syzbot


INFO: task hung in kvm_mmu_uninit_tdp_mmu

Status: premoderation: reported on 2025/06/21 02:10
Reported-by: syzbot+d3c18315969ea1e41e93@syzkaller.appspotmail.com
First crash: 3d21h, last: 7h25m

Sample crash report:
INFO: task syz.1.83:580 blocked for more than 123 seconds.
      Not tainted 6.12.30-syzkaller-g9d80e3254812 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.83        state:D stack:0     pid:580   tgid:580   ppid:288    flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5924 [inline]
 __schedule+0x145b/0x1f10 kernel/sched/core.c:7750
 __schedule_loop kernel/sched/core.c:7831 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7846
 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7903
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x836/0x1b60 kernel/locking/mutex.c:786
 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1117
 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:270
 rcu_barrier+0x4d/0x530 kernel/rcu/tree.c:4574
 kvm_mmu_uninit_tdp_mmu+0x1df/0x210 arch/x86/kvm/mmu/tdp_mmu.c:51
 kvm_mmu_uninit_vm+0x27/0x60 arch/x86/kvm/mmu/mmu.c:6572
 kvm_arch_destroy_vm+0x383/0x410 arch/x86/kvm/x86.c:12898
 kvm_destroy_vm virt/kvm/kvm_main.c:1355 [inline]
 kvm_put_kvm+0xb04/0x12b0 virt/kvm/kvm_main.c:1391
 kvm_vm_release+0x47/0x70 virt/kvm/kvm_main.c:1414
 __fput+0x1fb/0xa00 fs/file_table.c:431
 ____fput+0x20/0x30 fs/file_table.c:459
 task_work_run+0x1e0/0x250 kernel/task_work.c:240
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x9b4/0x2630 kernel/exit.c:944
 do_group_exit+0x22a/0x300 kernel/exit.c:1094
 get_signal+0x139d/0x14f0 kernel/signal.c:2934
 arch_do_signal_or_restart+0x96/0x720 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f8995dc11e5
RSP: 002b:00007f8996b51f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f8995fb5fa0 RCX: 00007f8995dc11e5
RDX: 00007f8996b51fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f8995e10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f8995fb5fa0 R15: 00007ffc4a6ce1f8
 </TASK>
INFO: task syz.3.311:1278 blocked for more than 125 seconds.
      Not tainted 6.12.30-syzkaller-g9d80e3254812 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.311       state:D stack:0     pid:1278  tgid:1278  ppid:294    flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5924 [inline]
 __schedule+0x145b/0x1f10 kernel/sched/core.c:7750
 __schedule_loop kernel/sched/core.c:7831 [inline]
 schedule+0xc6/0x240 kernel/sched/core.c:7846
 schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common+0x359/0x630 kernel/sched/completion.c:127
 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
 rcu_barrier+0x415/0x530 kernel/rcu/tree.c:4642
 netdev_run_todo+0x10e/0xcb0 net/core/dev.c:10864
 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152
 tun_detach drivers/net/tun.c:704 [inline]
 tun_chr_close+0xc5/0x150 drivers/net/tun.c:3517
 __fput+0x1fb/0xa00 fs/file_table.c:431
 ____fput+0x20/0x30 fs/file_table.c:459
 task_work_run+0x1e0/0x250 kernel/task_work.c:240
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0x9b4/0x2630 kernel/exit.c:944
 do_group_exit+0x22a/0x300 kernel/exit.c:1094
 get_signal+0x139d/0x14f0 kernel/signal.c:2934
 arch_do_signal_or_restart+0x96/0x720 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f4b64dc11e5
RSP: 002b:00007f4b65b65f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f4b64fb5fa0 RCX: 00007f4b64dc11e5
RDX: 00007f4b65b65fc0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f4b64e10b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f4b64fb5fa0 R15: 00007ffdcddc7e38
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.30-syzkaller-g9d80e3254812 #0 0af3bb1b2b1f0d17039a87b1bb907b41f79d5270
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41
 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:229 [inline]
 watchdog+0xd8f/0xed0 kernel/hung_task.c:385
 kthread+0x2ca/0x370 kernel/kthread.c:389
 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 20 Comm: rcuop/0 Not tainted 6.12.30-syzkaller-g9d80e3254812 #0 0af3bb1b2b1f0d17039a87b1bb907b41f79d5270
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:arch_stack_walk+0x12a/0x170 arch/x86/kernel/stacktrace.c:27
Code: ff ff ff 4c 89 ff e8 15 74 06 00 48 85 c0 74 32 48 89 df 48 89 c6 4d 89 f3 41 ba eb c4 0e 81 45 03 53 f1 74 02 0f 0b 41 ff d3 <0f> 1f 00 84 c0 74 11 4c 89 ff e8 37 75 06 00 83 bd 78 ff ff ff 00
RSP: 0018:ffffc90000230248 EFLAGS: 00000282
RAX: 0000000000000001 RBX: ffffc90000230300 RCX: 0000000000230200
RDX: dffffc0000000000 RSI: ffffffff814fc116 RDI: ffffc90000230300
RBP: ffffc900002302d0 R08: ffffc90000230310 R09: ffffc90000230308
R10: 000000000000000e R11: ffffffff817401b0 R12: ffff888103660000
R13: 0000000000000100 R14: ffffffff817401b0 R15: ffffc90000230248
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffccbc12ff8 CR3: 000000010e252000 CR4: 00000000003526b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 stack_trace_save+0x9d/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 kasan_save_alloc_info+0x40/0x50 mm/kasan/generic.c:565
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4164 [inline]
 slab_alloc_node mm/slub.c:4213 [inline]
 kmem_cache_alloc_noprof+0x131/0x3a0 mm/slub.c:4222
 skb_clone+0x229/0x460 net/core/skbuff.c:2094
 deliver_clone net/bridge/br_forward.c:125 [inline]
 maybe_deliver net/bridge/br_forward.c:190 [inline]
 br_flood+0x4ed/0x730 net/bridge/br_forward.c:236
 br_handle_frame_finish+0x12bb/0x1720 net/bridge/br_input.c:215
 nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
 br_handle_frame+0x5a6/0xba0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xf48/0x3940 net/core/dev.c:5651
 __netif_receive_skb_one_core net/core/dev.c:5755 [inline]
 __netif_receive_skb net/core/dev.c:5870 [inline]
 process_backlog+0x3e5/0xae0 net/core/dev.c:6202
 __napi_poll+0xd3/0x610 net/core/dev.c:6853
 napi_poll net/core/dev.c:6922 [inline]
 net_rx_action+0x584/0xce0 net/core/dev.c:7044
 handle_softirqs+0x1ae/0x630 kernel/softirq.c:603
 __do_softirq+0xf/0x16 kernel/softirq.c:641
 do_softirq+0xa6/0x100 kernel/softirq.c:485
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:412
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_do_batch+0x5c6/0xd20 kernel/rcu/tree.c:2586
 nocb_cb_wait kernel/rcu/tree_nocb.h:923 [inline]
 rcu_nocb_cb_kthread+0x4dc/0xac0 kernel/rcu/tree_nocb.h:957
 kthread+0x2ca/0x370 kernel/kthread.c:389
 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
net_ratelimit: 126084 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e2:28:d4:89:ec:0f, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e2:28:d4:89:ec:0f, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e2:28:d4:89:ec:0f, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e2:28:d4:89:ec:0f, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e2:28:d4:89:ec:0f, vlan:0)

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/06/24 15:54 android16-6.12 9d80e3254812 e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2025/06/24 02:17 android16-6.12 1d4f4d446dbd e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2025/06/23 23:49 android16-6.12 1d4f4d446dbd e2f27c35 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2025/06/22 02:47 android16-6.12 d9fd901baa98 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2025/06/21 21:55 android16-6.12 d9fd901baa98 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2025/06/21 02:09 android16-6.12 d9fd901baa98 d6cdfb8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
* Struck through repros no longer work on HEAD.