rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5182/1:b..l P11540/1:b..l rcu: (detected by 1, t=10502 jiffies, g=50877, q=743 ncpus=2) task:sed state:R running task stack:27416 pid:11540 tgid:11540 ppid:11536 task_flags:0x400000 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256 irqentry_exit+0x36/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:unwind_next_frame+0x1564/0x20a0 arch/x86/kernel/unwind_orc.c:648 Code: 84 fa ff ff 4c 89 e7 e8 fa 82 b9 00 e9 77 fa ff ff 48 ba 00 00 00 00 00 fc ff df 48 8d 79 02 48 89 f8 48 c1 e8 03 0f b6 34 10 <48> 8d 41 03 49 89 c0 49 c1 e8 03 41 0f b6 14 10 49 89 f8 41 83 e0 RSP: 0018:ffffc9000fb4f0c8 EFLAGS: 00000a07 RAX: 1ffffffff22463b8 RBX: 0000000000000001 RCX: ffffffff91231dc2 RDX: dffffc0000000000 RSI: 0000000000000000 RDI: ffffffff91231dc4 RBP: ffffc9000fb4f180 R08: ffffffff91231dc6 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000011500 R12: ffffc9000fb4f188 R13: ffffc9000fb4f138 R14: ffffc9000fb4f6a0 R15: ffffc9000fb4f16c arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4978 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_noprof+0x250/0x6e0 mm/slub.c:5295 vm_area_dup+0x27/0x8d0 mm/vma_init.c:123 __split_vma+0x18e/0x1070 mm/vma.c:515 vms_gather_munmap_vmas+0x1cb/0x1340 mm/vma.c:1359 do_vmi_align_munmap+0x286/0x7e0 mm/vma.c:1527 do_vmi_munmap+0x204/0x3e0 mm/vma.c:1584 __vm_munmap+0x196/0x380 mm/vma.c:3156 elf_map fs/binfmt_elf.c:397 [inline] elf_load+0x349/0x780 fs/binfmt_elf.c:422 load_elf_interp fs/binfmt_elf.c:689 [inline] load_elf_binary+0x37a6/0x4fe0 fs/binfmt_elf.c:1254 search_binary_handler fs/exec.c:1670 [inline] exec_binprm fs/exec.c:1702 [inline] bprm_execve fs/exec.c:1754 [inline] bprm_execve+0x8be/0x1640 fs/exec.c:1730 do_execveat_common.isra.0+0x4a5/0x610 fs/exec.c:1860 do_execve fs/exec.c:1934 [inline] __do_sys_execve fs/exec.c:2010 [inline] __se_sys_execve fs/exec.c:2005 [inline] __x64_sys_execve+0x8e/0xb0 fs/exec.c:2005 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f37ddd89107 RSP: 002b:00007ffe0adad658 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 000055bea1924f48 RCX: 00007f37ddd89107 RDX: 000055bea1924f70 RSI: 000055bea1924f48 RDI: 000055bea1925028 RBP: 000055bea1925028 R08: 00007ffe0adb3ddd R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 000055bea1924f70 R13: 00007f37ddf4ee8b R14: 000055bea1924f70 R15: 0000000000000000 task:udevd state:R running task stack:24728 pid:5182 tgid:5182 ppid:1 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7113 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194 sock_def_readable+0x15b/0x600 net/core/sock.c:3551 __netlink_sendskb net/netlink/af_netlink.c:1265 [inline] netlink_sendskb net/netlink/af_netlink.c:1271 [inline] netlink_unicast+0x75f/0x870 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684 __sys_sendmsg+0x16d/0x220 net/socket.c:2716 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb11eea7407 RSP: 002b:00007ffd7be10d10 EFLAGS: 00000202 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fb11f624880 RCX: 00007fb11eea7407 RDX: 0000000000000000 RSI: 00007ffd7be10d70 RDI: 0000000000000004 RBP: 000055e38ff531f0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000088 R13: 000055e38fc7ad80 R14: 0000000000000000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10484 jiffies! g50877 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:28336 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: a7 6c 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 83 55 29 00 fb f4 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c6 RAX: 000000000121a283 RBX: 0000000000000000 RCX: ffffffff8b60d2a9 RDX: 0000000000000000 RSI: ffffffff8da2c59c RDI: ffffffff8bf073c0 RBP: fffffbfff1c12f40 R08: 0000000000000001 R09: ffffed1017086655 R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e097a00 R14: ffffffff908216d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124a05000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c36736d CR3: 00000000227a8000 CR4: 00000000003526f0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3f6/0x4e0 init/main.c:1111 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148