syzbot

 sign-in | mailing list | source | docs | 🏰
🐞 Open [1355]
≡ Subsystems
🐞 Fixed [7073]
🐞 Invalid [18602]
⬇ Missing Backports [221]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
✨ AI
💬 Send us feedback

INFO: rcu detected stall in sys_mount (8)

Status: upstream: reported C repro on 2025/08/27 13:07
Subsystems: mm
[Documentation on labels]
Reported-by: syzbot+4507914ec56d21bb39ed@syzkaller.appspotmail.com
First crash: 392d, last: 1d12h
Cause bisection: failed (error log, bisect log)
  
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [block?] [ext4?] [btrfs?] INFO: rcu detected stall in sys_mount (8) 1 (3) 2025/08/27 22:06
▶ ▼ Similar bugs (13)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_mount (6) ntfs 1 C inconclusive 82 900d 1674d 0/29 auto-obsoleted due to no activity on 2024/02/18 04:52
upstream INFO: rcu detected stall in sys_mount (4) fs 1 2 2246d 2261d 0/29 auto-closed as invalid on 2020/06/02 15:48
upstream INFO: rcu detected stall in sys_mount (5) afs 1 C done done 10 2036d 2057d 15/29 fixed on 2020/11/16 12:12
linux-5.15 INFO: rcu detected stall in sys_mount 1 2 502d 563d 0/3 auto-obsoleted due to no activity on 2025/03/22 20:11
upstream INFO: rcu detected stall in sys_mount (3) mm 1 6 2337d 2338d 0/29 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in sys_mount nfs 1 1 2743d 2743d 0/29 closed as invalid on 2018/10/29 13:47
upstream INFO: rcu detected stall in sys_mount (7) fs 1 C inconclusive done 41 490d 732d 0/29 auto-obsoleted due to no activity on 2025/03/30 13:11
upstream INFO: rcu detected stall in sys_mount (2) exfat 1 1 2694d 2694d 0/29 closed as dup on 2018/12/12 21:01
linux-5.15 INFO: rcu detected stall in mount origin:lts-only 1 C error 3 293d 358d 0/3 upstream: reported C repro on 2025/05/05 20:18
linux-6.1 INFO: rcu detected stall in sys_mount origin:lts-only 1 C inconclusive 7 110d 499d 0/3 upstream: reported C repro on 2024/12/14 21:36
android-5-15 BUG: soft lockup in sys_mount origin:lts 1 C error 17 663d 740d 0/2 auto-obsoleted due to no activity on 2024/10/17 05:03
upstream INFO: rcu detected stall in __se_sys_mount afs 1 C done done 2 1998d 2122d 15/29 fixed on 2020/12/08 16:15
upstream BUG: soft lockup in sys_mount kernel 1 1 2122d 2122d 0/29 auto-closed as invalid on 2020/10/04 01:38
▶ ▼ Last patch testing requests (4)
Created Duration User Patch Repo Result
2026/04/11 15:36 42m retest repro linux-next OK log
2026/01/31 10:38 24m retest repro linux-next report log
2025/09/10 18:20 39m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2025/08/27 21:38 27m hdanton@sina.com vfs-fixes OK log

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5966/2:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=18293, q=8281 ncpus=2)
task:syz-executor    state:R  running task     stack:20632 pid:5966  tgid:5966  ppid:1      task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x169e/0x54f0 kernel/sched/core.c:7188
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x14f/0x730 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2d7/0x3c0 kernel/locking/lockdep.c:5895
Code: 42 d6 10 00 00 00 00 eb b5 e8 05 41 96 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 e5 fb d5 10 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 4a 05 9a 09 cc 48 8d 3d 32 d2 ef
RSP: 0018:ffffc90004057b78 EFLAGS: 00000286
RAX: 419ac6e44834ba00 RBX: 0000000000000206 RCX: 0000000000000046
RDX: 00000000250c0f6a RSI: ffffffff8d8b42f4 RDI: ffffffff8ba845e0
RBP: ffff88802b9ce8d8 R08: ffffffff8b393780 R09: ffffffff8dfc8140
R10: 0000000000000000 R11: fffffbfff1f1a8bf R12: 0000000000000005
R13: 0000000000000005 R14: ffff888044292ed0 R15: ffff88802b9cdc40
 rt_spin_unlock+0x29/0x200 kernel/locking/spinlock_rt.c:80
 spin_unlock include/linux/spinlock_rt.h:109 [inline]
 d_set_mounted+0xac/0x220 fs/dcache.c:1529
 get_mountpoint+0x2e1/0x510 fs/namespace.c:897
 do_lock_mount+0x56a/0x960 fs/namespace.c:2777
 do_loopback+0x286/0x6c0 fs/namespace.c:3012
 do_mount fs/namespace.c:4167 [inline]
 __do_sys_mount fs/namespace.c:4383 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4360
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbb95a6da8a
RSP: 002b:00007ffeb9102678 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fbb95b026d5 RCX: 00007fbb95a6da8a
RDX: 0000000000000000 RSI: 00007fbb95ad7478 RDI: 00007fbb95b028d8
RBP: 00007fbb95ad74c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000045000 R11: 0000000000000246 R12: 00007fbb95ad74a0
R13: 00007fbb95ad7478 R14: 00007ffeb91028e8 R15: 0000000000000000
 </TASK>

Crashes (30):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/22 08:50 linux-next bee6ea30c487 0b6ab7ec .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in mount
2026/04/27 08:22 upstream 20b64cf8705a 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_mount
2026/01/17 01:41 upstream 983d014aafb1 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_mount
2025/12/18 04:24 upstream ea1013c15392 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_mount
2025/12/12 02:42 upstream d358e5254674 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_mount
2025/06/29 09:23 upstream aaf724ed6926 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_mount
2025/06/09 16:29 upstream 19272b37aa4f 4826c28e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_mount
2025/04/01 16:36 upstream 08733088b566 d863cf4b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_mount
2026/04/14 22:45 upstream d60bc1401583 362d1323 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in mount
2025/12/05 05:09 upstream 2aa680df6806 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in mount
2025/09/25 23:04 upstream bf40f4b87761 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in mount
2025/08/27 14:14 upstream fab1beda7597 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in mount
2025/08/11 20:49 upstream 8f5ae30d69d7 32a0e5ed .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in mount
2025/07/13 20:42 upstream 5d5d62298b8b 3cda49cf .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in mount
2025/07/03 19:27 upstream 17bbde2e1716 115ceea7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs INFO: rcu detected stall in mount
2025/06/20 08:30 upstream 75f5f23f8787 ed3e87f7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in mount
2025/05/14 14:54 upstream 9f35e33144ae a4fa04ef .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root INFO: rcu detected stall in mount
2025/04/21 03:14 upstream 6fea5fabd332 2a20f901 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in mount
2025/11/03 06:52 upstream 6146a0f1dfae 2c50b6a9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: rcu detected stall in mount
2026/02/09 21:42 bpf 05f7e89ab973 df949cd9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-kasan-gce BUG: soft lockup in mount
2026/01/17 08:58 linux-next 46fe65a2c28e d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in mount
2026/01/01 12:25 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 mount
2026/01/01 11:01 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 mount
2025/12/24 11:26 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 mount
2025/12/14 05:42 linux-next d9771d0dbe18 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in mount
2025/11/22 22:18 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 mount
2025/09/15 19:53 linux-next 590b221ed425 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in mount
2026/01/05 14:24 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f0b4cce4481 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: soft lockup in sys_mount
2025/08/27 09:13 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 e12e5ba4 .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 BUG: soft lockup in sys_mount
2025/08/27 05:23 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 e12e5ba4 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: soft lockup in sys_mount
* Struck through repros no longer work on HEAD.