rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5802/1:b..l P5791/1:b..l rcu: (detected by 0, t=10502 jiffies, g=29129, q=462 ncpus=2) task:udevd state:R running task stack:23688 pid:5791 ppid:5157 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline] RIP: 0010:write_comp_data kernel/kcov.c:244 [inline] RIP: 0010:__sanitizer_cov_trace_cmp8+0x8/0x80 kernel/kcov.c:293 Code: 08 04 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d e0 22 7e 7e 65 8b 15 e1 22 7e 7e 81 e2 00 01 ff 00 74 RSP: 0018:ffffc900045ef480 EFLAGS: 00000246 RAX: ffffffff8192bff0 RBX: 0000000000000000 RCX: ffff88802af23c00 RDX: 0000000000000000 RSI: 00007f297431e097 RDI: ffffffffa0004740 RBP: 0000000000000000 R08: dffffc0000000000 R09: 1ffffffff21b52a0 R10: dffffc0000000000 R11: fffffbfff21b52a1 R12: ffffffffa0004740 R13: dffffc0000000000 R14: 00007f297431e097 R15: ffffffff8dfbf9f8 bpf_tree_comp kernel/bpf/core.c:632 [inline] __lt_find include/linux/rbtree_latch.h:115 [inline] latch_tree_find include/linux/rbtree_latch.h:208 [inline] bpf_ksym_find kernel/bpf/core.c:708 [inline] is_bpf_text_address+0x140/0x2a0 kernel/bpf/core.c:742 kernel_text_address+0xa0/0xd0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:52 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3519 vma_lock_alloc kernel/fork.c:460 [inline] vm_area_dup+0x61/0x270 kernel/fork.c:513 __split_vma+0x19f/0xc00 mm/mmap.c:2373 do_vmi_align_munmap+0x2dc/0x1660 mm/mmap.c:2501 do_vmi_munmap+0x252/0x2d0 mm/mmap.c:2660 __vm_munmap+0x193/0x3c0 mm/mmap.c:2961 __do_sys_munmap mm/mmap.c:2978 [inline] __se_sys_munmap mm/mmap.c:2975 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:2975 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f297431e097 RSP: 002b:00007ffe5375d858 EFLAGS: 00000246 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 00005641262519a0 RCX: 00007f297431e097 RDX: 0000564126255408 RSI: 0000000000000200 RDI: 00007f2974a2e000 RBP: 0000000000000003 R08: 0000000000000030 R09: 0000564126255280 R10: 0000000000000010 R11: 0000000000000246 R12: 00005641262540b0 R13: 00007f2974b5839c R14: 0000000000000600 R15: 0000000000000009 task:udevd state:R running task stack:24168 pid:5802 ppid:5157 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x82/0x90 kernel/kcov.c:315 Code: 8d 52 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 05 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 RSP: 0018:ffffc900046ef5e0 EFLAGS: 00000293 RAX: ffffffff8a620c0d RBX: dffffc0000000000 RCX: 0000000000000000 RDX: ffff88807bfbbc00 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffea000156a340 R08: ffff88807bfbbc00 R09: 0000000000000002 R10: 0000000000000003 R11: 0000000000000000 R12: 1ffff920008ddede R13: ffffc900046ef6f2 R14: 0000000000000001 R15: ffffc900046ef6f8 xa_entry include/linux/xarray.h:1216 [inline] xas_find+0x5bd/0xab0 lib/xarray.c:1267 find_get_entry mm/filemap.c:2013 [inline] find_lock_entries+0x1c7/0xfe0 mm/filemap.c:2114 shmem_undo_range+0x254/0x1a40 mm/shmem.c:1008 shmem_truncate_range mm/shmem.c:1135 [inline] shmem_evict_inode+0x273/0xa70 mm/shmem.c:1264 evict+0x486/0x870 fs/inode.c:705 __dentry_kill+0x431/0x650 fs/dcache.c:611 dentry_kill+0xb8/0x290 fs/dcache.c:-1 dput+0xfe/0x1e0 fs/dcache.c:918 __fput+0x5e5/0x970 fs/file_table.c:392 task_work_run+0x1ce/0x250 kernel/task_work.c:239 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f29742a7407 RSP: 002b:00007ffe53762b80 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007f2974a31880 RCX: 00007f29742a7407 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008 RBP: 00007f2974a316e8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 R13: 000056412625e410 R14: 0000000000000008 R15: 000056412626a990 rcu: rcu_preempt kthread starved for 9964 jiffies! g29129 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:27752 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:148 Code: cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d a3 14 39 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 66 0f 1f 00 55 41 57 41 56 RSP: 0018:ffffffff8ca07d80 EFLAGS: 000002c6 RAX: 786a900b1141fe00 RBX: ffffffff8161881b RCX: 786a900b1141fe00 RDX: 0000000000000001 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80 RBP: ffffffff8ca07eb8 R08: ffff8880b8e36b2b R09: 1ffff110171c6d65 R10: dffffc0000000000 R11: ffffed10171c6d66 R12: ffffffff8e4a93e8 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1952688 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efde815bd58 CR3: 0000000019ec2000 CR4: 00000000003506f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:753 default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97 cpuidle_idle_call kernel/sched/idle.c:170 [inline] do_idle+0x1eb/0x510 kernel/sched/idle.c:282 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:380 rest_init+0x2e2/0x300 init/main.c:744 arch_call_rest_init+0xe/0x10 init/main.c:841 start_kernel+0x459/0x4e0 init/main.c:1086 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555 x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536 secondary_startup_64_no_verify+0x179/0x17b