INFO: rcu detected stall in cleanup_mnt (2)

Status: upstream: reported C repro on 2024/08/10 23:43
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+09e7336b5c7f5b7fa856@syzkaller.appspotmail.com
First crash: 736d, last: 1d14h
Fix commit to backport (bisect log) :
tree: upstream
commit e634134180885574d1fe7aa162777ba41e7fcd5b
Author: Vladimir Oltean <vladimir.oltean@nxp.com>
Date: Mon May 27 15:39:54 2024 +0000

  net/sched: taprio: make q->picos_per_byte available to fill_sched_entry()

  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2025/01/01 linux-5.15.y (ToT) 91786f140358 C [report] INFO: rcu detected stall in cleanup_mnt
2025/01/01 upstream (ToT) ccb98ccef0e5 C Didn't crash
▶ ▼ Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in cleanup_mnt 1 1 1163d 1163d 0/3 auto-obsoleted due to no activity on 2023/09/19 04:00
upstream INFO: rcu detected stall in cleanup_mnt (2) block 1 1 1699d 1699d 0/29 closed as invalid on 2022/02/08 10:10
linux-6.1 INFO: rcu detected stall in cleanup_mnt (2) 1 1 793d 793d 0/3 auto-obsoleted due to no activity on 2024/09/23 19:34
linux-6.1 INFO: rcu detected stall in cleanup_mnt (3) 1 1 427d 427d 0/3 auto-obsoleted due to no activity on 2025/09/24 18:34
upstream INFO: rcu detected stall in cleanup_mnt (5) f2fs 1 12 214d 340d 0/29 auto-obsoleted due to no activity on 2026/04/14 22:36
linux-6.1 INFO: rcu detected stall in cleanup_mnt 1 1 1108d 1108d 0/3 auto-obsoleted due to no activity on 2023/11/13 00:06
upstream INFO: rcu detected stall in cleanup_mnt exfat 1 1 2231d 2231d 0/29 auto-closed as invalid on 2020/09/06 14:28
upstream INFO: rcu detected stall in cleanup_mnt (4) f2fs mm 1 21 439d 796d 0/29 auto-obsoleted due to no activity on 2025/09/02 03:29
upstream INFO: rcu detected stall in cleanup_mnt (3) block fs 1 2 1174d 1185d 0/29 auto-obsoleted due to no activity on 2023/08/29 03:36
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/08/16 06:29 22m retest repro linux-5.15.y report job log log
2026/06/14 21:01 20m retest repro linux-5.15.y report log
2026/06/14 21:01 22m retest repro linux-5.15.y report log
2026/05/21 21:19 20m retest repro linux-5.15.y report log
2026/03/27 20:31 38m retest repro linux-5.15.y report log
2026/03/27 20:31 20m retest repro linux-5.15.y report log
2026/02/20 23:43 12m retest repro linux-5.15.y report log
2026/01/16 13:35 18m retest repro linux-5.15.y report log
2026/01/16 13:35 28m retest repro linux-5.15.y report log
2025/12/12 19:39 15m retest repro linux-5.15.y report log
▶ ▼ Fix bisection attempts (1)
Created Duration User Patch Repo Result
2024/09/30 14:24 8h35m fix candidate upstream OK (1) job log

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (10500 ticks this GP) idle=d7f/1/0x4000000000000000 softirq=6541/6541 fqs=5247 
	(t=10502 jiffies g=7645 q=20072)
NMI backtrace for cpu 1
CPU: 1 PID: 4420 Comm: syz.2.24 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6d8/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1690 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:xfs_icwalk_ag+0x241/0x19a0 fs/xfs/xfs_icache.c:1681
Code: eb 24 e8 72 8a 8a fe c6 05 4e 93 68 0a 01 48 c7 c7 80 8f 43 8a be e5 02 00 00 48 c7 c2 c0 8f 43 8a e8 c3 04 b1 06 8b 54 24 50 <48> 8b bc 24 90 00 00 00 48 8d b4 24 00 01 00 00 b9 20 00 00 00 44
RSP: 0018:ffffc9000398f9a0 EFLAGS: 00000293
RAX: ffffffff82ed4075 RBX: 0000000000000001 RCX: ffff8880229cbb80
RDX: 0000000000000000 RSI: ffffffff8a59a460 RDI: ffffffff8a59a420
RBP: ffffc9000398fc40 R08: dffffc0000000000 R09: fffffbfff1ff7819
R10: fffffbfff1ff7819 R11: 1ffffffff1ff7818 R12: dffffc0000000000
R13: ffff888058545000 R14: 1ffff1100b46b022 R15: dffffc0000000000
 xfs_icwalk fs/xfs/xfs_icache.c:1773 [inline]
 xfs_reclaim_inodes+0x188/0x260 fs/xfs/xfs_icache.c:993
 xfs_unmount_flush_inodes fs/xfs/xfs_mount.c:554 [inline]
 xfs_unmountfs+0x14f/0x250 fs/xfs/xfs_mount.c:1016
 xfs_fs_put_super+0x66/0x2b0 fs/xfs/xfs_super.c:1095
 generic_shutdown_super+0x130/0x300 fs/super.c:475
 kill_block_super+0x7c/0xe0 fs/super.c:1427
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1139
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f60f5ea934a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 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:00007ffc7b1acf48 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffec RBX: 00007ffc7b1acfd0 RCX: 00007f60f5ea934a
RDX: 00002000000002c0 RSI: 0000200000009740 RDI: 00007ffc7b1acf90
RBP: 00002000000002c0 R08: 00007ffc7b1acfd0 R09: 0000000004000000
R10: 0000000004000000 R11: 0000000000000246 R12: 0000200000009740
R13: 00007ffc7b1acf90 R14: 0000000000009838 R15: 00002000000000c0
 </TASK>
sched: RT throttling activated
hrtimer: interrupt took 492817311 ns

Crashes (21):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/17 23:18 linux-5.15.y 43bb85222e53 e2beed91 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2024/12/31 07:43 linux-5.15.y 91786f140358 d3ccff63 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2024/09/01 02:08 linux-5.15.y fa93fa65db6e 1eda0d14 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2026/05/26 11:32 linux-5.15.y 241d66fa280c a3e47276 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2026/05/07 15:34 linux-5.15.y ef251c45f1cd cbf9e0fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2026/04/20 23:10 linux-5.15.y b9d57c40a767 e65da4ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2025/12/18 05:44 linux-5.15.y 68efe5a6c16a d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2025/11/16 10:05 linux-5.15.y cc5ec8769306 f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2025/11/12 03:29 linux-5.15.y cc5ec8769306 4e1406b4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2025/10/08 00:08 linux-5.15.y 29e53a5b1c4f 7e2882b3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2025/09/17 20:16 linux-5.15.y 43bb85222e53 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2025/09/04 04:16 linux-5.15.y 01879f56bdde d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2025/08/28 22:04 linux-5.15.y 01879f56bdde d401b9d7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2025/08/11 00:03 linux-5.15.y c79648372d02 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2025/05/28 12:16 linux-5.15.y 98f47d0e9b8c 874a1386 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2025/05/09 04:40 linux-5.15.y 16fdf2c7111b bb813bcc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2025/01/22 19:12 linux-5.15.y 4735586da88e a44b0418 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2024/12/30 22:33 linux-5.15.y 91786f140358 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2024/10/21 14:05 linux-5.15.y 584a40a22cb9 f1e4447c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2024/09/23 11:34 linux-5.15.y 3a5928702e71 89298aad .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
2024/08/10 23:42 linux-5.15.y 7e89efd3ae1c 6f4edef4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in cleanup_mnt
* Struck through repros no longer work on HEAD.