10 49 89 7c 1b 18 49 89 54 1b 20 eb 81 5b <41> 5c 41 5e 41 5f 5d e9 c9 41 20 04 cc 0f 1f 84 00 00 00 00 00 b8
RSP: 0018:ffffc90001366a00 EFLAGS: 00000246
RAX: 000000000000000a RBX: ffff0a1000000600 RCX: 0000000000000001
RDX: ffffffff85a1d586 RSI: ffffffff87e3cea0 RDI: 0000000000000075
RBP: ffffc90001366a18 R08: ffff88812c624c00 R09: 000000000000000a
R10: 0000000000000078 R11: 0000000000000000 R12: 0000000000000075
R13: ffff001000000600 R14: ffffffff85e92dea R15: 1ffffffff0bd25bd
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9582a836e8 CR3: 0000000120264000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 format_decode+0x816/0x1610 lib/vsprintf.c:2613
 vsnprintf+0xe6/0x1ad0 lib/vsprintf.c:2755
 sprintf+0xe8/0x140 lib/vsprintf.c:3007
 print_time kernel/printk/printk.c:1387 [inline]
 info_print_prefix+0x183/0x4a0 kernel/printk/printk.c:1416
 record_print_text+0x182/0x4b0 kernel/printk/printk.c:1465
 printk_get_next_message+0x2ab/0x9e0 kernel/printk/printk.c:3037
 console_emit_next_record kernel/printk/printk.c:3108 [inline]
 console_flush_all+0x3d0/0xc10 kernel/printk/printk.c:3242
 __console_flush_and_unlock kernel/printk/printk.c:3301 [inline]
 console_unlock+0xf8/0x2c0 kernel/printk/printk.c:3341
 vprintk_emit+0x282/0x650 kernel/printk/printk.c:2462
 dev_vprintk_emit+0x33c/0x400 drivers/base/core.c:4962
 dev_printk_emit+0xef/0x150 drivers/base/core.c:4973
 __dev_printk+0x17f/0x1b0 drivers/base/core.c:4985
 _dev_warn+0x11f/0x180 drivers/base/core.c:5029
 hid_parser_main+0x84d/0xde0 drivers/hid/hid-core.c:667
 hid_open_report+0x87f/0x1120 drivers/hid/hid-core.c:1313
 hid_parse include/linux/hid.h:1139 [inline]
 hid_generic_probe+0x42/0x90 drivers/hid/hid-generic.c:66
 __hid_device_probe drivers/hid/hid-core.c:2760 [inline]
 hid_device_probe+0x2ce/0x5f0 drivers/hid/hid-core.c:2797
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x2e4/0x8b0 drivers/base/dd.c:657
 __driver_probe_device+0x193/0x280 drivers/base/dd.c:799
 driver_probe_device+0x54/0x3f0 drivers/base/dd.c:829
 __device_attach_driver+0x2f1/0x4b0 drivers/base/dd.c:957
 bus_for_each_drv+0x267/0x300 drivers/base/bus.c:459
 __device_attach+0x2c4/0x3c0 drivers/base/dd.c:1029
 device_initial_probe+0x1e/0x30 drivers/base/dd.c:1078
 bus_probe_device+0x18b/0x270 drivers/base/bus.c:534
 device_add+0x7fd/0xbf0 drivers/base/core.c:3692
 hid_add_device+0x3c4/0x5a0 drivers/hid/hid-core.c:2943
 uhid_device_add_worker+0x49/0xf0 drivers/hid/uhid.c:73
 process_one_work kernel/workqueue.c:3273 [inline]
 process_scheduled_works+0x7f4/0x1060 kernel/workqueue.c:3354
 worker_thread+0xc99/0x13f0 kernel/workqueue.c:3435
 kthread+0x2c4/0x360 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (37):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/29 07:52 android16-6.12 da245f6c05a1 7bf4ea23 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/08/22 09:51 android16-6.12 e8c85685a629 1e72964b .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/08/12 09:44 android16-6.12 0db85ff78f60 f8d35649 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/07/30 04:29 android16-6.12 f1c9c21d1c2f 6ef5c1e2 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/07/06 19:37 android16-6.12 87f47a1fd4cf 88b240e4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/06/01 20:20 android16-6.12 266acb5558b2 8d8eeb3a .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/05/03 20:31 android16-6.12 8ed163f1fc8c a0d91488 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2025/09/14 20:26 android16-6.12 0668e45a4339 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2025/08/31 17:16 android16-6.12 6879524e1c5a 807a3b61 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2025/07/24 18:19 android16-6.12 379b99745e88 65d60d73 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2025/06/19 10:49 android16-6.12 30b14cdad458 ed3e87f7 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/10/05 08:00 android16-6.12 3a7d1771d492 57bbd979 .config strace log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/07/06 21:51 android16-6.12 87f47a1fd4cf 88b240e4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/07/06 16:42 android16-6.12 87f47a1fd4cf 88b240e4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/02/08 13:48 android16-6.12 6aeca23b5dee 4c131dc4 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2025/06/19 13:40 android16-6.12 30b14cdad458 ed3e87f7 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/09/20 23:23 android16-6.12 dde7e9bf027f 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/09/20 09:38 android16-6.12 dde7e9bf027f 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/09/16 19:00 android16-6.12 1107981d2d5c 12a0a44a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/08/26 09:52 android16-6.12 b6d34a1fb26b 6a91adb4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/08/17 02:11 android16-6.12 26014f6c6077 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/08/04 12:23 android16-6.12 4f986595e48e 9451e17e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/06/28 01:01 android16-6.12 220923cf9f76 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/04/28 01:27 android16-6.12 18d3876842e1 ce741359 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/04/19 02:45 android16-6.12 6532ca3bb1f7 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/04/17 12:49 android16-6.12 100d1d1c17f8 de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/03/27 03:22 android16-6.12 d73a8ddf419e 766b6434 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/03/06 01:57 android16-6.12 6a6bc2e596fe 31e9c887 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/02/28 01:10 android16-6.12 9791d9d4829d 2cf092b8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2026/02/21 05:57 android16-6.12 7712ca595283 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2025/11/04 07:03 android16-6.12 0d6730ee6542 686bf657 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2025/10/31 11:06 android16-6.12 0d6730ee6542 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2025/09/02 21:40 android16-6.12 4ae522d0f966 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2025/07/26 23:18 android16-6.12 e9bbc29c066a fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2025/07/17 07:57 android16-6.12 3bff0858a069 44f8051e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2025/07/15 08:50 android16-6.12 2bd1f3631412 03fcfc4b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
2025/07/08 18:13 android16-6.12 15d2fe054444 4d9fdfa4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in uhid_char_release
* Struck through repros no longer work on HEAD.