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INFO: rcu detected stall in v4l2_ioctl (3)

Status: auto-obsoleted due to no activity on 2025/10/25 18:43
Subsystems: kasan mm
[Documentation on labels]
First crash: 166d, last: 134d
▶ ▼ Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in v4l2_ioctl (2) mm 1 3 391d 437d 0/29 auto-obsoleted due to no activity on 2025/02/10 18:30
upstream INFO: rcu detected stall in v4l2_ioctl fs mm 1 1 1323d 1323d 0/29 auto-closed as invalid on 2022/06/24 20:18

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=d114/1/0x4000000000000000 softirq=67146/67146 fqs=1
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6971/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=65661, q=151 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 14884 Comm: syz.1.3145 Not tainted 6.16.0-rc7-syzkaller-00142-gb711733e89a3 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__netif_schedule+0x269/0x2c0 net/core/dev.c:3381
Code: 02 19 02 4d 85 f6 74 ea e8 34 80 6b f8 fb 48 c7 44 24 20 0e 36 e0 45 48 b8 00 00 00 00 00 fc ff df 49 c7 44 05 00 00 00 00 00 <66> 41 c7 44 05 09 00 00 41 c6 44 05 0b 00 65 48 8b 05 41 29 4b 09
RSP: 0018:ffffc90000a08b80 EFLAGS: 00000006
RAX: dffffc0000000000 RBX: ffff88806d2cc000 RCX: ffff88802f19da00
RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc90000a08c60 R08: ffff88806d2cc15f R09: 1ffff1100da5982b
R10: dffffc0000000000 R11: ffffed100da5982c R12: ffff88806d2cc360
R13: 1ffff92000141174 R14: 185d2d19f8000000 R15: ffff888056505000
FS:  00007fc58a52d6c0(0000) GS:ffff888125d23000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fc5875f5f98 CR3: 000000006127a000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 advance_sched+0xa9a/0xc90 net/sched/sch_taprio.c:986
 __run_hrtimer kernel/time/hrtimer.c:1761 [inline]
 __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 5b 94 01 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000b5c7120 EFLAGS: 00000206
RAX: 2728b40810e9a700 RBX: 0000000000000000 RCX: 2728b40810e9a700
RDX: 0000000000000000 RSI: ffffffff8db845d7 RDI: ffffffff8be28dc0
RBP: ffffffff822d50ca R08: 0000000000000000 R09: ffffffff822d50ca
R10: dffffc0000000000 R11: ffffed100a86df6e R12: 0000000000000002
R13: ffffffff8e13f0e0 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 __page_table_check_zero+0xd7/0x530 mm/page_table_check.c:138
 page_table_check_alloc include/linux/page_table_check.h:35 [inline]
 post_alloc_hook+0x253/0x2a0 mm/page_alloc.c:1705
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 alloc_frozen_pages_noprof mm/mempolicy.c:2490 [inline]
 alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2510
 vm_area_alloc_pages mm/vmalloc.c:3642 [inline]
 __vmalloc_area_node mm/vmalloc.c:3720 [inline]
 __vmalloc_node_range_noprof+0x97d/0x12f0 mm/vmalloc.c:3893
 vmalloc_user_noprof+0xad/0xf0 mm/vmalloc.c:4046
 vb2_vmalloc_alloc+0xef/0x340 drivers/media/common/videobuf2/videobuf2-vmalloc.c:47
 __vb2_buf_mem_alloc drivers/media/common/videobuf2/videobuf2-core.c:242 [inline]
 __vb2_queue_alloc+0x9c2/0x15a0 drivers/media/common/videobuf2/videobuf2-core.c:523
 vb2_core_reqbufs+0xc31/0x1420 drivers/media/common/videobuf2/videobuf2-core.c:964
 v4l2_m2m_reqbufs drivers/media/v4l2-core/v4l2-mem2mem.c:582 [inline]
 v4l2_m2m_ioctl_reqbufs+0x10d/0x200 drivers/media/v4l2-core/v4l2-mem2mem.c:1376
 __video_do_ioctl+0xc9b/0xdb0 drivers/media/v4l2-core/v4l2-ioctl.c:3132
 video_usercopy+0x871/0x14f0 drivers/media/v4l2-core/v4l2-ioctl.c:3473
 v4l2_ioctl+0x18d/0x1e0 drivers/media/v4l2-core/v4l2-dev.c:366
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc58978e9a9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc58a52d038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc5899b5fa0 RCX: 00007fc58978e9a9
RDX: 00002000000000c0 RSI: 00000000c0145608 RDI: 0000000000000003
RBP: 00007fc589810d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc5899b5fa0 R15: 00007ffe92849598
 </TASK>
task:syz-executor    state:R  running task     stack:17800 pid:6971  tgid:6971  ppid:6933   task_flags:0x400140 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__rcu_read_unlock+0x0/0xe0 kernel/rcu/tree_plugin.h:431
Code: 89 d9 80 e1 07 80 c1 03 38 c1 7c dc 48 89 df e8 26 57 7a 00 eb d2 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 41 57 41 56 41 55 41 54 53 49 bf 00 00 00 00 00 fc ff
RSP: 0018:ffffc9001ecaf150 EFLAGS: 00000282
RAX: b7aed739bc515b00 RBX: ffffffff9032df01 RCX: b7aed739bc515b00
RDX: 0000000000000000 RSI: ffffffff8db845d7 RDI: ffffffff8be28dc0
RBP: dffffc0000000000 R08: ffffc9001ecafec0 R09: ffffc9001ecaf278
R10: dffffc0000000000 R11: fffff52003d95e51 R12: ffffc9001ecafed0
R13: ffffc9001eca8000 R14: ffffc9001ecaf228 R15: ffffffff8172aae5
 rcu_read_unlock include/linux/rcupdate.h:873 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0x19ae/0x2390 arch/x86/kernel/unwind_orc.c:680
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 save_stack+0xf5/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 free_unref_folios+0xc66/0x14d0 mm/page_alloc.c:2763
 folios_put_refs+0x559/0x640 mm/swap.c:992
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x49e/0x14b0 mm/shmem.c:1125
 shmem_truncate_range mm/shmem.c:1237 [inline]
 shmem_evict_inode+0x272/0xa70 mm/shmem.c:1365
 evict+0x504/0x9c0 fs/inode.c:810
 __dentry_kill+0x209/0x660 fs/dcache.c:669
 dput+0x19f/0x2b0 fs/dcache.c:911
 __fput+0x68e/0xa70 fs/file_table.c:473
 task_work_run+0x1d4/0x260 kernel/task_work.c:227
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc455d8fcd7
RSP: 002b:00007ffca7d20d58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fc455e10b55 RCX: 00007fc455d8fcd7
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffca7d20e10
RBP: 00007ffca7d20e10 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffca7d21ea0
R13: 00007fc455e10b55 R14: 000000000006ef7c R15: 00007ffca7d21ee0
 </TASK>
rcu: rcu_preempt kthread starved for 10495 jiffies! g65661 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:27320 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5397 [inline]
 __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786
 __schedule_loop kernel/sched/core.c:6864 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6879
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 796 Comm: kworker/u8:5 Not tainted 6.16.0-rc7-syzkaller-00142-gb711733e89a3 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xf6e/0x12d0 kernel/smp.c:885
Code: 89 ee 83 e6 01 31 ff e8 90 6e 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 3b 6a 0b 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 07 01 00 00 00 74 1e e8 20 6a 0b 00 eb e5 44 89
RSP: 0018:ffffc900031d76a0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b863b1c0 RCX: ffff888024565a00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900031d7800 R08: ffffffff8fa1ddf7 R09: 1ffffffff1f43bbe
R10: dffffc0000000000 R11: fffffbfff1f43bbf R12: 1ffff110170e7f5d
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b873fae8
FS:  0000000000000000(0000) GS:ffff888125c23000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555844d35c8 CR3: 000000000df38000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
 on_each_cpu include/linux/smp.h:71 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2691 [inline]
 smp_text_poke_batch_finish+0x5e0/0x1100 arch/x86/kernel/alternative.c:2901
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/27 18:34 upstream b711733e89a3 fb8f743d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in v4l2_ioctl
2025/06/25 07:50 upstream 7595b66ae9de 26d77996 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in v4l2_ioctl
* Struck through repros no longer work on HEAD.