rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=c0d/1/0x4000000000000000 softirq=20466/20466 fqs=0 (detected by 0, t=10502 jiffies, g=24945, q=405) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4190 Comm: syz-executor Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:hlock_class kernel/locking/lockdep.c:197 [inline] RIP: 0010:__lock_acquire+0x10b7/0x7c60 kernel/locking/lockdep.c:5008 Code: 03 89 c3 81 e3 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 c0 70 fb 8f be 08 00 00 00 e8 91 1d 60 00 48 0f a3 1d 59 65 9f 0e <0f> 83 87 01 00 00 48 8d 04 5b c1 e0 06 48 8d 98 80 ef 93 8f 49 b8 RSP: 0018:ffffc90000dd08c0 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000015 RCX: ffffffff815c0b5f RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffb70c0 RBP: ffffc90000dd0b10 R08: dffffc0000000000 R09: fffffbfff1ff6e19 R10: fffffbfff1ff6e19 R11: 1ffffffff1ff6e18 R12: 00000000c971da1e R13: ffff88801a399dc0 R14: 00000000ec1655f8 R15: ffff88801a39a8f8 FS: 000055556e66d500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7f1c2812f8 CR3: 0000000062232000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:363 [inline] advance_sched+0x47/0x940 net/sched/sch_taprio.c:716 __run_hrtimer kernel/time/hrtimer.c:1690 [inline] __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b RSP: 0018:ffffc90002ecf6c0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ed73a459a480bb00 RDX: 0000000000000000 RSI: ffffffff8a0b2860 RDI: ffffffff8a599340 RBP: ffffc90002ecf7e0 R08: dffffc0000000000 R09: fffffbfff1ff6e19 R10: fffffbfff1ff6e19 R11: 1ffffffff1ff6e18 R12: ffffffff8c11c360 R13: 1ffff920005d9ee4 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] is_bpf_text_address+0x1d/0x270 kernel/bpf/core.c:725 kernel_text_address kernel/extable.c:151 [inline] __kernel_text_address+0x9a/0x100 kernel/extable.c:105 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:725 [inline] lsm_file_alloc security/security.c:574 [inline] security_file_alloc+0x30/0x110 security/security.c:1530 __alloc_file+0xc2/0x240 fs/file_table.c:137 alloc_empty_file+0x90/0x180 fs/file_table.c:181 alloc_file+0x5b/0x4f0 fs/file_table.c:223 alloc_file_pseudo+0x17a/0x1f0 fs/file_table.c:263 sock_alloc_file+0xb3/0x240 net/socket.c:462 sock_map_fd net/socket.c:486 [inline] __sys_socket+0x11d/0x170 net/socket.c:1588 __do_sys_socket net/socket.c:1593 [inline] __se_sys_socket net/socket.c:1591 [inline] __x64_sys_socket+0x76/0x80 net/socket.c:1591 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f7f1c090a87 Code: f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 b8 29 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcac35bf48 EFLAGS: 00000206 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f7f1c090a87 RDX: 0000000000000006 RSI: 0000000000000001 RDI: 000000000000000a RBP: 00007ffcac35c67c R08: 00007ffcac35bf6c R09: 0079746972756365 R10: 00007ffcac35bfd0 R11: 0000000000000206 R12: 00007f7f1c282ca0 R13: 00000000000927c0 R14: 0000000000086376 R15: 00007f7f1c284e60 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g24945 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=15065 rcu: rcu_preempt kthread starved for 10502 jiffies! g24945 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:27008 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4190 Comm: syz-executor Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:mark_usage kernel/locking/lockdep.c:4464 [inline] RIP: 0010:__lock_acquire+0xb70/0x7c60 kernel/locking/lockdep.c:4966 Code: 48 c7 c0 48 a2 69 8d 48 c1 e8 03 42 0f b6 04 00 84 c0 0f 85 bb 61 00 00 83 3d 33 9c 0d 0c 00 0f 84 95 0f 00 00 83 7c 24 68 00 <0f> 84 d4 01 00 00 48 8b 44 24 58 42 0f b6 04 00 84 c0 0f 85 ee 5c RSP: 0018:ffffc90000dd08e0 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff88801a39a8a8 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffb70c8 RBP: ffffc90000dd0b30 R08: dffffc0000000000 R09: fffffbfff1ff6e1a R10: fffffbfff1ff6e1a R11: 1ffffffff1ff6e19 R12: ffff88801a39a8f8 R13: ffff88801a399dc0 R14: 0000000000000001 R15: ffff88801a39a8d8 FS: 000055556e66d500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7f1c2812f8 CR3: 0000000062232000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline] _raw_spin_lock_irq+0x9f/0xe0 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1694 [inline] __hrtimer_run_queues+0x5ff/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b RSP: 0018:ffffc90002ecf6c0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ed73a459a480bb00 RDX: 0000000000000000 RSI: ffffffff8a0b2860 RDI: ffffffff8a599340 RBP: ffffc90002ecf7e0 R08: dffffc0000000000 R09: fffffbfff1ff6e19 R10: fffffbfff1ff6e19 R11: 1ffffffff1ff6e18 R12: ffffffff8c11c360 R13: 1ffff920005d9ee4 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] is_bpf_text_address+0x1d/0x270 kernel/bpf/core.c:725 kernel_text_address kernel/extable.c:151 [inline] __kernel_text_address+0x9a/0x100 kernel/extable.c:105 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3233 kmem_cache_zalloc include/linux/slab.h:725 [inline] lsm_file_alloc security/security.c:574 [inline] security_file_alloc+0x30/0x110 security/security.c:1530 __alloc_file+0xc2/0x240 fs/file_table.c:137 alloc_empty_file+0x90/0x180 fs/file_table.c:181 alloc_file+0x5b/0x4f0 fs/file_table.c:223 alloc_file_pseudo+0x17a/0x1f0 fs/file_table.c:263 sock_alloc_file+0xb3/0x240 net/socket.c:462 sock_map_fd net/socket.c:486 [inline] __sys_socket+0x11d/0x170 net/socket.c:1588 __do_sys_socket net/socket.c:1593 [inline] __se_sys_socket net/socket.c:1591 [inline] __x64_sys_socket+0x76/0x80 net/socket.c:1591 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f7f1c090a87 Code: f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 b8 29 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcac35bf48 EFLAGS: 00000206 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f7f1c090a87 RDX: 0000000000000006 RSI: 0000000000000001 RDI: 000000000000000a RBP: 00007ffcac35c67c R08: 00007ffcac35bf6c R09: 0079746972756365 R10: 00007ffcac35bfd0 R11: 0000000000000206 R12: 00007f7f1c282ca0 R13: 00000000000927c0 R14: 0000000000086376 R15: 00007f7f1c284e60