INFO: rcu detected stall in sys_close (7)

Status: upstream: reported C repro on 2024/04/19 01:14
Subsystems: fs
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+393022c13d02e1f680e3@syzkaller.appspotmail.com
First crash: 880d, last: 13d
Cause bisection: failed (error log, bisect log)
  
▶ ▼ ✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
2136dec0 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ✅ VMHostTrigger: ❌ ❓ INFO: rcu detected stall in sys_close (7) 2026/05/19 00:42 2026/05/19 00:42 2026/05/19 01:24 9f74d399
▶ ▼ Discussions (3)
Title Replies (including bot) Last reply
[syzbot] Monthly fs report (Sep 2026) 0 (1) 2026/09/11 04:33
[syzbot] Monthly bpf report (Nov 2025) 0 (1) 2025/11/05 08:25
[syzbot] [fs?] [usb?] [input?] INFO: rcu detected stall in sys_close (7) 0 (1) 2024/04/19 01:14
▶ ▼ Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_close (3) kernel 1 1 1478d 1478d 0/29 auto-obsoleted due to no activity on 2022/10/25 14:50
linux-5.15 INFO: rcu detected stall in sys_close (2) 1 1 299d 299d 0/3 auto-obsoleted due to no activity on 2026/02/25 04:01
upstream INFO: rcu detected stall in sys_close (4) fs 1 1 1401d 1401d 0/29 auto-obsoleted due to no activity on 2023/02/13 19:04
linux-5.15 INFO: rcu detected stall in sys_close 1 1 867d 867d 0/3 auto-obsoleted due to no activity on 2024/08/05 21:33
linux-6.6 INFO: rcu detected stall in close origin:lts-only 1 syz, C error 2 256d 276d 0/2 upstream: reported C repro on 2025/12/10 03:57
linux-5.15 INFO: rcu detected stall in sys_close (3) 1 1 36d 36d 0/3 upstream: reported on 2026/08/07 05:33
linux-6.1 INFO: rcu detected stall in sys_close (2) 1 2 21d 84d 0/3 upstream: reported on 2026/06/20 04:40
linux-6.1 INFO: rcu detected stall in sys_close origin:lts-only 1 syz, C done 1 281d 313d 3/3 fixed on 2026/01/11 15:32
upstream INFO: rcu detected stall in sys_close fs 1 1 1716d 1716d 0/29 closed as invalid on 2022/02/08 10:10
upstream INFO: rcu detected stall in sys_close (6) fs 1 3 975d 1056d 0/29 auto-obsoleted due to no activity on 2024/04/10 05:01
upstream INFO: rcu detected stall in sys_close (2) fs 1 3 1573d 1623d 0/29 auto-closed as invalid on 2022/08/21 03:13
upstream INFO: rcu detected stall in sys_close (5) net 1 syz, C done 1 1110d 1110d 23/29 fixed on 2023/10/12 12:48
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/06/09 00:44 26m retest repro linux-next log
2026/04/26 22:46 39m retest repro linux-next no crash log
2026/04/26 22:42 31m retest repro linux-next no crash log
2026/03/30 21:27 38m retest repro linux-next report log
2026/02/15 20:50 31m retest repro linux-next report log
2026/01/19 20:09 39m retest repro linux-next no crash log
2026/01/19 20:09 18m retest repro linux-next error
2025/12/07 18:23 57m retest repro linux-next report log
2025/09/09 21:38 27m retest repro linux-next report log
2025/07/01 17:43 56m retest repro linux-next report log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=f8dc/1/0x4000000000000000 softirq=17634/17634 fqs=1
rcu: 	(detected by 0, t=10502 jiffies, g=14721, q=823 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5705 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:__raw_callee_save___pv_queued_spin_unlock+0x10/0x18
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 52 b8 01 00 00 00 31 d2 f0 0f b0 17 <75> 06 5a e9 18 3f 00 00 56 0f b6 f0 e8 9f ff ff ff 5e 5a e9 08 3f
RSP: 0018:ffffc90000a18d60 EFLAGS: 00000046
RAX: 0000000000000001 RBX: ffff8880b8728280 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880b8728280
RBP: 1ffff110170e5051 R08: ffff8880b8728283 R09: 1ffff110170e5050
R10: dffffc0000000000 R11: ffffed10170e5051 R12: dffffc0000000000
R13: 1ffff110170e5052 R14: ffff8880b8728290 R15: ffff8880b8728288
FS:  00007f386d27b880(0000) GS:ffff888124de0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0a86d83ff8 CR3: 000000002a39e000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 pv_queued_spin_unlock arch/x86/include/asm/paravirt-spinlock.h:44 [inline]
 queued_spin_unlock arch/x86/include/asm/paravirt-spinlock.h:77 [inline]
 do_raw_spin_unlock+0xf5/0x200 kernel/locking/spinlock_debug.c:142
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:209 [inline]
 _raw_spin_unlock_irqrestore+0x23/0x80 kernel/locking/spinlock.c:221
 __run_hrtimer kernel/time/hrtimer.c:2063 [inline]
 __hrtimer_run_queues+0x2bf/0xa10 kernel/time/hrtimer.c:2124
 hrtimer_interrupt+0x4cd/0xaa0 kernel/time/hrtimer.c:2243
 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:lock_acquire+0x232/0x350 kernel/locking/lockdep.c:5913
Code: ff ff ff e8 40 dc 3f 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 92 e7 f0 11 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 07 23 da
RSP: 0018:ffffc900036cfe60 EFLAGS: 00000296
RAX: e30bd21c5a073700 RBX: 0000000000000001 RCX: 8000000000000001
RDX: 00000000003b547d RSI: ffffffff8e6fac39 RDI: ffffffff8c6d8b80
RBP: ffff88807dfb0000 R08: 9800000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffff888034f28858 R12: ffff888034f28858
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000246
 __raw_spin_lock include/linux/spinlock_api_smp.h:190 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:173
 spin_lock include/linux/spinlock.h:347 [inline]
 file_close_fd+0x50/0x80 fs/file.c:883
 __do_sys_close fs/open.c:1550 [inline]
 __se_sys_close fs/open.c:1545 [inline]
 __x64_sys_close+0x3c/0x110 fs/open.c:1545
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f386caa7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fffbd5a16d0 EFLAGS: 00000202 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f386d27b880 RCX: 00007f386caa7407
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000009
RBP: 0000555e04ab0bb0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000555e04a3eb40
R13: 00007fffbd5a2340 R14: 00007fffbd5a1f40 R15: 00007fffbd5a1b40
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g14721 f0x0 RCU_GP_WAIT_FQS(5) ->state=I
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=3924
rcu: rcu_preempt kthread starved for 10500 jiffies! g14721 f0x0 RCU_GP_WAIT_FQS(5) ->state=I ->cpu=1
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:27496 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5520 [inline]
 __schedule+0x17d4/0x5820 kernel/sched/core.c:7270
 __schedule_loop kernel/sched/core.c:7347 [inline]
 schedule+0x164/0x2b0 kernel/sched/core.c:7362
 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330
 kthread+0x38b/0x480 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>

Crashes (25):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/30 04:07 net-next 1b78070aaef6 2f52988a .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in sys_close
2026/08/30 14:12 upstream 08dbfad3f504 2f52988a .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: rcu detected stall in sys_close
2025/12/24 18:56 linux-next cc3aa43b44bd d6526ea3 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_close
2026/08/20 00:22 upstream 98f21c54f995 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_close
2026/08/12 17:45 upstream 3d6d817622b0 7ae4acc7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_close
2026/06/25 07:36 upstream ab9de95c9cf9 cfa969bf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in sys_close
2025/11/16 09:55 upstream f824272b6e3f f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_close
2025/05/14 16:59 upstream 9f35e33144ae a4fa04ef .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_close
2025/04/08 10:04 upstream 0af2f6be1b42 a775275d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_close
2024/12/31 05:39 upstream ccb98ccef0e5 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_close
2024/12/19 12:26 upstream eabcdba3ad40 1432fc84 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_close
2024/09/18 12:32 upstream bdf56c7580d2 c673ca06 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_close
2026/06/19 12:40 net 5c121ee63568 d7ffd47b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_close
2024/10/10 16:41 net a354733c738d 8fbfc0c8 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_close
2024/12/31 01:00 net-next 9268abe611b0 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in sys_close
2026/05/12 03:25 linux-next e98d21c170b0 d168f260 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_close
2026/01/05 19:40 linux-next f8f97927abf7 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_close
2025/12/25 07:54 linux-next cc3aa43b44bd d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_close
2025/12/23 15:33 linux-next cc3aa43b44bd d6526ea3 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_close
2025/11/23 16:51 linux-next d724c6f85e80 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_close
2025/10/29 17:59 linux-next f9ba12abc528 fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_close
2025/10/13 10:27 linux-next 2b763d465239 ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_close
2024/10/21 21:01 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing c6d9e43954bf f1e4447c .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in sys_close
2024/10/16 18:45 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing 7b5a58952fc3 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in sys_close
2024/04/15 01:02 linux-next 9ed46da14b9b c8349e48 .config console log report syz C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_close
* Struck through repros no longer work on HEAD.