rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=139569, q=28 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10500 (4295265172-4295254672), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10500 jiffies! g139569 f0x2 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:26552 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5209 [inline] __schedule+0x8fc/0xda0 kernel/sched/core.c:6521 schedule+0xcb/0x190 kernel/sched/core.c:6597 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1935 rcu_gp_fqs_loop+0x309/0x1070 kernel/rcu/tree.c:1660 rcu_gp_kthread+0xa5/0x390 kernel/rcu/tree.c:1859 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 25789 Comm: syz-executor.3 Not tainted 6.1.0-rc7-syzkaller-00103-gef4d3ea40565 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:466 [inline] RIP: 0010:lock_is_held_type+0x117/0x190 kernel/locking/lockdep.c:5712 Code: c0 31 ed 44 39 f0 40 0f 94 c5 eb 05 bd 01 00 00 00 48 c7 c7 a0 a2 0d 8b e8 76 14 00 00 b8 ff ff ff ff 65 0f c1 05 e9 6b 5b 75 <83> f8 01 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 RSP: 0018:ffffc90000007cd8 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000003 RCX: 0000000080010002 RDX: ffff888023f457c0 RSI: ffffffff8b0da2a0 RDI: ffffffff8b68fcc0 RBP: 0000000000000001 R08: ffffffff817bca06 R09: ffff88801eaad340 R10: ffffed1003d55a6b R11: 1ffff11003d55a68 R12: 0000000000000046 R13: ffff888023f457c0 R14: 00000000ffffffff R15: ffff8880b982a4d8 FS: 00005555561c1400(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f453010e263 CR3: 0000000019f10000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:283 [inline] __run_hrtimer kernel/time/hrtimer.c:1651 [inline] __hrtimer_run_queues+0x2c1/0xa60 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x3a6/0xfd0 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline] __sysvec_apic_timer_interrupt+0xf9/0x280 arch/x86/kernel/apic/apic.c:1113 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1107 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:___slab_alloc+0xc95/0xeb0 Code: 00 00 00 00 9c 8f 44 24 58 f7 44 24 58 00 02 00 00 0f 85 96 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 60 0f 85 49 01 00 00 4c 89 f8 48 83 c4 68 5b 41 5c 41 RSP: 0018:ffffc90003a7f980 EFLAGS: 00000206 RAX: 5d00934a4b50fb00 RBX: ffff8880b983da00 RCX: ffffffff816c4e6a RDX: dffffc0000000000 RSI: ffffffff8b0d9120 RDI: ffffffff8b68fcc0 RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff20e4c3d R10: fffffbfff20e4c3d R11: 1ffffffff20e4c3c R12: 00000000ffffffff R13: ffff888012841b40 R14: 0000000000000246 R15: ffff88803d17ba00 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x252/0x310 mm/slub.c:3437 kmalloc_trace+0x26/0x60 mm/slab_common.c:1045 kmalloc include/linux/slab.h:553 [inline] kzalloc include/linux/slab.h:689 [inline] smk_fetch+0x91/0x140 security/smack/smack_lsm.c:291 smack_d_instantiate+0x7b0/0xa10 security/smack/smack_lsm.c:3466 security_d_instantiate+0xa5/0x100 security/security.c:2063 d_instantiate_new+0x61/0x110 fs/dcache.c:2053 ext4_add_nondir+0x200/0x260 fs/ext4/namei.c:2777 ext4_symlink+0x925/0xb40 fs/ext4/namei.c:3407 vfs_symlink+0x246/0x3d0 fs/namei.c:4401 do_symlinkat+0x209/0x610 fs/namei.c:4430 __do_sys_symlinkat fs/namei.c:4447 [inline] __se_sys_symlinkat fs/namei.c:4444 [inline] __x64_sys_symlinkat+0x95/0xa0 fs/namei.c:4444 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f453008ba17 Code: 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0a 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd5ed82c78 EFLAGS: 00000206 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f453008ba17 RDX: 00007f45300e7b9e RSI: 00000000ffffff9c RDI: 00007ffd5ed82d40 RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffd5ed82b10 R10: 00007ffd5ed829c7 R11: 0000000000000206 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffd5ed82d40