rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12465/1:b..l rcu: (detected by 0, t=10502 jiffies, g=107317, q=414 ncpus=2) task:syz.1.1714 state:R running task stack:27464 pid:12465 tgid:12462 ppid:5808 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_common+0x42/0xc0 kernel/sched/core.c:7369 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:198 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] avc_reclaim_node security/selinux/avc.c:488 [inline] avc_alloc_node+0x3f5/0x670 security/selinux/avc.c:507 avc_update_node.isra.0+0x48/0xb90 security/selinux/avc.c:841 avc_denied+0x141/0x190 security/selinux/avc.c:1007 avc_has_extended_perms+0xddf/0x1080 security/selinux/avc.c:1085 ioctl_has_perm.constprop.0.isra.0+0x376/0x540 security/selinux/hooks.c:3898 selinux_file_ioctl+0x13b/0x290 security/selinux/hooks.c:3946 security_file_ioctl+0xfb/0x230 security/security.c:2512 __do_sys_ioctl fs/ioctl.c:591 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0xb7/0x210 fs/ioctl.c:583 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: 0033:0x7f1fcb99c4ab RSP: 002b:00007f1fcc7abf00 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f1fcb99c4ab RDX: 00007f1fcc7acfd0 RSI: 0000000080085502 RDI: 0000000000000005 RBP: 00007f1fcc7acfd0 R08: 0000000000000009 R09: 00007f1fcc7abfc8 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000080085502 R13: 0000000800000000 R14: 0000000000000009 R15: 00007f1fcba50ede rcu: rcu_preempt kthread starved for 10498 jiffies! g107317 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task 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: 12468 Comm: syz.5.1715 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline] RIP: 0010:lock_release kernel/locking/lockdep.c:5888 [inline] RIP: 0010:lock_release+0x8e/0x310 kernel/locking/lockdep.c:5875 Code: 00 65 4c 8b 25 bb f5 2c 12 41 8b bc 24 8c 0b 00 00 85 ff 0f 85 21 01 00 00 48 81 3b c0 a7 18 94 0f 84 14 01 00 00 9c 41 5e fa <48> c7 c7 06 89 03 8e e8 56 4e af 09 65 ff 05 f7 3c 2d 12 8b 35 2d RSP: 0018:ffffc90000a08e28 EFLAGS: 00000087 RAX: 0000000000000000 RBX: ffff8880b85284d8 RCX: ffffffff81f4b684 RDX: 0000000000000000 RSI: ffffffff8c1b7ce0 RDI: 0000000000000000 RBP: ffffffff81f4bbf3 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffff8880395e0000 R13: 0000000000000001 R14: 0000000000000087 R15: ffff8880b8528650 FS: 00007f12c40316c0(0000) GS:ffff888124403000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2de14ff8 CR3: 000000007cbe5000 CR4: 00000000003526f0 Call Trace: __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_irqrestore+0x1a/0x80 kernel/locking/spinlock.c:198 __run_hrtimer kernel/time/hrtimer.c:1926 [inline] __hrtimer_run_queues+0x383/0xa00 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:finish_task_switch.isra.0+0x2d3/0x1010 kernel/sched/core.c:5244 Code: 2f 0a 00 00 41 c7 87 e0 0d 00 00 00 00 00 00 e9 0f 04 00 00 49 8d 7f 48 e8 da 57 c1 09 e8 05 72 3b 00 fb 48 8d bb a8 16 00 00 <48> b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 04 02 84 RSP: 0018:ffffc900031674c8 EFLAGS: 00000206 RAX: 00000000000168dd RBX: ffff8880395e0000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8df45eac RDI: ffff8880395e16a8 RBP: ffffc90003167520 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: ffffffff81d5a672 R12: ffff88802a210000 R13: 0000000000000001 R14: ffffffff90dbb2c4 R15: ffff8880b853b200 context_switch kernel/sched/core.c:5390 [inline] __schedule+0x10f1/0x6820 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7282 schedule_timeout+0x1b2/0x280 kernel/time/sleep_timeout.c:75 unix_wait_for_peer+0x268/0x2a0 net/unix/af_unix.c:1622 unix_dgram_sendmsg+0x1696/0x1810 net/unix/af_unix.c:2251 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x9e1/0xb70 net/socket.c:2698 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2752 __sys_sendmmsg+0x205/0x430 net/socket.c:2841 __do_sys_sendmmsg net/socket.c:2868 [inline] __se_sys_sendmmsg net/socket.c:2865 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2865 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: 0033:0x7f12c319c819 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:00007f12c4031028 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f12c3415fa0 RCX: 00007f12c319c819 RDX: 0400000000000041 RSI: 0000200000000000 RDI: 0000000000000004 RBP: 00007f12c3232c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f12c3416038 R14: 00007f12c3415fa0 R15: 00007ffeb3afe018