syzbot |
sign-in | mailing list | source | docs |
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P20156/1:b..l (detected by 0, t=10502 jiffies, g=130089, q=5 ncpus=2) task:syz.7.3570 state:R running task stack:26544 pid:20156 ppid:8383 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_is_held_type+0x14e/0x190 kernel/locking/lockdep.c:5710 Code: 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 48 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e <41> 5f 5d c3 0f 0b 48 c7 c7 20 12 8c 8a e8 00 12 00 00 65 c7 05 75 RSP: 0018:ffffc90003e8f570 EFLAGS: 00000286 RAX: 0000000000000001 RBX: ffff888055654b02 RCX: a315fe5761a61900 RDX: ffff88807c25bb80 RSI: ffffffff8a8c23a0 RDI: ffffffff8adf0d20 RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff215ea48 R10: dffffc0000000000 R11: fffffbfff215ea49 R12: ffff888141256828 R13: ffffc90003e8f5e0 R14: ffffc90003e8f5c8 R15: ffff88807c25c688 xa_head include/linux/xarray.h:1182 [inline] xas_start+0x292/0x770 lib/xarray.c:188 xas_load lib/xarray.c:235 [inline] xa_load+0x122/0x2e0 lib/xarray.c:1463 memcg_list_lru_allocated mm/list_lru.c:469 [inline] memcg_list_lru_alloc+0x13a/0xb10 mm/list_lru.c:483 memcg_slab_pre_alloc_hook mm/slab.h:494 [inline] slab_pre_alloc_hook+0x2b2/0x310 mm/slab.h:715 slab_alloc_node mm/slub.c:3279 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc_lru+0x49/0x2e0 mm/slub.c:3390 __d_alloc+0x31/0x700 fs/dcache.c:1774 d_alloc fs/dcache.c:1854 [inline] d_alloc_parallel+0xdc/0x1530 fs/dcache.c:2647 __lookup_slow+0x134/0x3f0 fs/namei.c:1683 lookup_one_len+0x19d/0x2d0 fs/namei.c:2748 start_creating+0x184/0x310 fs/debugfs/inode.c:377 __debugfs_create_file+0x6f/0x510 fs/debugfs/inode.c:422 kvm_create_vm_debugfs+0x6da/0x980 virt/kvm/kvm_main.c:1104 kvm_create_vm virt/kvm/kvm_main.c:1239 [inline] kvm_dev_ioctl_create_vm virt/kvm/kvm_main.c:5010 [inline] kvm_dev_ioctl+0x1404/0x1800 virt/kvm/kvm_main.c:5052 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fdec779bf79 RSP: 002b:00007fdec85f7028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fdec7a15fa0 RCX: 00007fdec779bf79 RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000008 RBP: 00007fdec78327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fdec7a16038 R14: 00007fdec7a15fa0 R15: 00007ffeb0cd3728 </TASK> rcu: rcu_preempt kthread starved for 10378 jiffies! g130089 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:27736 pid:16 ppid:2 flags:0x00004000 Call Trace: <TASK> context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 </TASK> rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:741
| Time | Kernel | Commit | Syzkaller | Config | Log | Report | Syz repro | C repro | VM info | Assets (help?) | Manager | Title |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2026/02/12 10:22 | linux-6.1.y | 8ce36b2849ef | 76a109e2 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci2-linux-6-1-kasan | INFO: rcu detected stall in kvm_dev_ioctl | ||
| 2026/01/10 12:34 | linux-6.1.y | 50cbba13faa2 | d6526ea3 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci2-linux-6-1-kasan | INFO: rcu detected stall in kvm_dev_ioctl |