INFO: rcu detected stall in vhost_task_fn (2)

Status: auto-obsoleted due to no activity on 2024/10/31 01:03
Subsystems: kvm net virt
[Documentation on labels]
First crash: 802d, last: 752d
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in vhost_task_fn (4) mm prio:high 1 2 144d 184d 0/29 auto-obsoleted due to no activity on 2026/07/01 18:23
upstream INFO: rcu detected stall in vhost_task_fn (3) virt kvm net 1 2 376d 390d 0/29 auto-obsoleted due to no activity on 2025/11/11 17:48
upstream INFO: rcu detected stall in vhost_task_fn mm 1 1 1029d 1029d 0/29 auto-obsoleted due to no activity on 2024/01/28 05:38

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5218/2:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=34673, q=350 ncpus=2)
task:syz-executor    state:R  running task     stack:20496 pid:5218  tgid:5218  ppid:5213   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:percpu_ref_tryget_many include/linux/percpu-refcount.h:244 [inline]
RIP: 0010:percpu_ref_tryget+0xa3/0x180 include/linux/percpu-refcount.h:266
Code: bf 00 00 00 00 00 fc ff df 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 df e8 e8 32 f7 ff 48 8b 03 a8 03 75 69 65 48 ff 00 <b3> 01 e8 36 a5 ac 09 85 c0 74 3a e8 7d 59 79 ff 84 c0 75 31 e8 24
RSP: 0018:ffffc9000397ee28 EFLAGS: 00000286
RAX: 0000607f46a5a6f8 RBX: ffff88805e664010 RCX: ffff888028471e00
RDX: dffffc0000000000 RSI: ffffffff8c3f8820 RDI: ffffffff8c3f87e0
RBP: 1ffff11005aacb32 R08: ffffffff934ec807 R09: 1ffffffff269d900
R10: dffffc0000000000 R11: fffffbfff269d901 R12: ffff88802d565990
R13: dffffc0000000000 R14: ffffffff82004634 R15: dffffc0000000000
 css_tryget include/linux/cgroup_refcnt.h:45 [inline]
 get_mem_cgroup_from_objcg+0xc8/0x150 include/linux/memcontrol.h:527
 obj_cgroup_charge_pages+0x81/0x200 mm/memcontrol.c:2658
 __memcg_kmem_charge_page+0xc8/0x1d0 mm/memcontrol.c:2687
 __alloc_pages_noprof+0x28c/0x6c0 mm/page_alloc.c:4717
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2263
 pagetable_alloc_noprof include/linux/mm.h:2868 [inline]
 __pte_alloc_one_noprof include/asm-generic/pgalloc.h:70 [inline]
 pte_alloc_one+0x88/0x5d0 arch/x86/mm/pgtable.c:33
 __pte_alloc+0x79/0x3a0 mm/memory.c:448
 copy_pte_range mm/memory.c:1106 [inline]
 copy_pmd_range+0x7ccd/0x8500 mm/memory.c:1252
 copy_pud_range mm/memory.c:1289 [inline]
 copy_p4d_range mm/memory.c:1313 [inline]
 copy_page_range+0x99f/0xe90 mm/memory.c:1411
 dup_mmap kernel/fork.c:749 [inline]
 dup_mm kernel/fork.c:1672 [inline]
 copy_mm+0x11ea/0x1f30 kernel/fork.c:1721
 copy_process+0x187a/0x3dc0 kernel/fork.c:2374
 kernel_clone+0x223/0x870 kernel/fork.c:2781
 __do_sys_clone kernel/fork.c:2924 [inline]
 __se_sys_clone kernel/fork.c:2908 [inline]
 __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2908
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fc025b6dc13
RSP: 002b:00007ffdc4c53e08 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc025b6dc13
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 00005555940da7d0 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000004e33e R14: 000000000004dfb9 R15: 00007ffdc4c53f90
 </TASK>
rcu: rcu_preempt kthread starved for 10540 jiffies! g34673 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:24912 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
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: 8204 Comm: vhost-8203 Not tainted 6.11.0-rc1-syzkaller-00154-gc0ecd6388360 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
RIP: 0010:hlock_class kernel/locking/lockdep.c:227 [inline]
RIP: 0010:mark_lock+0xa2/0x350 kernel/locking/lockdep.c:4655
Code: 00 8b 1b 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 00 c8 4e 93 be 08 00 00 00 e8 66 5e 87 00 48 0f a3 1d 4e aa de 11 <73> 10 48 69 c3 c8 00 00 00 48 8d 98 00 27 1d 93 eb 68 48 c7 c0 80
RSP: 0018:ffffc90000a18ac8 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000021 RCX: ffffffff81701daa
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff934ec800
RBP: 0000000000000009 R08: ffffffff934ec807 R09: 1ffffffff269d900
R10: dffffc0000000000 R11: fffffbfff269d901 R12: ffff88805d105a00
R13: dffffc0000000000 R14: 0000000000000200 R15: ffff88805d106508
FS:  00007fdbe6d6d6c0(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000002 CR3: 000000007efb4000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 mark_usage kernel/locking/lockdep.c:4598 [inline]
 __lock_acquire+0xc35/0x2040 kernel/locking/lockdep.c:5096
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759
 rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 rcu_read_lock include/linux/rcupdate.h:838 [inline]
 net_tx_action+0x725/0xa50 net/core/dev.c:5292
 handle_softirqs+0x2c4/0x970 kernel/softirq.c:554
 __do_softirq kernel/softirq.c:588 [inline]
 invoke_softirq kernel/softirq.c:428 [inline]
 __irq_exit_rcu+0xf4/0x1c0 kernel/softirq.c:637
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:649
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1043
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:173 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x11/0x70 kernel/kcov.c:207
Code: 5b e9 93 61 58 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 00 d7 03 00 <65> 8b 15 20 71 70 7e f7 c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74
RSP: 0018:ffffc900093078d0 EFLAGS: 00000246
RAX: ffffffff8141feb3 RBX: 0000000000000000 RCX: ffff88805d105a00
RDX: ffff88805d105a00 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900093079f8 R08: ffffffff8141fea9 R09: 1ffff1100fa7c615
R10: dffffc0000000000 R11: ffffed100fa7c616 R12: ffffc90009307a68
R13: ffffc90009307af0 R14: 0000000000000002 R15: 0000000000000000
 kernelmode_fixup_or_oops+0x53/0xf0 arch/x86/mm/fault.c:725
 __bad_area_nosemaphore+0x118/0x770 arch/x86/mm/fault.c:785
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x61d/0x8c0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:__get_user_nocheck_2+0xa/0x20 arch/x86/lib/getuser.S:120
Code: 01 ca c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 0f 01 cb 0f ae e8 <0f> b7 10 31 c0 0f 01 ca c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00
RSP: 0018:ffffc90009307b18 EFLAGS: 00050202
RAX: 0000000000000002 RBX: ffff88806a6c0290 RCX: dffffc0000000000
RDX: ffffc90014309000 RSI: 00000000000000cb RDI: 00000000000000cc
RBP: ffffc90009307b20 R08: ffffffff88fa9fd2 R09: 1ffffffff269d926
R10: dffffc0000000000 R11: fffffbfff269d927 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff88806a6c01e0 R15: ffff88806a6c01e0
 vhost_get_avail_idx+0xd5/0x410 drivers/vhost/vhost.c:1354
 vhost_enable_notify+0x315/0x5d0 drivers/vhost/vhost.c:2893
 vhost_transport_do_send_pkt+0x107c/0x1400 drivers/vhost/vsock.c:123
 vhost_run_work_list+0x145/0x1c0 drivers/vhost/vhost.c:407
 vhost_task_fn+0x267/0x3f0 kernel/vhost_task.c:49
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/02 00:57 upstream c0ecd6388360 1e9c4cf3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in vhost_task_fn
2024/07/25 04:28 upstream 786c8248dbd3 b24754ac .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in vhost_task_fn
2024/06/13 04:14 upstream cea2a26553ac 2aa5052f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: rcu detected stall in vhost_task_fn
* Struck through repros no longer work on HEAD.