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INFO: rcu detected stall in sys_umount (3)

Status: upstream: reported C repro on 2024/12/08 08:40
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+1ec0f904ba50d06110b1@syzkaller.appspotmail.com
First crash: 441d, last: 9d22h
Cause bisection: introduced by (bisect log) :
commit d15121be7485655129101f3960ae6add40204463
Author: Paolo Abeni <pabeni@redhat.com>
Date: Mon May 8 06:17:44 2023 +0000

  Revert "softirq: Let ksoftirqd do its job"

Crash: INFO: task hung in devlink_pernet_pre_exit (log)
Repro: syz .config
  
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [mm?] INFO: rcu detected stall in sys_umount (3) 2 (6) 2025/08/19 02:06
▶ ▼ Similar bugs (6)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_umount (2) fs 1 1 1255d 1255d 0/29 auto-closed as invalid on 2022/06/20 00:56
linux-6.1 INFO: rcu detected stall in sys_umount origin:lts-only 1 C inconclusive 1 95d 95d 0/3 upstream: reported C repro on 2025/05/25 02:36
linux-5.15 INFO: rcu detected stall in sys_umount (2) 1 1 125d 125d 0/3 auto-obsoleted due to no activity on 2025/08/02 13:13
linux-5.15 INFO: rcu detected stall in sys_umount 1 1 437d 437d 0/3 auto-obsoleted due to no activity on 2024/09/25 03:07
upstream INFO: rcu detected stall in sys_umount mm 1 8 2226d 2230d 0/29 auto-closed as invalid on 2019/10/25 14:21
linux-6.6 INFO: rcu detected stall in sys_umount 1 1 27d 27d 0/2 upstream: reported on 2025/07/31 23:39
▶ ▼ Last patch testing requests (3)
Created Duration User Patch Repo Result
2025/08/18 22:27 2h13m hdanton@sina.com vfs-fixes OK log
2025/07/12 03:19 1h15m retest repro upstream report log
2025/02/01 09:23 20m retest repro upstream report log
▶ ▼ Fix bisection attempts (2)
Created Duration User Patch Repo Result
2025/03/31 13:36 3h45m bisect fix upstream OK (0) job log log
2025/02/27 15:36 2h26m bisect fix upstream OK (0) job log log

Sample crash report:
watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [syz-executor:6662]
Modules linked in:
irq event stamp: 355416
hardirqs last  enabled at (355415): [<ffff80008b00487c>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:86 [inline]
hardirqs last  enabled at (355415): [<ffff80008b00487c>] exit_to_kernel_mode+0xc0/0xf0 arch/arm64/kernel/entry-common.c:96
hardirqs last disabled at (355416): [<ffff80008b001cbc>] __el1_irq arch/arm64/kernel/entry-common.c:650 [inline]
hardirqs last disabled at (355416): [<ffff80008b001cbc>] el1_interrupt+0x24/0x54 arch/arm64/kernel/entry-common.c:668
softirqs last  enabled at (355404): [<ffff8000803d88a0>] softirq_handle_end kernel/softirq.c:425 [inline]
softirqs last  enabled at (355404): [<ffff8000803d88a0>] handle_softirqs+0xaf8/0xc88 kernel/softirq.c:607
softirqs last disabled at (355387): [<ffff800080022028>] __do_softirq+0x14/0x20 kernel/softirq.c:613
CPU: 1 UID: 0 PID: 6662 Comm: syz-executor Not tainted 6.17.0-rc1-syzkaller-g8f5ae30d69d7 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : propagation_source fs/pnode.c:77 [inline]
pc : change_mnt_propagation+0xec/0x77c fs/pnode.c:114
lr : propagation_source fs/pnode.c:78 [inline]
lr : change_mnt_propagation+0x120/0x77c fs/pnode.c:114
sp : ffff8000a4a07a90
x29: ffff8000a4a07ac0 x28: dfff800000000000 x27: ffff0000efa88b60
x26: ffff0000efa88bb0 x25: 1fffe0001df51176 x24: ffff0000efa88b18
x23: ffff0000f331b238 x22: ffff0000efa88a80 x21: ffff0000efa88a80
x20: 0000000000040000 x19: ffff0000f3339500 x18: 1fffe000337a0688
x17: ffff80008f7be000 x16: ffff80008af6de48 x15: 0000000000000002
x14: 1fffe0001df5116f x13: 0000000000000000 x12: 0000000000000000
x11: ffff60001df51171 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : ffff0000f33395b8 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000001 x4 : 0000000000000008 x3 : 0000000000000000
x2 : 0000000000000008 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
 next_peer fs/pnode.c:19 [inline] (P)
 propagation_source fs/pnode.c:77 [inline] (P)
 change_mnt_propagation+0xec/0x77c fs/pnode.c:114 (P)
 umount_tree+0x7e4/0xbbc fs/namespace.c:1872
 do_umount fs/namespace.c:-1 [inline]
 path_umount+0x90c/0x980 fs/namespace.c:2095
 ksys_umount fs/namespace.c:2118 [inline]
 __do_sys_umount fs/namespace.c:2123 [inline]
 __se_sys_umount fs/namespace.c:2121 [inline]
 __arm64_sys_umount+0x128/0x174 fs/namespace.c:2121
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6746 Comm: syz-executor Not tainted 6.17.0-rc1-syzkaller-g8f5ae30d69d7 #0 PREEMPT 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--)
pc : cpu_relax arch/arm64/include/asm/vdso/processor.h:12 [inline]
pc : path_init+0xdc0/0xe98 fs/namei.c:2537
lr : path_init+0xdc0/0xe98 fs/namei.c:2537
sp : ffff8000a4247680
x29: ffff8000a42476e0 x28: dfff800000000000 x27: 1fffe00019832884
x26: ffff0000cc194420 x25: 0000000000000101 x24: 1ffff00014848f43
x23: ffff80008f745840 x22: ffff8000a4247a1c x21: 0000000000000100
x20: ffff8000a42479e0 x19: 000000000004a017 x18: 0000000000000000
x17: 0000000000000000 x16: ffff80008b007230 x15: 0000000000000001
x14: 1ffff00011ee8b08 x13: 0000000000000000 x12: 0000000000000000
x11: ffff700011ee8b09 x10: 0000000000ff0100 x9 : 0000000000000000
x8 : ffff0000da1e0000 x7 : ffff800080daa4c4 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080da8a84
x2 : 0000000000000000 x1 : 0000000000000004 x0 : 0000000000000001
Call trace:
 path_init+0xdc0/0xe98 fs/namei.c:2537 (P)
 path_openat+0x13c/0x2c40 fs/namei.c:4041
 do_filp_open+0x18c/0x36c fs/namei.c:4073
 do_open_execat+0x124/0x4d8 fs/exec.c:783
 alloc_bprm+0x3c/0x548 fs/exec.c:1410
 do_execveat_common+0x168/0x834 fs/exec.c:1811
 do_execve fs/exec.c:1934 [inline]
 __do_sys_execve fs/exec.c:2010 [inline]
 __se_sys_execve fs/exec.c:2005 [inline]
 __arm64_sys_execve+0x9c/0xb4 fs/exec.c:2005
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
 el0_svc+0x58/0x180 arch/arm64/kernel/entry-common.c:879
 el0t_64_sync_handler+0x84/0x12c arch/arm64/kernel/entry-common.c:898
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:596

Crashes (43):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/18 09:41 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 1804e95e .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci-upstream-gce-arm64 BUG: soft lockup in sys_umount
2024/12/04 08:30 upstream feffde684ac2 b50eb251 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in sys_umount
2025/07/29 08:48 upstream ced1b9e0392d c4a95487 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_umount
2025/06/28 01:26 upstream 35e261cd95dd 803ce19b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_umount
2025/06/14 15:44 upstream 4774cfe3543a 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_umount
2025/06/07 02:23 upstream 7a912d04415b f61267d4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_umount
2025/03/01 13:31 upstream 7a5668899f54 1e7a43e1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in sys_umount
2025/01/11 09:56 upstream 77a903cd8e5a 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in sys_umount
2025/01/05 21:40 upstream ab75170520d4 f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in sys_umount
2024/12/29 22:06 upstream 4099a71718b0 d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_umount
2024/12/20 10:02 upstream 8faabc041a00 1d58202c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_umount
2024/12/19 12:04 upstream eabcdba3ad40 1432fc84 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_umount
2024/12/19 10:52 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_umount
2024/12/08 18:18 upstream 7503345ac5f5 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in sys_umount
2024/12/04 01:48 upstream feffde684ac2 b50eb251 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_umount
2024/12/01 12:22 upstream bcc8eda6d349 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_umount
2024/11/11 03:25 upstream a9cda7c0ffed 6b856513 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in sys_umount
2024/11/05 04:23 upstream 557329bcecc2 509da429 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in sys_umount
2024/10/23 09:10 upstream c2ee9f594da8 15fa2979 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_umount
2024/10/15 08:32 upstream eca631b8fe80 b01b6661 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_umount
2024/09/24 03:02 upstream abf2050f51fd 89298aad .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_umount
2024/07/22 19:01 upstream 933069701c1b f063dfd9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_umount
2024/07/16 18:20 upstream d67978318827 215bec2d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_umount
2024/06/25 00:55 upstream 626737a5791b 215eef4a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_umount
2024/06/13 06:53 upstream cea2a26553ac 2aa5052f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_umount
2025/05/09 19:30 upstream 9c69f8884904 bb813bcc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: rcu detected stall in sys_umount
2025/08/03 07:57 net 1dbf1d590d10 7368264b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_umount
2025/01/16 12:00 net cbc16bceea78 968edaf4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_umount
2025/01/13 01:14 net 47e55e4b410f 6dbc6a9b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_umount
2025/01/06 02:15 net 8ce4f287524c f3558dbf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_umount
2024/12/08 01:02 net 0f6ede9fbc74 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_umount
2024/11/28 01:38 net 5dfd7d940094 5df23865 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_umount
2024/11/16 10:35 net ea301aec8bb7 cfe3a04a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_umount
2024/11/11 23:21 net 252e01e68241 97fe5517 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_umount
2024/11/10 20:44 net 252e01e68241 6b856513 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_umount
2024/10/11 16:46 net 1d227fcc7222 cd942402 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_umount
2024/10/02 15:02 net c4a14f6d9d17 a4c7fd36 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_umount
2025/01/17 22:14 net-next 8d20dcda404d 953d1c45 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in sys_umount
2025/01/15 11:35 net-next 7a1723d3b230 7315a7cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in sys_umount
2024/11/28 17:26 linux-next f486c8aa16b8 5df23865 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_umount
2024/10/31 02:21 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing c67e9601e29a 96eb609f .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in sys_umount
2024/10/27 05:41 https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing c6d9e43954bf 65e8686b .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-usb INFO: rcu detected stall in sys_umount
2025/08/18 05:33 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: soft lockup in sys_umount
* Struck through repros no longer work on HEAD.