rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=6314/1/0x4000000000000000 softirq=9334/9335 fqs=5 rcu: (detected by 0, t=10502 jiffies, g=11961, q=881 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5484 Comm: dhcpcd-run-hook Not tainted 6.8.0-rc2-syzkaller-g41bccc98fb79 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:200 Code: c6 5d e2 02 66 0f 1f 44 00 00 f3 0f 1e fa 48 8b be b0 01 00 00 e8 b0 ff ff ff 31 c0 c3 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 0f 1e fa 65 48 8b 14 25 40 c2 03 00 65 8b 05 e4 b2 7c 7e a9 00 RSP: 0018:ffffc900001f0e10 EFLAGS: 00000002 RAX: 0000000080010001 RBX: ffff8880b992bbc0 RCX: ffffffff8175a9a3 RDX: ffff88801af85940 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff8880201ad340 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffffffff8acf2120 R12: 0000000000000001 R13: 0000000000000000 R14: ffff8880201ad340 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9ccb8d9ba8 CR3: 000000006a34c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hrtimer_start include/trace/events/timer.h:222 [inline] debug_activate kernel/time/hrtimer.c:478 [inline] enqueue_hrtimer+0x280/0x310 kernel/time/hrtimer.c:1087 __run_hrtimer kernel/time/hrtimer.c:1705 [inline] __hrtimer_run_queues+0xa12/0xc20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x105/0x400 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:arch_stack_walk+0xde/0x170 arch/x86/kernel/stacktrace.c:27 Code: 54 00 4c 89 e7 e8 02 2f 08 00 31 ff 48 89 c3 48 89 c6 e8 55 fb 54 00 48 85 db 74 3d e8 bb ff 54 00 48 89 de 4c 89 f7 41 ff d5 <31> ff 89 c3 89 c6 e8 d7 fa 54 00 84 db 74 20 e8 9e ff 54 00 4c 89 RSP: 0018:ffffc90003427680 EFLAGS: 00000282 RAX: 0000000000000001 RBX: ffffffff842d27bf RCX: ffffffff81320f8b RDX: 1ffff92000684efd RSI: ffffffff842d27bf RDI: ffffc90003427754 RBP: ffffc90003427718 R08: 0000000000000007 R09: 0000000000000000 R10: ffffffff842d27bf R11: 0000000000000001 R12: ffffc90003427688 R13: ffffffff81745ae0 R14: ffffc90003427748 R15: ffff88801af85940 stack_trace_save+0x96/0xd0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x50 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3f/0x60 mm/kasan/generic.c:640 poison_slab_object mm/kasan/common.c:241 [inline] __kasan_slab_free+0x121/0x1b0 mm/kasan/common.c:257 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2121 [inline] slab_free mm/slub.c:4299 [inline] kfree+0x124/0x360 mm/slub.c:4409 tomoyo_realpath_from_path+0x1a6/0x710 security/tomoyo/realpath.c:286 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x26f/0x450 security/tomoyo/file.c:822 security_inode_getattr+0xf1/0x150 security/security.c:2237 vfs_getattr fs/stat.c:173 [inline] vfs_fstat+0x4f/0xc0 fs/stat.c:198 vfs_fstatat+0x130/0x140 fs/stat.c:300 __do_sys_newfstatat+0x98/0x110 fs/stat.c:468 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f9ccbb808a9 Code: 49 01 00 09 00 00 00 83 c8 ff c3 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 00 00 00 00 41 89 ca b8 06 01 00 00 0f 05 <45> 31 c0 3d 00 f0 ff ff 76 0c f7 d8 41 83 c8 ff 89 05 a1 49 01 00 RSP: 002b:00007ffdaaf03a38 EFLAGS: 00000206 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9ccbb808a9 RDX: 00007ffdaaf03ae0 RSI: 00007f9ccbb8b3d4 RDI: 0000000000000003 RBP: 00007ffdaaf03ba0 R08: 00007f9ccbb64550 R09: 00007f9ccbb63fc0 R10: 0000000000001000 R11: 0000000000000206 R12: 00007f9ccbb63fc0 R13: 00007ffdaaf03c28 R14: 00007f9ccbb63fc0 R15: 0000000000000001 rcu: rcu_preempt kthread starved for 10492 jiffies! g11961 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:26368 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0xf12/0x5c00 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0xe9/0x270 kernel/sched/core.c:6817 schedule_timeout+0x137/0x290 kernel/time/timer.c:2183 rcu_gp_fqs_loop+0x1ec/0xb10 kernel/rcu/tree.c:1663 rcu_gp_kthread+0x24b/0x380 kernel/rcu/tree.c:1862 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 12 Comm: kworker/u4:1 Not tainted 6.8.0-rc2-syzkaller-g41bccc98fb79 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x4e4/0x1550 kernel/smp.c:855 Code: 0b 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 2e c5 0b 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 24 0e 00 00 8b 43 08 31 RSP: 0018:ffffc90000117930 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9941fe0 RCX: ffffffff817b4a48 RDX: ffff888015695940 RSI: ffffffff817b4a22 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed10173283fd R13: 0000000000000001 R14: ffff8880b9941fe8 R15: ffff8880b983de40 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000600 CR3: 000000000cf78000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2087 [inline] text_poke_bp_batch+0x22b/0x750 arch/x86/kernel/alternative.c:2297 text_poke_flush arch/x86/kernel/alternative.c:2488 [inline] text_poke_flush arch/x86/kernel/alternative.c:2485 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2495 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:826 [inline] toggle_allocation_gate+0xf4/0x250 mm/kfence/core.c:818 process_one_work+0x886/0x15d0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242