rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...0: (1 GPs behind) idle=791/1/0x4000000000000000 softirq=6104/6136 fqs=2100 (detected by 0, t=10504 jiffies, g=6053, q=696) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3648 Comm: udevd Not tainted 5.15.166-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:__preempt_count_add kernel/rcu/tree.c:1119 [inline] RIP: 0010:rcu_is_watching+0x4/0xa0 kernel/rcu/tree.c:1122 Code: 5d 41 5e 41 5f 5d c3 e8 ba 04 c9 08 41 f7 c4 00 02 00 00 75 b4 eb b3 e8 9a 04 c9 08 66 2e 0f 1f 84 00 00 00 00 00 41 57 41 56 <53> 65 ff 05 ec 56 97 7e e8 3f 18 c9 08 89 c3 83 f8 08 73 72 49 bf RSP: 0018:ffffc90000dd0d48 EFLAGS: 00000002 RAX: 0000000000010000 RBX: 0000000000000001 RCX: ffffffff816f686e RDX: ffff888076745940 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000dd0eb0 R08: ffffffff816f6896 R09: fffffbfff1bd2b66 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880b912a200 R13: ffffffff88817b70 R14: ffff88807c16bb40 R15: dffffc0000000001 FS: 00007fb98c2a5c80(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffeda34cfa8 CR3: 00000000230ba000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hrtimer_expire_entry include/trace/events/timer.h:236 [inline] __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x500/0xcf0 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline] __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:aa_file_perm+0xbb/0xf60 security/apparmor/file.c:607 Code: 66 41 c7 44 1c 19 f3 f3 41 c6 44 1c 1b f3 e8 8c 4a b3 fd 4d 85 f6 0f 84 d1 0b 00 00 e8 7e 4a b3 fd 4d 85 ff 0f 84 e6 0b 00 00 70 4a b3 fd 4c 89 74 24 08 4d 8d b7 a8 01 00 00 4c 89 f0 48 c1 RSP: 0018:ffffc90002cf7a80 EFLAGS: 00000286 RAX: ffffffff83cd0f82 RBX: dffffc0000000000 RCX: ffff888076745940 RDX: 0000000000000000 RSI: ffff8880171d52b0 RDI: ffffffff8ad35ec0 RBP: ffffc90002cf7c18 R08: 0000000000000000 R09: ffffed10044dc010 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200059ef5c R13: ffff8880226e0000 R14: ffff8880171d52b0 R15: ffff8880226e0000 common_file_perm+0x173/0x1d0 security/apparmor/lsm.c:475 security_file_permission+0x65/0xa0 security/security.c:1521 rw_verify_area fs/read_write.c:389 [inline] vfs_read+0x253/0xe10 fs/read_write.c:476 ksys_read+0x1a2/0x2c0 fs/read_write.c:623 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fb98c3d0b6a Code: 00 3d 00 00 41 00 75 0d 50 48 8d 3d 2d 08 0a 00 e8 ea 7d 01 00 31 c0 e9 07 ff ff ff 64 8b 04 25 18 00 00 00 85 c0 75 1b 0f 05 <48> 3d 00 f0 ff ff 76 6c 48 8b 15 8f a2 0d 00 f7 d8 64 89 02 48 83 RSP: 002b:00007ffeda350f08 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000055c1bbdf3870 RCX: 00007fb98c3d0b6a RDX: 0000000000001000 RSI: 000055c1bbde9950 RDI: 0000000000000008 RBP: 000055c1bbdf3870 R08: 0000000000000008 R09: 0000000000000000 R10: 0000000000000007 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000003fff R14: 00007ffeda3513e8 R15: 000000000000000a INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.373 msecs