rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P18655/1:b..l rcu: (detected by 1, t=10502 jiffies, g=98409, q=296 ncpus=2) task:syz.6.2976 state:R running task stack:25032 pid:18655 tgid:18654 ppid:7055 task_flags:0x400140 flags:0x00024000 Call Trace: context_switch kernel/sched/core.c:5313 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6696 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7019 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x44/0x3e0 kernel/locking/lockdep.c:5882 Code: 8b 05 20 eb ff 10 48 89 44 24 28 0f 1f 44 00 00 65 8b 05 23 eb ff 10 83 f8 08 0f 83 9a 02 00 00 89 c0 48 0f a3 05 cc 27 03 0e <73> 16 e8 75 e2 08 00 84 c0 75 0d f6 05 9e 1f ed 0d 01 0f 84 ad 02 RSP: 0018:ffffc900044ff310 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffffffff903df801 RCX: bef3fa3a85eea400 RDX: ffffc900044ff401 RSI: ffffffff81729c65 RDI: ffffffff8e13ee60 RBP: dffffc0000000000 R08: ffffc900044ff7b8 R09: 0000000000000000 R10: ffffc900044ff498 R11: fffff5200089fe95 R12: ffffc900044ff7c8 R13: ffffffff81729c65 R14: ffffffff8e13ee60 R15: ffffffff81729c65 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 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:3100 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3220 slab_free_hook mm/slub.c:2345 [inline] slab_free mm/slub.c:4648 [inline] kmem_cache_free+0x309/0x400 mm/slub.c:4750 __io_req_caches_free+0x8f/0x140 io_uring/io_uring.c:2734 io_queue_deferred+0x81/0x400 io_uring/io_uring.c:542 io_drain_req+0x3a5/0x560 io_uring/io_uring.c:1699 io_submit_sqe io_uring/io_uring.c:2244 [inline] io_submit_sqes+0x1111/0x1d10 io_uring/io_uring.c:2362 __do_sys_io_uring_enter io_uring/io_uring.c:3429 [inline] __se_sys_io_uring_enter+0x2df/0x2b20 io_uring/io_uring.c:3363 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: 0033:0x7fa39838e929 RSP: 002b:00007fa3991ba038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007fa3985b5fa0 RCX: 00007fa39838e929 RDX: 0000000000000000 RSI: 00000000000047ba RDI: 0000000000000005 RBP: 00007fa398410b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fa3985b5fa0 R15: 00007fff003fe238 rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g98409 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=112788 rcu: rcu_preempt kthread starved for 10500 jiffies! g98409 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:26904 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5313 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6696 __schedule_loop kernel/sched/core.c:6774 [inline] schedule+0x165/0x360 kernel/sched/core.c:6789 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2060 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2262 kthread+0x70e/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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5836 Comm: udevd Not tainted 6.16.0-rc2-next-20250618-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:check_wait_context kernel/locking/lockdep.c:4857 [inline] RIP: 0010:__lock_acquire+0x384/0xd20 kernel/locking/lockdep.c:5190 Code: 22 83 3d 22 63 03 0e 00 75 19 90 48 c7 c7 35 99 b7 8d 48 c7 c6 a2 06 a7 8d e8 68 cd e5 ff 90 0f 0b 90 90 90 31 c0 48 8b 3c 24 <0f> b6 98 c4 00 00 00 41 8b 46 20 25 ff 1f 00 00 48 0f a3 05 74 a8 RSP: 0018:ffffc90000007b30 EFLAGS: 00000006 RAX: ffffffff93529cc0 RBX: ffff888027d47300 RCX: 0000000000000f02 RDX: 0000000000080000 RSI: 0000000000004000 RDI: ffff888031d49e00 RBP: 0000000000000f02 R08: 0000000000000000 R09: ffffffff89896794 R10: dffffc0000000000 R11: ffffffff898966d0 R12: 0000000000004000 R13: 0000000000000000 R14: ffff888031d4a918 R15: ffff888031d4a8f0 FS: 00007f1263550880(0000) GS:ffff888125c3d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000000b000 CR3: 00000000345c8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 000000000000003c DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xc4/0xc90 net/sched/sch_taprio.c:924 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x529/0xc60 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+0x10b/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:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5896 Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 8b e8 ff 10 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000414f210 EFLAGS: 00000206 RAX: 75fb1d74d3989000 RBX: 0000000000000202 RCX: 75fb1d74d3989000 RDX: 0000000000000001 RSI: ffffffff8db7aaf9 RDI: ffffffff8be2f5e0 RBP: ffff888031d4a918 R08: ffffc9000414f8f0 R09: 0000000000000000 R10: ffffc9000414f398 R11: fffff52000829e75 R12: 0000000000000001 R13: 0000000000000001 R14: ffffffff8e13ee60 R15: ffff888031d49e00 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4648 [inline] kmem_cache_free+0x18f/0x400 mm/slub.c:4750 free_buffer_head+0x55/0x220 fs/buffer.c:3048 try_to_free_buffers+0x232/0x2d0 fs/buffer.c:2989 block_invalidate_folio+0x5f7/0x730 fs/buffer.c:1680 folio_invalidate mm/truncate.c:140 [inline] truncate_cleanup_folio+0x2d8/0x430 mm/truncate.c:160 truncate_inode_pages_range+0x233/0xda0 mm/truncate.c:379 kill_bdev block/bdev.c:91 [inline] blkdev_flush_mapping+0x108/0x270 block/bdev.c:712 blkdev_put_whole block/bdev.c:719 [inline] bdev_release+0x417/0x650 block/bdev.c:1144 blkdev_release+0x15/0x20 block/fops.c:684 __fput+0x44c/0xa70 fs/file_table.c:468 fput_close_sync+0x119/0x200 fs/file_table.c:573 __do_sys_close fs/open.c:1586 [inline] __se_sys_close fs/open.c:1571 [inline] __x64_sys_close+0x7f/0x110 fs/open.c:1571 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: 0033:0x7f1262ea7407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: 002b:00007fff6b2c11c0 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 00007f1263550880 RCX: 00007f1262ea7407 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008 RBP: 00007f12635506e8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 R13: 0000558a91b843e0 R14: 0000000000000008 R15: 0000558a91b89ee0