rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3092/1:b..l (detected by 0, t=10502 jiffies, g=31653, q=261 ncpus=2) task:udevd state:R running task stack:22600 pid:3092 ppid:1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:preempt_count_add+0x4/0x180 kernel/sched/core.c:5697 Code: 80 e1 07 80 c1 03 38 c1 7c 97 48 8b 3c 24 e8 93 bb 83 00 eb 8c e9 f2 fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 41 57 41 56 <53> 89 fb 48 c7 c0 60 41 33 97 48 c1 e8 03 49 bf 00 00 00 00 00 fc RSP: 0018:ffffc9000317f628 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc9000317f720 RCX: ffffc9000317fa40 RDX: dffffc0000000000 RSI: ffffffff81d5e923 RDI: 0000000000000001 RBP: 1ffff9200062fee4 R08: 0000000000000000 R09: ffffc9000317f810 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807e55bb80 R13: ffffffff81786c50 R14: dffffc0000000000 R15: ffffffff81d5e923 unwind_next_frame+0xb3/0x2220 arch/x86/kernel/unwind_orc.c:433 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 save_stack+0xf6/0x1e0 mm/page_owner.c:127 __reset_page_owner+0x52/0x1a0 mm/page_owner.c:148 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1444 [inline] free_pcp_prepare mm/page_alloc.c:1494 [inline] free_unref_page_prepare+0xf63/0x1120 mm/page_alloc.c:3369 free_unref_page+0x33/0x3e0 mm/page_alloc.c:3464 free_slab mm/slub.c:2031 [inline] discard_slab mm/slub.c:2037 [inline] __unfreeze_partials+0x1b7/0x210 mm/slub.c:2586 put_cpu_partial+0x17b/0x250 mm/slub.c:2662 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x156/0x170 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1f/0x70 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737 slab_alloc_node mm/slub.c:3398 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x10c/0x2d0 mm/slub.c:3422 getname_flags+0xb8/0x4f0 fs/namei.c:139 vfs_fstatat fs/stat.c:266 [inline] __do_sys_newfstatat fs/stat.c:437 [inline] __se_sys_newfstatat fs/stat.c:431 [inline] __x64_sys_newfstatat+0x130/0x1e0 fs/stat.c:431 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fad97b165f4 RSP: 002b:00007ffc8a266438 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 0000562b74cfa6c0 RCX: 00007fad97b165f4 RDX: 00007ffc8a266448 RSI: 0000562b74ce87ed RDI: 00000000ffffff9c RBP: 0000562b9b1a6c28 R08: 0000000018befbd9 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 0000000000000001 R15: 0000562b74ceedca rcu: rcu_preempt kthread timer wakeup didn't happen for 7946 jiffies! g31653 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=19697 rcu: rcu_preempt kthread starved for 7947 jiffies! g31653 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26752 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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: 7267 Comm: syz.2.963 Not tainted 6.1.112-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__lock_acquire+0x12af/0x1f80 kernel/locking/lockdep.c:5059 Code: 77 00 48 ba 00 00 00 00 00 fc ff df 48 89 2b 48 8b 44 24 28 0f b6 04 10 84 c0 0f 85 61 08 00 00 41 8b 04 24 ff c0 41 89 04 24 <83> f8 30 0f 83 c4 02 00 00 be 01 00 00 00 3b 05 ad 3a b3 0f 0f 86 RSP: 0018:ffffc9000b187700 EFLAGS: 00000002 RAX: 0000000000000001 RBX: ffff88807b8c2890 RCX: ffffffff816b3d32 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff911dd250 RBP: c43e8954cd7f2d9e R08: dffffc0000000000 R09: fffffbfff223ba4b R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88807b8c2898 R13: ffff88807b8c1dc0 R14: 0000000000000001 R15: 1ffff1100f718518 FS: 00007f5b91fde6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8749b08ef8 CR3: 0000000074e0d000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __might_fault+0xbd/0x110 mm/memory.c:5851 __copy_to_user include/linux/uaccess.h:111 [inline] save_xstate_epilog arch/x86/kernel/fpu/signal.c:127 [inline] copy_fpstate_to_sigframe+0xb16/0xda0 arch/x86/kernel/fpu/signal.c:245 get_sigframe+0x378/0x4b0 arch/x86/kernel/signal.c:297 __setup_rt_frame arch/x86/kernel/signal.c:472 [inline] setup_rt_frame arch/x86/kernel/signal.c:784 [inline] handle_signal arch/x86/kernel/signal.c:828 [inline] arch_do_signal_or_restart+0x4ef/0x1a10 arch/x86/kernel/signal.c:873 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f5b9117dff9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5b91fde0e8 EFLAGS: 00000246 RAX: fffffffffffffffc RBX: 00007f5b91335f88 RCX: 00007f5b9117dff9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f5b91335f88 RBP: 00007f5b91335f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5b91335f8c R13: 0000000000000000 R14: 00007fff0c5b3a00 R15: 00007fff0c5b3ae8