syzbot


INFO: rcu detected stall in hub_event (2)

Status: upstream: reported C repro on 2025/08/21 02:14
Subsystems: usb kernfs
[Documentation on labels]
Reported-by: syzbot+039eab266c6321a174bd@syzkaller.appspotmail.com
First crash: 330d, last: 4d16h
Cause bisection: failed (error log, bisect log)
  
Discussions (3)
Title Replies (including bot) Last reply
[syzbot] Monthly kernfs report (Mar 2026) 0 (1) 2026/03/31 08:06
[syzbot] Monthly kernfs report (Oct 2025) 0 (1) 2025/10/24 18:48
[syzbot] [mm?] INFO: rcu detected stall in hub_event (2) 0 (3) 2025/09/17 17:52
Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in hub_event 1 2 511d 597d 0/3 auto-obsoleted due to no activity on 2025/02/15 14:48
upstream INFO: rcu detected stall in hub_event usb 1 C done 1233 331d 2324d 28/29 fixed on 2025/05/06 15:33
linux-6.1 INFO: rcu detected stall in hub_event origin:lts-only 1 C inconclusive 6 316d 964d 0/3 upstream: reported C repro on 2023/08/12 16:34
android-5-15 BUG: soft lockup in hub_event 1 12 645d 715d 0/2 auto-obsoleted due to no activity on 2024/09/23 11:46
android-54 BUG: soft lockup in hub_event 1 C 1 935d 935d 0/2 auto-obsoleted due to no activity on 2024/02/11 21:05
android-6-1 BUG: soft lockup in hub_event 1 1 1023d 1023d 0/2 auto-obsoleted due to no activity on 2023/09/12 05:32
Last patch testing requests (3)
Created Duration User Patch Repo Result
2025/10/14 21:09 22m retest repro upstream OK log
2025/10/14 21:09 24m retest repro upstream OK log
2025/10/14 21:09 22m retest repro upstream report log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1):
 P3032/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=42045, q=380374 ncpus=2)
task:kworker/1:2     state:R  running task    
 stack:23640 pid:3032  tgid:3032  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0xeb1/0x4220 kernel/sched/core.c:6911
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7238
 irqentry_exit+0x15a/0x620 kernel/entry/common.c:239
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x5e/0x380 kernel/locking/lockdep.c:5872
Code: 05 3b 44 66 0b 83 f8 07 0f 87 f0 00 00 00 48 0f a3 05 c6 20 61 09 0f 82 c2 02 00 00 8b 35 6e 30 61 09 85 f6 0f 85 dd 00 00 00 <48> 8b 44 24 30 65 48 2b 05 dd 43 66 0b 0f 85 02 03 00 00 48 83 c4
RSP: 0018:ffffc9000191e998 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000006
RDX: 0000000000000000 RSI: ffffffff890010b3 RDI: ffffffff87afc6a0
RBP: ffffffff896de6e0 R08: 0000000055b0517e R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
 __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __do_kmalloc_node mm/slub.c:5260 [inline]
 __kmalloc_noprof+0x302/0x810 mm/slub.c:5272
 kmalloc_noprof include/linux/slab.h:954 [inline]
 kobj_map+0x80/0x4b0 drivers/base/map.c:44
 cdev_add+0xa7/0x1a0 fs/char_dev.c:488
 cdev_device_add+0x10f/0x270 fs/char_dev.c:548
 evdev_connect+0x3a8/0x4b0 drivers/input/evdev.c:1383
 input_attach_handler.isra.0+0x177/0x1e0 drivers/input/input.c:994
 input_register_device.cold+0x139/0x375 drivers/input/input.c:2378
 usb_probe+0x1226/0x17c0 drivers/input/misc/yealink.c:928
 usb_probe_interface+0x303/0x8f0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:583 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:661
 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:803
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:833
 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:961
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1033
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1088
 bus_probe_device+0x64/0x160 drivers/base/bus.c:574
 device_add+0x11d9/0x1950 drivers/base/core.c:3689
 usb_set_configuration+0xd97/0x1c60 drivers/usb/core/message.c:2268
 usb_generic_driver_probe+0xa1/0xe0 drivers/usb/core/generic.c:250
 usb_probe_device+0xef/0x400 drivers/usb/core/driver.c:291
 call_driver_probe drivers/base/dd.c:583 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:661
 __driver_probe_device+0x1de/0x400 drivers/base/dd.c:803
 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:833
 __device_attach_driver+0x1df/0x340 drivers/base/dd.c:961
 bus_for_each_drv+0x159/0x1e0 drivers/base/bus.c:500
 __device_attach+0x1e4/0x4d0 drivers/base/dd.c:1033
 device_initial_probe+0xaf/0xd0 drivers/base/dd.c:1088
 bus_probe_device+0x64/0x160 drivers/base/bus.c:574
 device_add+0x11d9/0x1950 drivers/base/core.c:3689
 usb_new_device.cold+0x685/0x115c drivers/usb/core/hub.c:2695
 hub_port_connect drivers/usb/core/hub.c:5567 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5707 [inline]
 port_event drivers/usb/core/hub.c:5871 [inline]
 hub_event+0x314d/0x4af0 drivers/usb/core/hub.c:5953
 process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
 process_scheduled_works kernel/workqueue.c:3359 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x6c3/0xcb0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (460):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/03/29 03:34 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 84db3719d273 b5ceaad2 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/28 18:37 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 84db3719d273 b5ceaad2 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/02/12 14:33 upstream c22e26bd0906 76a109e2 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in hub_event
2026/01/13 17:34 upstream b71e635feefc d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in hub_event
2025/09/06 03:05 upstream c8ed9b5c02a5 d291dd2d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in hub_event
2026/03/22 05:51 upstream 113ae7b4decc 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in hub_event
2026/03/14 15:26 upstream 1c9982b49613 ee8d34d6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in hub_event
2026/03/13 08:13 upstream 0257f64bdac7 2f7f359d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in hub_event
2025/09/17 17:51 upstream 5aca7966d2a7 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in hub_event
2025/09/07 22:48 upstream 6ab41fca2e80 d291dd2d .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in hub_event
2025/08/17 02:03 upstream 90d970cade8e 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in hub_event
2025/08/11 23:28 upstream 8f5ae30d69d7 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in hub_event
2026/03/28 18:28 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 84db3719d273 b5ceaad2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/26 01:44 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 84db3719d273 c6143aac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/22 13:48 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 84db3719d273 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/21 11:17 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 84db3719d273 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/21 09:19 linux-next 785f0eb2f85d 5b92003d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: rcu detected stall in hub_event
2026/03/19 19:38 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 84db3719d273 bd6dcb30 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/19 10:38 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 84db3719d273 0199f9a1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/19 01:02 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing d3d959404e6c 0199f9a1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/17 12:45 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing de6c925db978 c01bca74 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/12 14:09 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 322a81d35ecd 4efadf07 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/11 06:48 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing bb375c251ab4 86914af9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/10 12:29 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing bb375c251ab4 6972f302 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/09 04:58 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing bb375c251ab4 5cb44a80 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/04 23:49 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing bb375c251ab4 a9fe5c9e .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/04 05:50 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing bb375c251ab4 4180d919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/04 04:39 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing bb375c251ab4 4180d919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/03 22:43 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing bb375c251ab4 4180d919 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/03/03 04:12 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing bb375c251ab4 28b83e23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/02/28 11:50 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing bb375c251ab4 43249bac .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/02/27 09:47 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing bb375c251ab4 a2f13f71 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/02/25 05:43 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 6de23f81a5e0 787dfb7c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/02/23 22:18 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 6de23f81a5e0 41d2fa6a .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/02/15 20:38 linux-next 635c467cc14e 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: rcu detected stall in hub_event
2026/02/13 14:27 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 6a673c50 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in hub_event
2026/01/07 01:29 linux-next 6cd6c1203113 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in hub_event
2026/02/17 21:31 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 06ec4f7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/17 19:10 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 06ec4f7b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/17 06:38 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 e439b951 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/16 18:09 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 5d52cba5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/16 04:19 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/16 02:31 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/16 01:14 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/15 19:23 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/15 13:31 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/15 03:39 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/14 10:51 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/14 01:29 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/13 18:47 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/12 19:15 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 504cb1bf .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/12 09:14 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/12 07:47 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/12 06:28 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/12 01:14 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/11 19:48 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 75707236 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/11 09:43 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/11 06:00 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/11 02:33 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 441e25b7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/10 22:42 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
2026/02/10 21:04 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing da87d45b1951 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb BUG: soft lockup in hub_event
* Struck through repros no longer work on HEAD.