INFO: rcu detected stall in security_file_open (4)

Status: upstream: reported C repro on 2026/07/25 17:02
Reported-by: syzbot+1058a14501196131c417@syzkaller.appspotmail.com
First crash: 28d, last: 13d
▶ ▼ Similar bugs (12)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in security_file_open (5) tomoyo 1 4 1733d 1843d 0/29 closed as invalid on 2022/02/08 09:50
upstream INFO: rcu detected stall in security_file_open (3) afs 1 syz, C done done 2 2153d 2153d 15/29 fixed on 2020/11/16 12:12
upstream INFO: rcu detected stall in security_file_open mm 1 5 2454d 2455d 0/29 closed as invalid on 2019/12/04 14:04
linux-6.6 INFO: rcu detected stall in security_file_open origin:upstream 1 syz error 5 124d 274d 0/2 upstream: reported syz repro on 2025/11/22 02:38
upstream INFO: rcu detected stall in security_file_open (2) mm 1 2 2419d 2419d 0/29 closed as invalid on 2020/01/08 05:23
linux-6.1 INFO: rcu detected stall in security_file_open 1 1 1068d 1068d 0/3 auto-obsoleted due to no activity on 2023/12/28 22:15
linux-6.1 INFO: rcu detected stall in security_file_open (3) 1 6 171d 363d 0/3 auto-obsoleted due to no activity on 2026/06/12 23:26
linux-5.15 INFO: rcu detected stall in security_file_open (2) origin:upstream 1 syz error 11 1d10h 558d 0/3 upstream: reported syz repro on 2025/02/11 10:29
upstream INFO: rcu detected stall in security_file_open (4) tomoyo 1 1 1952d 1952d 0/29 auto-closed as invalid on 2021/06/18 10:54
linux-6.1 INFO: rcu detected stall in security_file_open (2) 1 1 725d 725d 0/3 auto-obsoleted due to no activity on 2024/12/06 07:18
linux-5.15 INFO: rcu detected stall in security_file_open 1 3 678d 764d 0/3 auto-obsoleted due to no activity on 2025/01/22 08:07
upstream INFO: rcu detected stall in security_file_open (6) tomoyo mm 1 syz, C error 468 1d03h 1153d 0/29 closed as dup on 2023/06/27 10:07

Sample crash report:
rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-.... } 2671 jiffies s: 3633 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: 4323 Comm: udevd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:lock_release+0x5a2/0x920 kernel/locking/lockdep.c:5700
Code: 00 00 00 00 9c 8f 84 24 80 00 00 00 f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 2f 04 f8 75 70 f7 44 24 50 00 02 00 00 74 01 fb <48> c7 44 24 60 0e 36 e0 45 4b c7 04 2f 00 00 00 00 43 c7 44 2f 08
RSP: 0018:ffffc900001e06a0 EFLAGS: 00000046
RAX: 0000000000000001 RBX: 7e8285bf9ccb5258 RCX: f8a4a4448d327800
RDX: 0000000000000002 RSI: ffffffff8a8c2920 RDI: ffffffff8adf5de0
RBP: ffffc900001e07b0 R08: ffffffff8e210aef R09: 1ffffffff1c4215d
R10: dffffc0000000000 R11: fffffbfff1c4215e R12: ffff88801a7ec730
R13: dffffc0000000000 R14: ffff88801a7ec6d0 R15: 1ffff9200003c0e0
FS:  00007fc484baf880(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000140 CR3: 00000000725ce000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_lock_release include/linux/rcupdate.h:355 [inline]
 rcu_read_unlock include/linux/rcupdate.h:824 [inline]
 trace_call_bpf+0x5ca/0x6b0 kernel/trace/bpf_trace.c:137
 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10027
 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728
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 a2 7c 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:ffffc900001e0ae0 EFLAGS: 00000206
RAX: f8a4a4448d327800 RBX: 1ffff9200003c164 RCX: f8a4a4448d327800
RDX: dffffc0000000000 RSI: ffffffff8a8c17a0 RDI: ffffffff8adf5de0
RBP: ffffc900001e0bd0 R08: ffff8880b8f3580b R09: 1ffff110171e6b01
R10: dffffc0000000000 R11: ffffed10171e6b02 R12: 0000000000000246
R13: dffffc0000000000 R14: ffff8880b8f3bb00 R15: 0000000000000002
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:823 [inline]
 ieee80211_iterate_active_interfaces_atomic+0x156/0x170 net/mac80211/util.c:826
 mac80211_hwsim_beacon+0xb7/0x1b0 drivers/net/wireless/mac80211_hwsim.c:2147
 __run_hrtimer kernel/time/hrtimer.c:1751 [inline]
 __hrtimer_run_queues+0x522/0xc90 kernel/time/hrtimer.c:1815
 hrtimer_run_softirq+0x173/0x290 kernel/time/hrtimer.c:1832
 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:bytes_is_nonzero mm/kasan/generic.c:85 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x84/0x290 mm/kasan/generic.c:189
Code: 49 c1 e9 03 4b 8d 1c 21 49 89 df 4d 29 df 49 83 ff 10 7f 29 4d 85 ff 0f 84 38 01 00 00 4c 89 cb 48 f7 d3 4c 01 f3 41 80 3b 00 <0f> 85 86 01 00 00 49 ff c3 48 ff c3 75 ee e9 18 01 00 00 44 89 dd
RSP: 0018:ffffc900040575c0 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffffffffffffffff RCX: ffffffff83d32fb4
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88807e796f30
RBP: ffff88807e796f10 R08: ffff88807e796f37 R09: 1ffff1100fcf2de6
R10: dffffc0000000000 R11: ffffed100fcf2de6 R12: dffffc0000000001
R13: 0000000000000001 R14: 1ffff1100fcf2de6 R15: 0000000000000001
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 tomoyo_check_acl+0x2d4/0x3f0 security/tomoyo/domain.c:184
 tomoyo_path_permission+0x1a6/0x3a0 security/tomoyo/file.c:586
 tomoyo_check_open_permission+0x29b/0x440 security/tomoyo/file.c:777
 security_file_open+0x5e/0xa0 security/security.c:1682
 do_dentry_open+0x2fd/0x10b0 fs/open.c:869
 do_open fs/namei.c:3634 [inline]
 path_openat+0x2674/0x2f10 fs/namei.c:3791
 do_filp_open+0x1ee/0x420 fs/namei.c:3818
 do_sys_openat2+0x14b/0x4f0 fs/open.c:1320
 do_sys_open fs/open.c:1336 [inline]
 __do_sys_openat fs/open.c:1352 [inline]
 __se_sys_openat fs/open.c:1347 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1347
 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: 0033:0x7fc4844a7407
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:00007ffc5b7b7c80 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fc484baf880 RCX: 00007fc4844a7407
RDX: 00000000000a0800 RSI: 000055d80cc995e0 RDI: ffffffffffffff9c
RBP: 000055d80cc98910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055d80ccabe20
R13: 000055d80ccb0410 R14: 0000000000000000 R15: 000055d80ccabe20
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/09 15:57 linux-6.1.y e4f7d8be268e 5d63f80b .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in security_file_open
2026/07/25 17:02 linux-6.1.y dc5c83b7f5f8 492bab15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-perf INFO: rcu detected stall in security_file_open
* Struck through repros no longer work on HEAD.