rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2972/1:b..l (detected by 0, t=10506 jiffies, g=79525, q=92 ncpus=2) task:udevd state:R running task stack:24816 pid:2972 ppid:1 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5191 [inline] __schedule+0xae9/0x53f0 kernel/sched/core.c:6503 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6815 irqentry_exit+0x31/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:__kuid_val include/linux/uidgid.h:36 [inline] RIP: 0010:uid_eq include/linux/uidgid.h:63 [inline] RIP: 0010:acl_permission_check fs/namei.c:343 [inline] RIP: 0010:generic_permission+0x184/0x7a0 fs/namei.c:404 Code: 80 3c 11 00 0f 85 c0 05 00 00 4d 8b b6 10 08 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d 7e 2c 48 89 f9 48 c1 e9 03 0f b6 0c 01 <48> 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85 49 03 00 00 45 RSP: 0018:ffffc900031dfa78 EFLAGS: 00000217 RAX: dffffc0000000000 RBX: 00000000000041ed RCX: 0000000000000000 RDX: dffffc0000000000 RSI: ffffffff81da2bf9 RDI: ffff88801837c02c RBP: ffff888144c782b0 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000081 R13: ffffffff8be44360 R14: ffff88801837c000 R15: 0000000000000000 do_inode_permission fs/namei.c:465 [inline] inode_permission.part.0+0x99/0x670 fs/namei.c:525 inode_permission fs/namei.c:506 [inline] may_lookup fs/namei.c:1711 [inline] link_path_walk.part.0+0x277/0xe20 fs/namei.c:2262 link_path_walk fs/namei.c:2244 [inline] path_lookupat+0xb7/0x840 fs/namei.c:2473 filename_lookup+0x1ce/0x590 fs/namei.c:2503 user_path_at_empty+0x42/0x60 fs/namei.c:2876 do_readlinkat+0xcd/0x2f0 fs/stat.c:468 __do_sys_readlink fs/stat.c:501 [inline] __se_sys_readlink fs/stat.c:498 [inline] __x64_sys_readlink+0x74/0xb0 fs/stat.c:498 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f015b327277 RSP: 002b:00007fffa85b64c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000059 RAX: ffffffffffffffda RBX: 00007fffa85b64d8 RCX: 00007f015b327277 RDX: 0000000000000400 RSI: 00007fffa85b64d8 RDI: 00007fffa85b69b8 RBP: 0000000000000400 R08: 000000001fffffff R09: 00007f015b3f5a60 R10: 000055bc1e8fd8d0 R11: 0000000000000246 R12: 00007fffa85b69b8 R13: 00007fffa85b6928 R14: 000055bc1e8d2910 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10502 jiffies! g79525 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:R running task stack:28184 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5191 [inline] __schedule+0xae9/0x53f0 kernel/sched/core.c:6503 schedule+0xda/0x1b0 kernel/sched/core.c:6579 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1660 rcu_gp_kthread+0x236/0x360 kernel/rcu/tree.c:1859 kthread+0x2e4/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 13705 Comm: syz-executor.3 Not tainted 6.1.0-rc4-syzkaller-00362-gfef7fd48922d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:mark_lock.part.0+0x171/0x1910 kernel/locking/lockdep.c:4653 Code: 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 c7 43 14 00 00 00 00 48 8b 84 24 30 01 00 00 65 48 2b 04 25 28 00 00 00 <0f> 85 2b 13 00 00 48 81 c4 38 01 00 00 44 89 d0 5b 5d 41 5c 41 5d RSP: 0018:ffffc900001e09d8 EFLAGS: 00000046 RAX: 0000000000000000 RBX: fffff5200003c142 RCX: 1ffffffff2136d9e RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffffffff909b6cf0 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff90932a9f R10: 0000000000000001 R11: 0000000000000000 R12: ffff88801f734548 R13: 0000000000000000 R14: 0000000000000aff R15: ffff88801f734568 FS: 00005555566a8400(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe83c6abf8 CR3: 00000000a0ce1000 CR4: 0000000000350ee0 Call Trace: mark_lock kernel/locking/lockdep.c:4598 [inline] mark_usage kernel/locking/lockdep.c:4526 [inline] __lock_acquire+0x14a2/0x56d0 kernel/locking/lockdep.c:5009 lock_acquire kernel/locking/lockdep.c:5668 [inline] lock_acquire+0x1df/0x630 kernel/locking/lockdep.c:5633 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:350 [inline] advance_sched+0x53/0x9a0 net/sched/sch_taprio.c:700 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x690/0xfb0 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline] __sysvec_apic_timer_interrupt+0x17c/0x640 arch/x86/kernel/apic/apic.c:1113 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xd/0x60 kernel/kcov.c:207 Code: 00 00 e9 96 56 87 02 66 0f 1f 44 00 00 48 8b be a8 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 f9 c2 85 7e 89 c1 48 8b 34 24 <81> e1 00 01 00 00 65 48 8b 14 25 c0 6f 02 00 a9 00 01 ff 00 74 0e RSP: 0018:ffffc90003a8fad8 EFLAGS: 00000216 RAX: 0000000080000000 RBX: ffff8880744d0886 RCX: 0000000080000000 RDX: ffff88801f733a80 RSI: ffffffff83c5ad4c RDI: 0000000000000001 RBP: ffffc90003a8fb60 R08: 0000000000000001 R09: 000000000000005c R10: 0000000000000073 R11: 000000000008c07e R12: 0000000000000006 R13: ffff8880744d0880 R14: 000000000000003f R15: 0000000000000073 tomoyo_const_part_length security/tomoyo/util.c:644 [inline] tomoyo_fill_path_info+0xbc/0x410 security/tomoyo/util.c:682 tomoyo_get_realpath security/tomoyo/file.c:153 [inline] tomoyo_path_perm+0x2b0/0x400 security/tomoyo/file.c:822 tomoyo_path_unlink+0x8e/0xd0 security/tomoyo/tomoyo.c:149 security_path_unlink+0xd7/0x150 security/security.c:1175 do_unlinkat+0x363/0x650 fs/namei.c:4315 __do_sys_unlink fs/namei.c:4367 [inline] __se_sys_unlink fs/namei.c:4365 [inline] __x64_sys_unlink+0xc6/0x110 fs/namei.c:4365 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fc18008af77 Code: 73 01 c3 48 c7 c1 b8 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 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe83c6b338 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc18008af77 RDX: 00007ffe83c6b370 RSI: 00007ffe83c6b370 RDI: 00007ffe83c6b400 RBP: 00007ffe83c6b400 R08: 0000000000000001 R09: 00007ffe83c6b1d0 R10: 00005555566a9893 R11: 0000000000000206 R12: 00007fc1800e5826 R13: 00007ffe83c6c4c0 R14: 00005555566a9810 R15: 00007ffe83c6c500