syzbot

 sign-in | mailing list | source | docs
🐞 Open [1445]
≡ Subsystems
🐞 Fixed [6881]
🐞 Invalid [17863]
⬇ Missing Backports [224]
≡ Crashes
Kernel Health Bugs/Month Bug Lifetimes Fuzzing
Total Repo Heatmap Subsystems Heatmap
💬 Send us feedback

INFO: rcu detected stall in wait4 (7)

Status: auto-obsoleted due to no activity on 2026/01/14 18:39
Subsystems: kernel
[Documentation on labels]
First crash: 98d, last: 98d
▶ ▼ Similar bugs (7)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in wait4 (3) kernel 1 2 1075d 1080d 0/29 auto-obsoleted due to no activity on 2023/05/14 12:43
upstream INFO: rcu detected stall in wait4 kernel 1 2 1692d 1748d 0/29 auto-closed as invalid on 2021/09/04 10:15
upstream INFO: rcu detected stall in wait4 (5) fs 1 6 448d 479d 0/29 auto-obsoleted due to no activity on 2025/01/30 05:34
upstream INFO: rcu detected stall in wait4 (4) kernel 1 C error done 35 592d 920d 0/29 auto-obsoleted due to no activity on 2024/09/18 16:22
upstream INFO: rcu detected stall in wait4 (2) kernel 1 2 1277d 1358d 0/29 auto-obsoleted due to no activity on 2022/10/24 16:24
upstream INFO: rcu detected stall in wait4 (6) kernel 1 1 329d 329d 0/29 auto-obsoleted due to no activity on 2025/05/29 01:55
upstream INFO: rcu detected stall in __do_sys_wait4 kernel 1 2 1959d 1989d 0/29 auto-closed as invalid on 2020/12/11 15:32

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P26772/1:b..l P29561/1:b..l P30459/1:b..l P21628/1:b..l P24070/1:b..l P26989/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=156305, q=1278 ncpus=2)
task:syz-executor    state:S stack:23992 pid:26989 tgid:26989 ppid:26969  task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:kasan_byte_accessible+0x15/0x30 mm/kasan/generic.c:210
Code: 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 b8 00 00 00 00 00 fc ff df 48 c1 ef 03 48 01 c7 <0f> b6 07 3c 07 0f 96 c0 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00
RSP: 0018:ffffc9000c4d7490 EFLAGS: 00000282
RAX: dffffc0000000000 RBX: ffffffff8e3c4460 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff816c45f1 RDI: fffffbfff1c7888c
RBP: ffffffff8e3c4460 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000007d30 R12: ffffffff816c45f1
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 __kasan_check_byte+0x13/0x50 mm/kasan/common.c:579
 kasan_check_byte include/linux/kasan.h:401 [inline]
 lock_acquire kernel/locking/lockdep.c:5842 [inline]
 lock_acquire+0xfc/0x350 kernel/locking/lockdep.c:5825
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
 kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:559
 __call_rcu_common.constprop.0+0xa5/0xa10 kernel/rcu/tree.c:3123
 free_pids+0x45/0x80 kernel/pid.c:160
 release_task+0xe33/0x1ca0 kernel/exit.c:296
 wait_task_zombie kernel/exit.c:1269 [inline]
 wait_consider_task+0x1756/0x3eb0 kernel/exit.c:1496
 do_wait_thread kernel/exit.c:1559 [inline]
 __do_wait+0x1e2/0x890 kernel/exit.c:1677
 do_wait+0x21d/0x590 kernel/exit.c:1711
 kernel_wait4+0x16b/0x280 kernel/exit.c:1870
 __do_sys_wait4+0x15d/0x170 kernel/exit.c:1898
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f90a5385017
RSP: 002b:00007ffd3d698120 EFLAGS: 00000293 ORIG_RAX: 000000000000003d
RAX: ffffffffffffffda RBX: 0000000000000277 RCX: 00007f90a5385017
RDX: 0000000040000000 RSI: 00007ffd3d69818c RDI: 00000000ffffffff
RBP: 00007ffd3d69818c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000000000c8
R13: 000055557a02b590 R14: 000000000019d213 R15: 00007ffd3d6981e0
 </TASK>
task:kworker/1:11    state:R  running task     stack:22760 pid:24070 tgid:24070 ppid:2      task_flags:0x4208160 flags:0x00080000
Workqueue: events send_dm_alert
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: 57 0b 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 a2 14 ea 0e 0f 82 74 02 00 00 8b 35 1a 45 ea 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 b9 56 0b 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc900055675d8 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c4460 RCX: 0000000004b28092
RDX: 0000000000000000 RSI: ffffffff8dadd953 RDI: ffffffff8bf1e3c0
RBP: 0000000000000002 R08: 117d1e24d7c214e7 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 discard_slab mm/slub.c:3310 [inline]
 __put_partials+0x130/0x170 mm/slub.c:3857
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:408
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __do_kmalloc_node mm/slub.c:5627 [inline]
 __kmalloc_node_track_caller_noprof+0x345/0x8a0 mm/slub.c:5736
 kmalloc_reserve+0xef/0x2c0 net/core/skbuff.c:601
 __alloc_skb+0x166/0x380 net/core/skbuff.c:670
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 genlmsg_new include/net/genetlink.h:611 [inline]
 reset_per_cpu_data+0x26/0x240 net/core/drop_monitor.c:146
 send_dm_alert+0x1e/0xf0 net/core/drop_monitor.c:197
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3427
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
task:syz-executor    state:R  running task     stack:23936 pid:21628 tgid:21628 ppid:21616  task_flags:0x400140 flags:0x00080001
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: 57 0b 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 a2 14 ea 0e 0f 82 74 02 00 00 8b 35 1a 45 ea 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 b9 56 0b 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc9000cb87218 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c4460 RCX: 000000005d8c4f07
RDX: 0000000000000000 RSI: ffffffff8dadd953 RDI: ffffffff8bf1e3c0
RBP: 0000000000000002 R08: e961e82f35118670 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 discard_slab mm/slub.c:3310 [inline]
 __put_partials+0x130/0x170 mm/slub.c:3857
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:408
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __do_kmalloc_node mm/slub.c:5627 [inline]
 __kmalloc_noprof+0x32f/0x880 mm/slub.c:5639
 kmalloc_noprof include/linux/slab.h:961 [inline]
 tomoyo_realpath_from_path+0xc2/0x6e0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x2ab/0x3c0 security/tomoyo/file.c:771
 tomoyo_file_open+0x6b/0x90 security/tomoyo/tomoyo.c:334
 security_file_open+0x84/0x1e0 security/security.c:3183
 do_dentry_open+0x596/0x1530 fs/open.c:942
 vfs_open+0x82/0x3f0 fs/open.c:1097
 do_open fs/namei.c:3975 [inline]
 path_openat+0x1de4/0x2cb0 fs/namei.c:4134
 do_filp_open+0x20b/0x470 fs/namei.c:4161
 do_sys_openat2+0x11b/0x1d0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0x174/0x210 fs/open.c:1463
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff7cb18e7c1
RSP: 002b:00007ffe7ae3abd0 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ff7cb211d7d RCX: 00007ff7cb18e7c1
RDX: 0000000000090800 RSI: 00007ffe7ae3bde0 RDI: 00000000ffffff9c
RBP: 00007ffe7ae3bde0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000287 R12: 00007ffe7ae3bde0
R13: 00007ff7cb211d7d R14: 000000000019bf3d R15: 00007ffe7ae3ceb0
 </TASK>
task:syz.5.6972      state:R  running task     stack:27480 pid:30459 tgid:30459 ppid:21202  task_flags:0x40044c flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5945
Code: 00 00 b8 ff ff ff ff 65 0f c1 05 fc 9a 3e 08 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 45 31 ed eb
RSP: 0018:ffffc90004887860 EFLAGS: 00000296
RAX: 0000000000000046 RBX: ffff888026e08b30 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8dadd953 RDI: ffffffff8bf1e3c0
RBP: ffffffff8e3c4460 R08: 0000000000000006 R09: 0000000000001000
R10: 0000000000000000 R11: 0000000000000001 R12: ffff888026e08000
R13: 0000000000000001 R14: 00000000ffffffff R15: 0000000000000000
 lookup_page_ext+0x10d/0x1d0 mm/page_ext.c:254
 page_ext_iter_begin include/linux/page_ext.h:132 [inline]
 __page_table_check_zero+0x1a4/0x5d0 mm/page_table_check.c:139
 page_table_check_free include/linux/page_table_check.h:43 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0x7d0/0x1160 mm/page_alloc.c:2906
 vfree+0x1fd/0xb50 mm/vmalloc.c:3440
 kcov_put kernel/kcov.c:439 [inline]
 kcov_put kernel/kcov.c:435 [inline]
 kcov_close+0x34/0x60 kernel/kcov.c:535
 __fput+0x402/0xb70 fs/file_table.c:468
 task_work_run+0x150/0x240 kernel/task_work.c:227
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x86f/0x2bf0 kernel/exit.c:966
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1107
 get_signal+0x2671/0x26d0 kernel/signal.c:3034
 arch_do_signal_or_restart+0x8f/0x7c0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x85/0x130 kernel/entry/common.c:40
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
 do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f35e95c1785
RSP: 002b:00007f35ea3d2f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f35e97e5fa0 RCX: 00007f35e95c1785
RDX: 00007f35ea3d2fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f35e9611f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 00007f35e97e6038 R14: 00007f35e97e5fa0 R15: 00007fffb211e568
 </TASK>
task:syz-executor    state:R  running task     stack:24152 pid:29561 tgid:29561 ppid:29553  task_flags:0x400140 flags:0x00080001
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5872
Code: 57 0b 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 a2 14 ea 0e 0f 82 74 02 00 00 8b 35 1a 45 ea 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 b9 56 0b 12 0f 85 c7 02 00 00 48 83 c4
RSP: 0018:ffffc9000e7d76b0 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c4460 RCX: 000000000d55228a
RDX: 0000000000000000 RSI: ffffffff8dadd953 RDI: ffffffff8bf1e3c0
RBP: 0000000000000002 R08: 8ea7e1d7bafd6520 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 page_ext_get+0x36/0x1a0 mm/page_ext.c:527
 __reset_page_owner+0x2b/0x1a0 mm/page_owner.c:294
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 discard_slab mm/slub.c:3310 [inline]
 __put_partials+0x130/0x170 mm/slub.c:3857
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4955 [inline]
 slab_alloc_node mm/slub.c:5265 [inline]
 kmem_cache_alloc_noprof+0x250/0x6e0 mm/slub.c:5272
 anon_vma_chain_alloc mm/rmap.c:141 [inline]
 anon_vma_fork+0x200/0x620 mm/rmap.c:363
 dup_mmap+0x151f/0x2280 mm/mmap.c:1797
 dup_mm kernel/fork.c:1489 [inline]
 copy_mm kernel/fork.c:1541 [inline]
 copy_process+0x3f0c/0x76a0 kernel/fork.c:2181
 kernel_clone+0xfc/0x930 kernel/fork.c:2609
 __do_sys_clone+0xce/0x120 kernel/fork.c:2750
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9119785613
RSP: 002b:00007ffdc5cfb788 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9119785613
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 00005555671e57d0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000021 R14: 000000000019b6f0 R15: 00007ffdc5cfb920
 </TASK>
task:syz-executor    state:R  running task     stack:22656 pid:26772 tgid:26772 ppid:26765  task_flags:0x400140 flags:0x00080001
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:unwind_next_frame+0xcda/0x20a0 arch/x86/kernel/unwind_orc.c:583
Code: 6e 0c 00 0f 84 c9 f6 ff ff 80 3d 20 60 3e 12 00 0f 85 bc f6 ff ff 4c 89 ef c6 05 10 60 3e 12 01 e8 2b ee ff ff e9 a8 f6 ff ff <49> 8d 76 f8 ba 08 00 00 00 4d 8d 7d 34 4c 89 ef 4c 89 44 24 28 48
RSP: 0018:ffffc9000b8bf290 EFLAGS: 00000246
RAX: 0000000000000002 RBX: 0000000000000001 RCX: ffffffff9124d5de
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffc9000b8bf348 R08: ffffffff9124d5e2 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000011750 R12: ffffc9000b8bf350
R13: ffffc9000b8bf300 R14: ffffc9000b8bf5f0 R15: ffffc9000b8bf578
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 discard_slab mm/slub.c:3310 [inline]
 __put_partials+0x130/0x170 mm/slub.c:3857
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:408
 kasan_kmalloc include/linux/kasan.h:262 [inline]
 __do_kmalloc_node mm/slub.c:5627 [inline]
 __kmalloc_noprof+0x32f/0x880 mm/slub.c:5639
 kmalloc_noprof include/linux/slab.h:961 [inline]
 tomoyo_realpath_from_path+0xc2/0x6e0 security/tomoyo/realpath.c:251
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_check_open_permission+0x2ab/0x3c0 security/tomoyo/file.c:771
 tomoyo_file_open+0x6b/0x90 security/tomoyo/tomoyo.c:334
 security_file_open+0x84/0x1e0 security/security.c:3183
 do_dentry_open+0x596/0x1530 fs/open.c:942
 vfs_open+0x82/0x3f0 fs/open.c:1097
 do_open fs/namei.c:3975 [inline]
 path_openat+0x1de4/0x2cb0 fs/namei.c:4134
 do_filp_open+0x20b/0x470 fs/namei.c:4161
 do_sys_openat2+0x11b/0x1d0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0x174/0x210 fs/open.c:1463
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5d79b8e7c1
RSP: 002b:00007fff695f7bd0 EFLAGS: 00000287 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f5d79c11d7d RCX: 00007f5d79b8e7c1
RDX: 0000000000090800 RSI: 00007fff695f8d80 RDI: 00000000ffffff9c
RBP: 00007fff695f8d6c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000287 R12: 00007fff695f8d80
R13: 00007f5d79c11d7d R14: 00000000001a006d R15: 00007fff695f8dc0
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 238 jiffies! g156305 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=158860
rcu: rcu_preempt kthread starved for 244 jiffies! g156305 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:I stack:28232 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7026
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: f7 74 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 43 05 24 00 fb f4 <e9> 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6
RAX: 000000000ad1286d RBX: 0000000000000000 RCX: ffffffff8b6622a9
RDX: 0000000000000000 RSI: ffffffff8db0330f RDI: ffffffff8bf1e3c0
RBP: fffffbfff1c12f40 R08: 0000000000000001 R09: ffffed1017086655
R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff8e097a00 R14: ffffffff90832dd0 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8881249d9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557a0335c8 CR3: 0000000075171000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x38d/0x500 kernel/sched/idle.c:330
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
 rest_init+0x16b/0x2b0 init/main.c:757
 start_kernel+0x3f6/0x4e0 init/main.c:1111
 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
 common_startup_64+0x13e/0x148
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/16 18:30 upstream 7ea30958b305 19568248 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in wait4
* Struck through repros no longer work on HEAD.