rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3026/1:b..l (detected by 1, t=10502 jiffies, g=25485, q=246) task:udevd state:R running task stack:22328 pid: 3026 ppid: 1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627 Code: 2b 00 74 08 4c 89 f7 e8 0c 75 67 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90002327760 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000464ef8 RCX: 1ffff92000464e98 RDX: dffffc0000000000 RSI: ffffffff8a8b3da0 RDI: ffffffff8ad904c0 RBP: ffffc900023278c0 R08: dffffc0000000000 R09: fffffbfff20e2419 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000464ef4 R13: dffffc0000000000 R14: ffffc900023277c0 R15: 0000000000000246 rcu_lock_acquire+0x20/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] percpu_ref_put_many include/linux/percpu-refcount.h:317 [inline] percpu_ref_put include/linux/percpu-refcount.h:338 [inline] obj_cgroup_put+0xe/0xc0 include/linux/memcontrol.h:816 memcg_slab_free_hook+0x6b/0x200 mm/slab.h:367 do_slab_free mm/slub.c:3432 [inline] ___cache_free+0x67/0x100 mm/slub.c:3506 qlist_free_all+0x36/0x90 mm/kasan/quarantine.c:176 kasan_quarantine_reduce+0x162/0x180 mm/kasan/quarantine.c:283 __kasan_slab_alloc+0x2f/0xc0 mm/kasan/common.c:444 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 getname_flags+0xb8/0x4e0 fs/namei.c:138 do_sys_openat2+0xd2/0x4f0 fs/open.c:1247 do_sys_open fs/open.c:1269 [inline] __do_sys_openat fs/open.c:1285 [inline] __se_sys_openat fs/open.c:1280 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1280 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: 0033:0x7f3197056477 RSP: 002b:00007ffe2c3b7aa8 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00005651d8e02430 RCX: 00007f3197056477 RDX: 0000000000090800 RSI: 00005651d8de0980 RDI: 00000000ffffff9c RBP: 00005651d8e4eab0 R08: 0000000000090800 R09: 00005651d8de0980 R10: 0000000000000000 R11: 0000000000000287 R12: 00005651d8de0980 R13: 00000000000000ff R14: 00005651bf8a81c4 R15: 0000000000000000 rcu: rcu_preempt kthread timer wakeup didn't happen for 8738 jiffies! g25485 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=20975 rcu: rcu_preempt kthread starved for 8739 jiffies! g25485 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:26168 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6060 Comm: syz.1.524 Not tainted 5.15.167-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:360 [inline] RIP: 0010:unwind_next_frame+0xb4b/0x1fa0 arch/x86/kernel/unwind_orc.c:539 Code: 00 00 00 fc ff df 0f 85 65 0b 00 00 48 89 df e8 9b 1c 00 00 48 b9 00 00 00 00 00 fc ff df 48 89 c3 48 8b 44 24 28 80 3c 08 00 <48> 8b 6c 24 08 74 12 48 89 ef e8 66 91 91 00 48 b9 00 00 00 00 00 RSP: 0018:ffffc9000334f608 EFLAGS: 00000046 RAX: 1ffff92000669eed RBX: ffffffff812fdcfb RCX: dffffc0000000000 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffc9000334f718 RBP: ffffc90003350000 R08: 0000000000000010 R09: ffffc9000334f720 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1cbf6fa R13: 1ffffffff1cbf6fa R14: ffffc90003348000 R15: ffffc9000334f720 FS: 00007f2aa14e36c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2aa3222f88 CR3: 0000000079bcd000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __unwind_start+0x59d/0x720 arch/x86/kernel/unwind_orc.c:704 unwind_start arch/x86/include/asm/unwind.h:60 [inline] arch_stack_walk+0xdb/0x140 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x8e/0xc0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x53/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0xf3/0x280 mm/slub.c:3233 __sigqueue_alloc+0x3be/0x4d0 kernel/signal.c:435 __send_signal+0x21f/0xd40 kernel/signal.c:1116 do_send_sig_info kernel/signal.c:1294 [inline] group_send_sig_info+0x260/0x2d0 kernel/signal.c:1442 bpf_send_signal_common+0x2d8/0x420 kernel/trace/bpf_trace.c:824 ____bpf_send_signal kernel/trace/bpf_trace.c:829 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:827 bpf_prog_7ba5217f62dcd359+0x38/0xa7c bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run2+0x19e/0x340 kernel/trace/bpf_trace.c:1917 __bpf_trace_sys_enter+0x60/0x70 include/trace/events/syscalls.h:18 trace_sys_enter include/trace/events/syscalls.h:18 [inline] syscall_trace_enter kernel/entry/common.c:77 [inline] __syscall_enter_from_user_work kernel/entry/common.c:96 [inline] syscall_enter_from_user_mode+0x202/0x240 kernel/entry/common.c:114 do_syscall_64+0x1e/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f2aa3006959 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007f2aa14e2b40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007f2aa3222f88 RCX: 00007f2aa3006959 RDX: 00007f2aa14e2b40 RSI: 00007f2aa14e2c70 RDI: 0000000000000011 RBP: 00007f2aa3222f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f2aa3222f8c R13: 0000000000000000 R14: 00007fff18342f10 R15: 00007fff18342ff8