INFO: rcu detected stall in drm_release (4)

Status: auto-obsoleted due to no activity on 2026/09/17 05:42
Subsystems: mm
Labels: prio:low
[Documentation on labels]
First crash: 112d, last: 96d
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ID Workflow Result Correct Bug Created Started Finished Revision
7ae250aa assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: rcu detected stall in drm_release (4) 2026/06/09 17:20 2026/06/09 17:20 2026/06/09 18:06 c36c07f6
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in drm_release (2) mm 1 1 442d 442d 0/29 auto-obsoleted due to no activity on 2025/10/06 04:27
upstream INFO: rcu detected stall in drm_release mm 1 1 538d 538d 0/29 auto-obsoleted due to no activity on 2025/07/02 13:18
upstream INFO: rcu detected stall in drm_release (3) mm 1 3 214d 226d 0/29 auto-obsoleted due to no activity on 2026/05/23 02:56

Sample crash report:
[drm:vkms_crtc_handle_vblank_timeout] *ERROR* vkms failure on handling vblank
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P16/2:b..l P20027
rcu: 	(detected by 0, t=10502 jiffies, g=76757, q=1763 ncpus=2)
task:syz.7.4964      state:R  running task     stack:25208 pid:20027 tgid:20027 ppid:19019  task_flags:0x400040 flags:0x00080000
Call Trace:
 <IRQ>
 sched_show_task+0x4aa/0x5f0 kernel/sched/core.c:8180
 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline]
 print_other_cpu_stall+0xf7b/0x1310 kernel/rcu/tree_stall.h:680
 check_cpu_stall kernel/rcu/tree_stall.h:855 [inline]
 rcu_pending kernel/rcu/tree.c:3708 [inline]
 rcu_sched_clock_irq+0x93d/0x1050 kernel/rcu/tree.c:2744
 update_process_times+0x234/0x2d0 kernel/time/timer.c:2475
 tick_sched_handle kernel/time/tick-sched.c:296 [inline]
 tick_nohz_handler+0x38f/0x6b0 kernel/time/tick-sched.c:317
 __run_hrtimer kernel/time/hrtimer.c:2032 [inline]
 __hrtimer_run_queues+0x3a0/0xaf0 kernel/time/hrtimer.c:2096
 hrtimer_interrupt+0x44a/0x900 kernel/time/hrtimer.c:2215
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198
Code: f7 e8 1d 81 7d f6 f7 c3 00 02 00 00 74 05 e8 20 67 a9 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 04 a2 6f f6 65 8b 05 dd 5f 49 07 85 c0 74 18 5b 41 5e e9 41 3c
RSP: 0018:ffffc90003ec75c0 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000246 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8ba7d600 RDI: 0000000000000001
RBP: 00000000ffffffff R08: ffffffff8f8974f7 R09: 1ffffffff1f12e9e
R10: dffffc0000000000 R11: fffffbfff1f12e9f R12: dffffc0000000000
R13: ffff8880b8828780 R14: ffff8880b8828440 R15: 1ffff110171050f0
 unlock_hrtimer_base kernel/time/hrtimer.c:1039 [inline]
 hrtimer_try_to_cancel+0x4a7/0x680 kernel/time/hrtimer.c:1634
 drm_crtc_vblank_start_timer+0xeb/0x240 drivers/gpu/drm/drm_vblank.c:2239
 __enable_vblank drivers/gpu/drm/drm_vblank.c:1176 [inline]
 drm_vblank_enable+0x1b3/0x460 drivers/gpu/drm/drm_vblank.c:1199
 drm_vblank_get+0x11f/0x280 drivers/gpu/drm/drm_vblank.c:1235
 vkms_crtc_atomic_flush+0x92/0x1e0 drivers/gpu/drm/vkms/vkms_crtc.c:180
 drm_atomic_helper_commit_planes+0xbb1/0xea0 drivers/gpu/drm/drm_atomic_helper.c:3058
 vkms_atomic_commit_tail+0x5e/0x220 drivers/gpu/drm/vkms/vkms_drv.c:74
 commit_tail+0x29b/0x3c0 drivers/gpu/drm/drm_atomic_helper.c:2072
 drm_atomic_helper_commit+0xa77/0xb10 drivers/gpu/drm/drm_atomic_helper.c:2312
 drm_atomic_commit+0x24e/0x2b0 drivers/gpu/drm/drm_atomic.c:1789
 drm_client_modeset_commit_atomic+0x660/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1104
 drm_client_modeset_commit_locked+0xce/0x4d0 drivers/gpu/drm/drm_client_modeset.c:1207
 drm_client_modeset_commit+0x4a/0x70 drivers/gpu/drm/drm_client_modeset.c:1233
 __drm_fb_helper_restore_fbdev_mode_unlocked+0x9c/0x1c0 drivers/gpu/drm/drm_fb_helper.c:138
 drm_fbdev_client_restore+0x1b/0x30 drivers/gpu/drm/clients/drm_fbdev_client.c:45
 drm_client_dev_restore+0x14f/0x290 drivers/gpu/drm/drm_client_event.c:118
 drm_lastclose drivers/gpu/drm/drm_file.c:408 [inline]
 drm_release+0x343/0x410 drivers/gpu/drm/drm_file.c:441
 __fput+0x42a/0xa80 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f145875ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffecf6f9e28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f14589d7da0 RCX: 00007f145875ce59
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f14589d7da0 R08: 00007f14589d6038 R09: 0000000000000000
R10: 00000000003feee4 R11: 0000000000000246 R12: 00000000000ad387
R13: 00007f14589d609c R14: 00000000000ad13f R15: 00007f14589d6090
 </TASK>
task:ktimers/0       state:R  running task     stack:23376 pid:16    tgid:16    ppid:2      task_flags:0x4208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5504 [inline]
 __schedule+0x16dc/0x5500 kernel/sched/core.c:7228
 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7409
 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12
 rt_mutex_wake_up_q kernel/locking/rtmutex.c:583 [inline]
 rt_mutex_slowunlock+0x6d1/0xa20 kernel/locking/rtmutex.c:1483
 spin_unlock include/linux/spinlock_rt.h:109 [inline]
 vkms_crtc_handle_vblank_timeout+0x83/0x290 drivers/gpu/drm/vkms/vkms_crtc.c:30
 drm_vblank_timer_function+0x19a/0x210 drivers/gpu/drm/drm_vblank.c:2199
 __run_hrtimer kernel/time/hrtimer.c:2032 [inline]
 __hrtimer_run_queues+0x3eb/0xaf0 kernel/time/hrtimer.c:2096
 hrtimer_run_softirq+0x18f/0x260 kernel/time/hrtimer.c:2113
 handle_softirqs+0x1d9/0x6c0 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 run_ktimerd+0x69/0x100 kernel/softirq.c:1151
 smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 9853 jiffies! g76757 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=47589
rcu: rcu_preempt kthread starved for 9854 jiffies! g76757 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27768 pid:18    tgid:18    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5504 [inline]
 __schedule+0x16dc/0x5500 kernel/sched/core.c:7228
 __schedule_loop kernel/sched/core.c:7307 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7322
 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 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: 20027 Comm: syz.7.4964 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198
Code: f7 e8 1d 81 7d f6 f7 c3 00 02 00 00 74 05 e8 20 67 a9 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 04 a2 6f f6 65 8b 05 dd 5f 49 07 85 c0 74 18 5b 41 5e e9 41 3c
RSP: 0018:ffffc90003ec75c0 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000246 RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8ba7d600 RDI: 0000000000000001
RBP: 00000000ffffffff R08: ffffffff8f8974f7 R09: 1ffffffff1f12e9e
R10: dffffc0000000000 R11: fffffbfff1f12e9f R12: dffffc0000000000
R13: ffff8880b8828780 R14: ffff8880b8828440 R15: 1ffff110171050f0
FS:  000055557e58e500(0000) GS:ffff88812614f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f13a8368060 CR3: 000000007c1de000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 unlock_hrtimer_base kernel/time/hrtimer.c:1039 [inline]
 hrtimer_try_to_cancel+0x4a7/0x680 kernel/time/hrtimer.c:1634
 drm_crtc_vblank_start_timer+0xeb/0x240 drivers/gpu/drm/drm_vblank.c:2239
 __enable_vblank drivers/gpu/drm/drm_vblank.c:1176 [inline]
 drm_vblank_enable+0x1b3/0x460 drivers/gpu/drm/drm_vblank.c:1199
 drm_vblank_get+0x11f/0x280 drivers/gpu/drm/drm_vblank.c:1235
 vkms_crtc_atomic_flush+0x92/0x1e0 drivers/gpu/drm/vkms/vkms_crtc.c:180
 drm_atomic_helper_commit_planes+0xbb1/0xea0 drivers/gpu/drm/drm_atomic_helper.c:3058
 vkms_atomic_commit_tail+0x5e/0x220 drivers/gpu/drm/vkms/vkms_drv.c:74
 commit_tail+0x29b/0x3c0 drivers/gpu/drm/drm_atomic_helper.c:2072
 drm_atomic_helper_commit+0xa77/0xb10 drivers/gpu/drm/drm_atomic_helper.c:2312
 drm_atomic_commit+0x24e/0x2b0 drivers/gpu/drm/drm_atomic.c:1789
 drm_client_modeset_commit_atomic+0x660/0x7e0 drivers/gpu/drm/drm_client_modeset.c:1104
 drm_client_modeset_commit_locked+0xce/0x4d0 drivers/gpu/drm/drm_client_modeset.c:1207
 drm_client_modeset_commit+0x4a/0x70 drivers/gpu/drm/drm_client_modeset.c:1233
 __drm_fb_helper_restore_fbdev_mode_unlocked+0x9c/0x1c0 drivers/gpu/drm/drm_fb_helper.c:138
 drm_fbdev_client_restore+0x1b/0x30 drivers/gpu/drm/clients/drm_fbdev_client.c:45
 drm_client_dev_restore+0x14f/0x290 drivers/gpu/drm/drm_client_event.c:118
 drm_lastclose drivers/gpu/drm/drm_file.c:408 [inline]
 drm_release+0x343/0x410 drivers/gpu/drm/drm_file.c:441
 __fput+0x42a/0xa80 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
 do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f145875ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffecf6f9e28 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f14589d7da0 RCX: 00007f145875ce59
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f14589d7da0 R08: 00007f14589d6038 R09: 0000000000000000
R10: 00000000003feee4 R11: 0000000000000246 R12: 00000000000ad387
R13: 00007f14589d609c R14: 00000000000ad13f R15: 00007f14589d6090
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/19 05:38 upstream 8c13415c8a43 d7ffd47b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in drm_release
2026/06/03 14:21 upstream ba3e43a9e601 234057e5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in drm_release
* Struck through repros no longer work on HEAD.