rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=b0cc/1/0x4000000000000000 softirq=75327/75328 fqs=0 rcu: hardirqs softirqs csw/system rcu: number: 13 21 19 rcu: cputime: 0 79 0 ==> 105150(ms) rcu: (detected by 0, t=10505 jiffies, g=69857, q=1495 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 15085 Comm: rm Not tainted 6.15.0-syzkaller-11796-g5abc7438f1e9 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:130 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x79/0x2c0 mm/kasan/generic.c:189 Code: 00 49 89 ff 49 c1 ef 03 49 ba 00 00 00 00 00 fc ff df 4f 8d 1c 17 49 ff c8 4d 89 c1 49 c1 e9 03 48 bb 01 00 00 00 00 fc ff df <4d> 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 41 RSP: 0018:ffffc90000a08cd0 EFLAGS: 00000807 RAX: ffffffff81ae9001 RBX: dffffc0000000001 RCX: ffffffff81ae9047 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8f9fcbf0 RBP: 0000000000000000 R08: ffffffff8f9fcbf7 R09: 1ffffffff1f3f97e R10: dffffc0000000000 R11: fffffbfff1f3f97e R12: dffffc0000000000 R13: 0000000000000001 R14: ffff8880b8727bc0 R15: 1ffffffff1f3f97e FS: 0000000000000000(0000) GS:ffff888125d90000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8c66b799a0 CR3: 000000002f476000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:638 [inline] cpu_online include/linux/cpumask.h:1197 [inline] trace_hrtimer_start include/trace/events/timer.h:222 [inline] debug_activate kernel/time/hrtimer.c:485 [inline] enqueue_hrtimer+0x77/0x3a0 kernel/time/hrtimer.c:1088 __run_hrtimer kernel/time/hrtimer.c:1778 [inline] __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:in_gate_area_no_mm+0x20/0x60 arch/x86/entry/vsyscall/vsyscall_64.c:321 Code: 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 53 48 89 fb e8 72 c6 8c 00 8b 2d fc 9a 84 0c bf 02 00 00 00 89 ee e8 a0 ca 8c 00 <83> fd 02 40 0f 95 c5 48 81 e3 00 f0 ff ff 48 c7 c7 00 00 60 ff 48 RSP: 0018:ffffc900037374c0 EFLAGS: 00000293 RAX: ffffffff81338510 RBX: 00007ff6d4d4c6c5 RCX: 0000000000000000 RDX: ffff888068f29e00 RSI: 0000000000000001 RDI: 0000000000000002 RBP: 0000000000000001 R08: 0000000000000022 R09: ffffffff81728e15 R10: ffffc90003737578 R11: ffffffff81ace620 R12: ffff888068f29e00 R13: 1ffff920006e6f24 R14: dffffc0000000000 R15: 1ffff920006e6eae is_kernel_text include/linux/kallsyms.h:31 [inline] core_kernel_text kernel/extable.c:68 [inline] kernel_text_address+0x2d/0xe0 kernel/extable.c:99 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xfc/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 __call_rcu_common kernel/rcu/tree.c:3090 [inline] call_rcu+0x142/0x990 kernel/rcu/tree.c:3210 slab_free_hook mm/slub.c:2344 [inline] slab_free mm/slub.c:4642 [inline] kmem_cache_free+0x309/0x400 mm/slub.c:4744 exit_mmap+0x53f/0xb50 mm/mmap.c:1309 __mmput+0x118/0x420 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x640/0x22e0 kernel/exit.c:943 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 __do_sys_exit_group kernel/exit.c:1115 [inline] __se_sys_exit_group kernel/exit.c:1113 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1113 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff6d4d4c6c5 Code: Unable to access opcode bytes at 0x7ff6d4d4c69b. RSP: 002b:00007ffe6fb92c68 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007ff6d4e4dfe8 RCX: 00007ff6d4d4c6c5 RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000 RBP: 0000000000000001 R08: 00007ffe6fb92bf8 R09: 0000000000000000 R10: 00007ffe6fb92a90 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff6d4e4c680 R15: 00007ff6d4e4e000 rcu: rcu_preempt kthread starved for 10505 jiffies! g69857 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:27192 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 14973 Comm: udevd Not tainted 6.15.0-syzkaller-11796-g5abc7438f1e9 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885 Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 50 78 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 fb 73 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 e0 73 0b RSP: 0018:ffffc900043ff5a0 EFLAGS: 00000293 RAX: ffffffff81b4d790 RBX: ffff8880b863c9c0 RCX: ffff888030fa8000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900043ff700 R08: ffffffff8f9fcbf7 R09: 1ffffffff1f3f97e R10: dffffc0000000000 R11: fffffbfff1f3f97f R12: 1ffff110170e825d R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b87412e8 FS: 0000000000000000(0000) GS:ffff888125c90000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055ade9623a08 CR3: 000000000df38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411 arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline] exit_mmap+0x17c/0xb50 mm/mmap.c:1270 __mmput+0x118/0x420 kernel/fork.c:1121 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x640/0x22e0 kernel/exit.c:943 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 __do_sys_exit_group kernel/exit.c:1115 [inline] __se_sys_exit_group kernel/exit.c:1113 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1113 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f59bf0f16c5 Code: Unable to access opcode bytes at 0x7f59bf0f169b. RSP: 002b:00007ffe45ffa3e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000055ade9648380 RCX: 00007f59bf0f16c5 RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000 RBP: 000055ade961a910 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe45ffa430 R14: 0000000000000000 R15: 0000000000000000