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INFO: rcu detected stall in sys_wait4 (6)

Status: auto-obsoleted due to no activity on 2025/10/04 12:51
Subsystems: fs
[Documentation on labels]
First crash: 169d, last: 97d
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_wait4 (3) kernel 1 1 777d 777d 0/29 auto-obsoleted due to no activity on 2023/11/24 01:26
upstream INFO: rcu detected stall in sys_wait4 (2) kernel 1 1 1286d 1286d 0/29 auto-closed as invalid on 2022/07/03 11:21
upstream INFO: rcu detected stall in sys_wait4 (4) mm 1 C done done 2 515d 547d 26/29 fixed on 2024/07/12 01:55
upstream INFO: rcu detected stall in sys_wait4 kernel 1 1 1917d 1917d 0/29 auto-closed as invalid on 2020/10/10 08:00
linux-5.15 INFO: rcu detected stall in sys_wait4 1 1 485d 485d 0/3 auto-obsoleted due to no activity on 2024/09/21 03:35
upstream INFO: rcu detected stall in sys_wait4 (5) kernel 1 1 289d 289d 0/29 auto-obsoleted due to no activity on 2025/03/26 13:51
linux-6.1 INFO: rcu detected stall in sys_wait4 1 1 914d 914d 0/3 auto-obsoleted due to no activity on 2023/08/09 13:38

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P8717/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=82717, q=1186784 ncpus=2)
task:syz-executor    state:S stack:22008 pid:8717  tgid:8717  ppid:8694   task_flags:0x400140 flags:0x00000002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5870
Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 1b b3 f9 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc9000c22ec38 EFLAGS: 00000206
RAX: 545670e300205400 RBX: 0000000000000000 RCX: 545670e300205400
RDX: 0000000000000000 RSI: ffffffff8db42415 RDI: ffffffff8be1ba80
RBP: ffffffff8171a9f5 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8171a9f5 R12: 0000000000000002
R13: ffffffff8e13b860 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4161 [inline]
 slab_alloc_node mm/slub.c:4210 [inline]
 kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4217
 kmem_alloc_batch lib/debugobjects.c:371 [inline]
 fill_pool+0x100/0x570 lib/debugobjects.c:403
 debug_objects_fill_pool lib/debugobjects.c:725 [inline]
 debug_object_activate+0x383/0x420 lib/debugobjects.c:814
 debug_rcu_head_queue kernel/rcu/rcu.h:224 [inline]
 __call_rcu_common kernel/rcu/tree.c:3067 [inline]
 call_rcu+0x95/0x990 kernel/rcu/tree.c:3202
 __destroy_inode+0x2da/0x670 fs/inode.c:371
 destroy_inode fs/inode.c:394 [inline]
 evict+0x797/0x9c0 fs/inode.c:834
 __dentry_kill+0x209/0x660 fs/dcache.c:660
 shrink_kill+0xa9/0x2c0 fs/dcache.c:1105
 shrink_dentry_list+0x2e0/0x5e0 fs/dcache.c:1132
 shrink_dcache_parent+0xa1/0x2c0 fs/dcache.c:-1
 d_invalidate+0x11b/0x260 fs/dcache.c:1649
 proc_invalidate_siblings_dcache+0x3d3/0x6c0 fs/proc/inode.c:142
 release_task+0x120e/0x17f0 kernel/exit.c:285
 wait_task_zombie kernel/exit.c:1264 [inline]
 wait_consider_task+0x195a/0x2e60 kernel/exit.c:1491
 do_wait_thread kernel/exit.c:1554 [inline]
 __do_wait+0x153/0x740 kernel/exit.c:1672
 do_wait+0x1f8/0x520 kernel/exit.c:1706
 kernel_wait4+0x1af/0x280 kernel/exit.c:1865
 __do_sys_wait4 kernel/exit.c:1893 [inline]
 __se_sys_wait4 kernel/exit.c:1889 [inline]
 __x64_sys_wait4+0x133/0x1e0 kernel/exit.c:1889
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faa04d84bd7
RSP: 002b:00007faa050dfd80 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 000000000000039f RCX: 00007faa04d84bd7
RDX: 0000000040000001 RSI: 00007faa050dfdec RDI: 00000000ffffffff
RBP: 00007faa050dfdec R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000128
R13: 0000000000000061 R14: 00000000000ae034 R15: 00007faa050dfe40
 </TASK>

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/25 11:30 upstream 02ddfb981de8 e3715315 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in sys_wait4
2025/07/06 12:46 net b9fd9888a565 4f67c4ae .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-this-kasan-gce INFO: rcu detected stall in sys_wait4
* Struck through repros no longer work on HEAD.