INFO: rcu detected stall in sys_unlink (2)

Status: upstream: reported C repro on 2025/03/27 11:38
Reported-by: syzbot+a0dc8f91386bb1406734@syzkaller.appspotmail.com
First crash: 570d, last: 13d
▶ ▼ Similar bugs (11)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in sys_unlink (4) 1 1 564d 564d 0/3 auto-obsoleted due to no activity on 2025/07/10 21:02
linux-5.15 INFO: rcu detected stall in sys_unlink (3) 1 1 713d 713d 0/3 auto-obsoleted due to no activity on 2025/02/11 14:08
upstream INFO: rcu detected stall in sys_unlink (2) kernel 1 2 1364d 1449d 0/29 auto-obsoleted due to no activity on 2023/04/22 20:06
upstream INFO: rcu detected stall in sys_unlink (3) mm 1 syz, C error 449 21h09m 1161d 0/29 upstream: reported C repro on 2023/08/13 23:42
linux-5.15 INFO: rcu detected stall in sys_unlink (5) 1 18 14d 387d 0/3 upstream: reported on 2025/09/25 16:42
linux-6.1 INFO: rcu detected stall in sys_unlink 1 4 780d 999d 0/3 auto-obsoleted due to no activity on 2024/12/07 03:28
linux-5.15 INFO: rcu detected stall in sys_unlink (2) 1 3 833d 844d 0/3 auto-obsoleted due to no activity on 2024/10/15 13:02
linux-6.6 INFO: rcu detected stall in sys_unlink 1 53 4d11h 454d 0/2 upstream: reported on 2025/07/20 18:19
upstream INFO: rcu detected stall in sys_unlink mm kasan 1 1 1540d 1540d 0/29 auto-obsoleted due to no activity on 2022/10/29 07:23
linux-5.15 INFO: rcu detected stall in sys_unlink 1 1 949d 949d 0/3 auto-obsoleted due to no activity on 2024/06/20 14:47
android-5-15 BUG: soft lockup in sys_unlink 1 7 892d 914d 0/2 auto-obsoleted due to no activity on 2024/08/07 01:29

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2656 jiffies s: 3733 root: 0x2/.
rcu: blocking rcu_node structures (internal RCU debug):
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4408 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:asm_sysvec_irq_work+0x0/0x20 arch/x86/include/asm/idtentry.h:722
Code: e9 b5 03 00 00 90 90 90 90 90 0f 01 ca fc 6a ff e8 b5 02 00 00 48 89 c4 48 89 e7 e8 9a 84 f3 ff e9 95 03 00 00 90 90 90 90 90 <0f> 01 ca fc 6a ff e8 95 02 00 00 48 89 c4 48 89 e7 e8 6a 89 f3 ff
RSP: 0018:ffffc900001e0738 EFLAGS: 00000006
RAX: dd20639e6e4d9700 RBX: 1ffff9200003c0f4 RCX: dd20639e6e4d9700
RDX: dffffc0000000000 RSI: ffffffff8a8c18a0 RDI: ffffffff8adf6de0
RBP: ffffc900001e0860 R08: ffffffff90b3334f R09: 1ffffffff2166669
R10: dffffc0000000000 R11: fffffbfff216666a R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3bb00 R15: 0000000000000002
FS:  000055558bbdf500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc17ee1ff0 CR3: 000000005c0e9000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 d2 68 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900001e0760 EFLAGS: 00000206
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 ndisc_send_skb+0xdc2/0x1520 net/ipv6/ndisc.c:521
 addrconf_rs_timer+0x367/0x640 net/ipv6/addrconf.c:3994
 call_timer_fn+0x1ac/0x670 kernel/time/timer.c:1701
 expire_timers kernel/time/timer.c:1752 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:2023
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:2036
 handle_softirqs+0x291/0x910 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:kasan_quarantine_put+0x84/0x210 mm/kasan/quarantine.c:245
Code: e8 01 06 b5 ff 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 0f 85 83 00 00 00 41 f7 c7 00 02 00 00 74 01 fb 31 c0 <48> 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f c3 48 8d 80 c0 66 03 00 45
RSP: 0018:ffffc90003207a08 EFLAGS: 00000206
RAX: dd20639e6e4d9701 RBX: ffff88801b6f9000 RCX: dd20639e6e4d9700
RDX: dffffc0000000000 RSI: ffffffff8a8c18a0 RDI: ffffffff8adf6de0
RBP: ffff88801b6f9000 R08: ffffffff90b332e7 R09: 1ffffffff216665c
R10: dffffc0000000000 R11: fffffbfff216665d R12: 0000000000000000
R13: ffffc90003207aa0 R14: 0000000000051780 R15: 0000000000000286
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1729 [inline]
 slab_free_freelist_hook+0x133/0x1b0 mm/slub.c:1755
 slab_free mm/slub.c:3687 [inline]
 __kmem_cache_free+0xb6/0x200 mm/slub.c:3700
 tomoyo_path_perm+0x48c/0x610 security/tomoyo/file.c:842
 tomoyo_path_unlink+0xa7/0xf0 security/tomoyo/tomoyo.c:149
 security_path_unlink+0xd8/0x130 security/security.c:1193
 do_unlinkat+0x2af/0x580 fs/namei.c:4437
 __do_sys_unlink fs/namei.c:4489 [inline]
 __se_sys_unlink fs/namei.c:4487 [inline]
 __x64_sys_unlink+0x45/0x50 fs/namei.c:4487
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ffad279d247
Code: 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 57 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 e8 ff ff ff f7 d8 64 89 02 b8
RSP: 002b:00007ffc17ee2648 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ffad279d247
RDX: 00007ffc17ee2670 RSI: 00007ffc17ee2700 RDI: 00007ffc17ee2700
RBP: 00007ffc17ee2700 R08: 00007ffc17ee3700 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffc17ee3790
R13: 00007ffad28344bb R14: 000000000001aa84 R15: 00007ffc17ee37d0
 </TASK>

Crashes (38):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/10/04 15:40 linux-6.1.y a500ba24937a 57bbd979 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sys_unlink
2026/09/21 22:37 linux-6.1.y 1a8763b93150 853b104b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/09/17 22:31 linux-6.1.y 1a8763b93150 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/09/17 20:40 linux-6.1.y 1a8763b93150 8d7d05f1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/09/07 20:48 linux-6.1.y cf82dcca9634 680aa3e1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/09/07 10:39 linux-6.1.y cf82dcca9634 4f7b22a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/08/18 11:08 linux-6.1.y e4f7d8be268e 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/08/14 14:58 linux-6.1.y e4f7d8be268e 6f9b3e89 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/07/30 22:07 linux-6.1.y fb28aa725e05 aaffb173 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/07/27 06:13 linux-6.1.y dc5c83b7f5f8 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/07/09 09:36 linux-6.1.y 090666d3cc90 b9f1ceaa .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/05/30 11:03 linux-6.1.y dcbcab9d7079 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/05/21 17:47 linux-6.1.y c27210688955 e195359d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/05/10 08:07 linux-6.1.y ad16b162f21d 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/04/15 23:03 linux-6.1.y 8e8fc038cad5 c441f497 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/02/24 20:57 linux-6.1.y 779f9571ac3e 96b1aa46 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/02/21 03:34 linux-6.1.y 779f9571ac3e 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/02/12 10:28 linux-6.1.y 8ce36b2849ef 76a109e2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/02/10 17:51 linux-6.1.y 0182cb5b74ee 91d776d3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/02/01 14:55 linux-6.1.y cd9b81672742 6b8752f2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/01/31 23:55 linux-6.1.y cd9b81672742 afc0c4d4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/01/31 23:53 linux-6.1.y cd9b81672742 afc0c4d4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/01/31 23:48 linux-6.1.y cd9b81672742 afc0c4d4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/01/27 21:55 linux-6.1.y cd9b81672742 9a514c2f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/01/27 21:48 linux-6.1.y cd9b81672742 9a514c2f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2026/01/26 20:41 linux-6.1.y cd9b81672742 a4c52dd6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2025/12/10 18:37 linux-6.1.y 50cbba13faa2 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2025/11/05 11:26 linux-6.1.y f6e38ae624cf a6c9c731 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2025/10/30 12:43 linux-6.1.y f6e38ae624cf fd2207e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2025/10/25 09:55 linux-6.1.y 8e6e2188d949 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2025/09/24 01:47 linux-6.1.y 363a599da6d9 e667a34f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2025/09/20 02:49 linux-6.1.y 363a599da6d9 67c37560 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2025/09/10 06:06 linux-6.1.y f97f1002271b fdeaa69b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2025/09/08 18:04 linux-6.1.y 28c695c365e1 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2025/08/07 20:45 linux-6.1.y 3594f306da12 04cffc22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2025/05/07 14:34 linux-6.1.y ac7079a42ea5 350f4ffc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in sys_unlink
2025/04/10 09:45 linux-6.1.y 3dfebb87d7eb 988b336c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
2025/03/27 11:38 linux-6.1.y 344a09659766 20510e88 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in sys_unlink
* Struck through repros no longer work on HEAD.