rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P25649/1:b..l rcu: (detected by 0, t=10502 jiffies, g=242909, q=652 ncpus=2) task:syz-executor state:R running task stack:23528 pid:25649 tgid:25649 ppid:25636 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7188 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 7b 2f 26 12 83 f8 07 0f 87 d9 02 00 00 48 0f a3 05 86 28 f3 0e 0f 82 a4 02 00 00 8b 35 0e 5c f3 0e 85 f6 0f 85 bf 00 00 00 <48> 8b 44 24 30 65 48 2b 05 1d 2f 26 12 0f 85 ed 02 00 00 48 83 c4 RSP: 0018:ffffc9000543f2a0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8defa95c RDI: ffffffff8c1c3600 RBP: ffffffff8e7e54e0 R08: 00000000b99d6e47 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] free_unref_folios+0xa0d/0x16f0 mm/page_alloc.c:3004 folios_put_refs+0x571/0xa90 mm/swap.c:1008 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x5e5/0x1570 mm/shmem.c:1149 shmem_truncate_range mm/shmem.c:1277 [inline] shmem_evict_inode+0x3f3/0xc40 mm/shmem.c:1407 evict+0x3c2/0xad0 fs/inode.c:841 iput_final fs/inode.c:1960 [inline] iput.part.0+0x605/0xf50 fs/inode.c:2009 iput+0x35/0x40 fs/inode.c:1975 filename_unlinkat+0x466/0x730 fs/namei.c:5572 __do_sys_unlink fs/namei.c:5603 [inline] __se_sys_unlink fs/namei.c:5600 [inline] __x64_sys_unlink+0x46/0x70 fs/namei.c:5600 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7eff5359bec7 RSP: 002b:00007ffe99a6dce8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007eff5359bec7 RDX: 00007ffe99a6dd10 RSI: 00007ffe99a6dda0 RDI: 00007ffe99a6dda0 RBP: 00007ffe99a6dda0 R08: 00007ffe99a6eda0 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe99a6ee30 R13: 00007eff53632120 R14: 00000000001d986e R15: 00007ffe99a6ee70 rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g242909 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=157229 rcu: rcu_preempt kthread starved for 10500 jiffies! g242909 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:28216 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x10e9/0x6820 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7282 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30191 Comm: syz.0.5542 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:_find_first_zero_bit+0x48/0x80 lib/find_bit.c:149 Code: eb 0d 48 83 c3 40 48 83 c7 08 48 39 c3 73 25 48 89 fa 48 c1 ea 03 80 3c 2a 00 75 28 48 8b 17 48 83 f2 ff 74 dd f3 48 0f bc d2 <48> 01 d3 48 39 d8 48 0f 47 c3 48 83 c4 10 5b 5d e9 13 13 95 06 e9 RSP: 0018:ffffc90007d4fc28 EFLAGS: 00000002 RAX: 0000000000000002 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000002 RSI: 0000000000000002 RDI: ffff8880236e97d0 RBP: dffffc0000000000 R08: 0000000000000000 R09: fffff52000fa9f7c R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000002 R14: 0000000000000007 R15: ffff8880a8474a00 FS: 00007f93640d06c0(0000) GS:ffff888124476000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f93631ea4c0 CR3: 00000000abf6f000 CR4: 00000000003526f0 Call Trace: find_first_zero_bit include/linux/find.h:391 [inline] __mm_get_cid kernel/sched/sched.h:3865 [inline] mm_get_cid kernel/sched/sched.h:3880 [inline] sched_mm_cid_fork+0x506/0xef0 kernel/sched/core.c:10953 bprm_execve fs/exec.c:1771 [inline] bprm_execve+0x53f/0x1650 fs/exec.c:1724 do_execveat_common.isra.0+0x4a5/0x580 fs/exec.c:1846 __do_sys_execveat fs/exec.c:1941 [inline] __se_sys_execveat fs/exec.c:1934 [inline] __x64_sys_execveat+0xdf/0x130 fs/exec.c:1934 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f936319cdd9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f93640d0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142 RAX: ffffffffffffffda RBX: 00007f9363415fa0 RCX: 00007f936319cdd9 RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000005 RBP: 00007f9363232d69 R08: 0000000000001000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9363416038 R14: 00007f9363415fa0 R15: 00007ffe6ca1e3e8