rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7333/1:b..l rcu: (detected by 0, t=10502 jiffies, g=21165, q=57 ncpus=2) task:syz-executor.5 state:R running task stack:28240 pid:7333 ppid:5056 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x1d15/0x5790 kernel/sched/core.c:6669 preempt_schedule_irq+0x52/0x90 kernel/sched/core.c:6981 irqentry_exit+0x35/0x80 kernel/entry/common.c:433 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x20 kernel/kcov.c:303 Code: d6 fe ff ff 66 0f 1f 44 00 00 f3 0f 1e fa 48 8b 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 b8 fe ff ff 0f 1f 84 00 00 00 00 00 0f 1e fa 48 8b 0c 24 89 f2 89 fe bf 05 00 00 00 e9 9a fe ff ff RSP: 0018:ffffc9000371f910 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff888020718000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000371fa20 R08: 0000000000000004 R09: 0000000000001772 R10: 0000000000001772 R11: 0000000000094001 R12: 0000000000000001 R13: ffff88809b96b680 R14: 0000000000001772 R15: dffffc0000000000 prepend_path+0x6b5/0xf20 fs/d_path.c:180 d_absolute_path+0xf3/0x1a0 fs/d_path.c:233 tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline] tomoyo_realpath_from_path+0x269/0x600 security/tomoyo/realpath.c:271 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x230/0x430 security/tomoyo/file.c:822 tomoyo_path_symlink+0x98/0xe0 security/tomoyo/tomoyo.c:211 security_path_symlink+0xe3/0x160 security/security.c:1747 do_symlinkat+0x10a/0x2e0 fs/namei.c:4499 __do_sys_symlinkat fs/namei.c:4517 [inline] __se_sys_symlinkat fs/namei.c:4514 [inline] __x64_sys_symlinkat+0x97/0xc0 fs/namei.c:4514 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f5970e8baa7 RSP: 002b:00007ffe23c8c658 EFLAGS: 00000206 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5970e8baa7 RDX: 00007f5970ee7d42 RSI: 00000000ffffff9c RDI: 00007f5970ee68cb RBP: 0000000000000000 R08: 0000000000000000 R09: 00007ffe23c8c0d0 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000001 R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffe23c8c720 rcu: rcu_preempt kthread starved for 10535 jiffies! g21165 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:28352 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x1d15/0x5790 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 schedule_timeout+0x14e/0x2b0 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1609 rcu_gp_kthread+0x23a/0x360 kernel/rcu/tree.c:1808 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 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: 7341 Comm: syz-executor.2 Not tainted 6.4.0-rc2-next-20230515-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 RIP: 0010:kvm_wait+0xa8/0x110 arch/x86/kernel/kvm.c:1064 Code: fa 83 e2 07 38 d0 7f 04 84 c0 75 66 0f b6 07 40 38 c6 74 1b 48 83 c4 10 c3 c3 e8 73 a8 52 00 66 90 0f 00 2d ba 72 11 09 fb f4 <48> 83 c4 10 c3 66 90 0f 00 2d aa 72 11 09 f4 48 83 c4 10 c3 89 74 RSP: 0018:ffffc900001e0b58 EFLAGS: 00000246 RAX: 000000000002bbe4 RBX: 0000000000000000 RCX: 1ffffffff22b06a6 RDX: 0000000000000000 RSI: 0000000000000101 RDI: 0000000000000000 RBP: ffff8880a72948f0 R08: 0000000000000001 R09: fffffbfff22a75b8 R10: 0000000000000001 R11: ffff8880b993d198 R12: 0000000000000000 R13: ffffed1014e5291e R14: 0000000000000001 R15: ffff8880b993d440 FS: 00007fa2b6a28700(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000201c5030 CR3: 0000000019b44000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_wait arch/x86/include/asm/paravirt.h:598 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x8cb/0xb50 kernel/locking/qspinlock.c:511 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x204/0x2b0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:350 [inline] fq_pie_timer+0x96/0x2a0 net/sched/sch_fq_pie.c:377 call_timer_fn+0x1a0/0x580 kernel/time/timer.c:1700 expire_timers+0x234/0x330 kernel/time/timer.c:1751 __run_timers kernel/time/timer.c:2022 [inline] __run_timers kernel/time/timer.c:1995 [inline] run_timer_softirq+0x326/0x910 kernel/time/timer.c:2035 __do_softirq+0x1d4/0x905 kernel/softirq.c:553 invoke_softirq kernel/softirq.c:427 [inline] __irq_exit_rcu kernel/softirq.c:632 [inline] irq_exit_rcu+0xb7/0x120 kernel/softirq.c:644 sysvec_apic_timer_interrupt+0x97/0xc0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645 RIP: 0010:__put_user_nocheck_4+0x4/0x20 arch/x86/lib/putuser.S:99 Code: 00 00 00 00 00 90 f3 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb 89 01 31 c9 0f 01 ca c3 0f 1f 80 00 00 00 00 f3 0f 1e fa 0f 1e fa 0f 01 cb 89 01 31 c9 0f 01 ca c3 66 66 2e 0f 1f 84 00 RSP: 0018:ffffc9000384fa00 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000201c57b0 RDX: 0000000000040000 RSI: ffffffff8805fccc RDI: 0000000000000005 RBP: ffffc9000384fdb0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000001 R12: 0000000000000000 R13: 00000000201c57b0 R14: 0000000000000002 R15: 0000000000000000 ____sys_recvmsg+0x2f7/0x5a0 net/socket.c:2735 ___sys_recvmsg+0xf2/0x180 net/socket.c:2764 do_recvmmsg+0x25e/0x6f0 net/socket.c:2858 __sys_recvmmsg net/socket.c:2937 [inline] __do_sys_recvmmsg net/socket.c:2960 [inline] __se_sys_recvmmsg net/socket.c:2953 [inline] __x64_sys_recvmmsg+0x20f/0x260 net/socket.c:2953 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fa2b5c8c169 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fa2b6a28168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007fa2b5dac050 RCX: 00007fa2b5c8c169 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000003 RBP: 00007fa2b5ce7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff5e4327bf R14: 00007fa2b6a28300 R15: 0000000000022000 sched: RT throttling activated vkms_vblank_simulate: vblank timer overrun