syzbot


INFO: task hung in kvm_mmu_uninit_tdp_mmu (2)

Status: premoderation: reported on 2026/01/24 19:57
Reported-by: syzbot+aebf766ff4e64a1b32c9@syzkaller.appspotmail.com
First crash: 156d, last: 3d05h
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-12 INFO: task hung in kvm_mmu_uninit_tdp_mmu 1 115 229d 374d 0/1 auto-obsoleted due to no activity on 2026/01/01 13:24

Sample crash report:
INFO: task syz.5.997:3663 blocked for more than 123 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.5.997       state:D stack:0     pid:3663  tgid:3663  ppid:2337   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:6052 [inline]
 __schedule+0x1496/0x20b0 kernel/sched/core.c:7865
 __schedule_loop kernel/sched/core.c:7942 [inline]
 schedule+0xc5/0x240 kernel/sched/core.c:7957
 schedule_timeout+0xc7/0x3b0 kernel/time/timer.c:2596
 do_wait_for_common kernel/sched/completion.c:95 [inline]
 __wait_for_common kernel/sched/completion.c:116 [inline]
 wait_for_common+0x368/0x650 kernel/sched/completion.c:127
 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148
 rcu_barrier+0x45a/0x580 kernel/rcu/tree.c:4657
 kvm_mmu_uninit_tdp_mmu+0x1ea/0x210 arch/x86/kvm/mmu/tdp_mmu.c:51
 kvm_mmu_uninit_vm+0x27/0x60 arch/x86/kvm/mmu/mmu.c:6569
 kvm_arch_destroy_vm+0x395/0x410 arch/x86/kvm/x86.c:13008
 kvm_destroy_vm virt/kvm/kvm_main.c:1355 [inline]
 kvm_put_kvm+0xadf/0x12d0 virt/kvm/kvm_main.c:1392
 kvm_vm_release+0x47/0x70 virt/kvm/kvm_main.c:1415
 __fput+0x208/0xa30 fs/file_table.c:447
 ____fput+0x20/0x30 fs/file_table.c:475
 task_work_run+0x1e8/0x260 kernel/task_work.c:246
 exit_task_work include/linux/task_work.h:43 [inline]
 do_exit+0xa46/0x2850 kernel/exit.c:955
 do_group_exit+0x21f/0x2f0 kernel/exit.c:1098
 get_signal+0x134c/0x1490 kernel/signal.c:2933
 arch_do_signal_or_restart+0xbc/0x700 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+0x57/0xb0 kernel/entry/common.c:218
 do_syscall_64+0x63/0xf0 arch/x86/entry/common.c:84
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f428b15d68e
RSP: 002b:00007f428c038f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007f428c0396c0 RCX: 00007f428b15d68e
RDX: 00007f428c038fb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f428b232e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f428b416218 R14: 00007f428b416180 R15: 00007ffea6d66de8
 </TASK>
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 e549a79720f8b9d2445064a5e8a439d230f1aa2c
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x30 lib/dump_stack.c:94
 dump_stack_lvl+0x140/0x1c0 lib/dump_stack.c:120
 dump_stack+0x19/0x20 lib/dump_stack.c:129
 nmi_cpu_backtrace+0x2ba/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:267 [inline]
 watchdog+0xe45/0xf90 kernel/hung_task.c:423
 kthread+0x2c7/0x360 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 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: 30 Comm: ksoftirqd/1 Not tainted syzkaller #0 e549a79720f8b9d2445064a5e8a439d230f1aa2c
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:update_stack_state+0x38c/0x4d0 arch/x86/kernel/unwind_frame.c:244
Code: 42 80 3c 38 00 74 08 4c 89 f7 e8 5f 89 9b 00 48 8b 45 98 49 89 06 49 89 c6 48 8b 45 a0 42 80 3c 38 00 48 8b 45 d0 4c 8d 60 58 <74> 08 4c 89 e7 e8 3a 89 9b 00 49 c7 04 24 00 00 00 00 49 83 c6 08
RSP: 0018:ffffc900001f6ec8 EFLAGS: 00000246
RAX: ffffc900001f6fe8 RBX: ffffc900001f6ff0 RCX: ffffc900001f7f01
RDX: ffffc900001f7f18 RSI: 1ffff9200003edfe RDI: 0000000000000000
RBP: ffffc900001f6f78 R08: ffffc900001f70b0 R09: ffffc900001f70a8
R10: 0000000000000010 R11: ffffffff81759b00 R12: ffffc900001f7040
R13: 1ffff9200003ee05 R14: ffffc900001f7f18 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f2b53747e20 CR3: 00000000074aa000 CR4: 00000000003526b0
Call Trace:
 <TASK>
 unwind_next_frame+0x39e/0x6b0 arch/x86/kernel/unwind_frame.c:315
 arch_stack_walk+0x138/0x170 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:49 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:70
 kasan_save_alloc_info+0x3a/0x50 mm/kasan/generic.c:565
 unpoison_slab_object mm/kasan/common.c:321 [inline]
 __kasan_slab_alloc+0x73/0x90 mm/kasan/common.c:347
 kasan_slab_alloc include/linux/kasan.h:251 [inline]
 slab_post_alloc_hook mm/slub.c:4202 [inline]
 slab_alloc_node mm/slub.c:4251 [inline]
 kmem_cache_alloc_node_noprof+0x1ca/0x420 mm/slub.c:4305
 __alloc_skb+0x10c/0x360 net/core/skbuff.c:677
 alloc_skb include/linux/skbuff.h:1363 [inline]
 nlmsg_new include/net/netlink.h:1015 [inline]
 fdb_notify+0x78/0x150 net/bridge/br_fdb.c:195
 br_fdb_update+0x5b7/0x6c0 net/bridge/br_fdb.c:951
 br_handle_frame_finish+0x385/0x1620 net/bridge/br_input.c:141
 nf_hook_bridge_pre net/bridge/br_input.c:301 [inline]
 br_handle_frame+0x5a5/0xba0 net/bridge/br_input.c:424
 __netif_receive_skb_core+0xfc4/0x3a70 net/core/dev.c:5695
 __netif_receive_skb_one_core net/core/dev.c:5799 [inline]
 __netif_receive_skb net/core/dev.c:5914 [inline]
 process_backlog+0x40b/0xaf0 net/core/dev.c:6250
 __napi_poll+0xd0/0x600 net/core/dev.c:6901
 napi_poll net/core/dev.c:6970 [inline]
 net_rx_action+0x5dc/0xd70 net/core/dev.c:7092
 handle_softirqs+0x1aa/0x620 kernel/softirq.c:621
 run_ksoftirqd+0x20/0x30 kernel/softirq.c:999
 smpboot_thread_fn+0x483/0x8b0 kernel/smpboot.c:164
 kthread+0x2c7/0x360 kernel/kthread.c:389
 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
net_ratelimit: 120237 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 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:f2:04:d9:6d:c1:00, 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:aa:aa:aa:aa:aa:0c, 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, 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:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
net_ratelimit: 132327 callbacks suppressed
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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, 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 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:f2:04:d9:6d:c1:00, 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:aa:aa:aa:aa:aa:0c, 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 bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)

Crashes (104):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/26 22:57 android16-6.12 220923cf9f76 fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/26 07:58 android16-6.12 cc87569b5721 7ff32d8b .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/24 06:54 android16-6.12 24621bda288e 042555ff .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/23 16:42 android16-6.12 8f68185b8289 4b1d8f01 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/22 03:32 android16-6.12 8f68185b8289 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/20 08:39 android16-6.12 8f68185b8289 43bfcdb0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/19 18:40 android16-6.12 8f68185b8289 570c59ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/18 17:14 android16-6.12 8f68185b8289 a776b0d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/18 15:08 android16-6.12 8f68185b8289 a776b0d0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/17 17:06 android16-6.12 8f68185b8289 b62b3ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/17 05:18 android16-6.12 8f68185b8289 62cc6db3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/16 23:26 android16-6.12 8f68185b8289 62cc6db3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/15 05:33 android16-6.12 8f68185b8289 1d2f3589 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/10 10:33 android16-6.12 cf3d484a7cc5 34dab4be .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/07 17:39 android16-6.12 468e09dd6f52 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/07 13:53 android16-6.12 468e09dd6f52 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/07 04:44 android16-6.12 468e09dd6f52 cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/04 10:03 android16-6.12 8b70dc440368 197909be .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/03 01:59 android16-6.12 66b8d2a9700a 3c0d2131 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/02 21:43 android16-6.12 215bb7dbd9d4 62fe1528 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/06/01 06:46 android16-6.12 34c0581154b9 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/30 11:15 android16-6.12 34c0581154b9 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/29 13:09 android16-6.12 d398eeb1f23e 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/27 01:32 android16-6.12 ad34d1539656 2b01f00e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/26 02:01 android16-6.12 28ab3740535f c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/24 02:17 android16-6.12 28ab3740535f c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/20 23:13 android16-6.12 f0dd0605ee81 62fb93a2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/20 14:24 android16-6.12 0819c4ac7768 62fb93a2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/19 11:12 android16-6.12 be343ff665e2 223544dc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/18 16:47 android16-6.12 be343ff665e2 55156e84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/14 19:46 android16-6.12 20cf7b36edc7 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/14 11:27 android16-6.12 098cf2128230 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/13 20:46 android16-6.12 de7da43e33fd fec2a7ee .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/10 06:01 android16-6.12 5efa9ec22e39 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/10 02:54 android16-6.12 5efa9ec22e39 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/09 17:02 android16-6.12 5efa9ec22e39 29233ece .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/08 16:28 android16-6.12 6302a0abb9ea b2988c17 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/07 20:29 android16-6.12 ca96d08337a8 cbf9e0fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/07 14:44 android16-6.12 ca96d08337a8 cbf9e0fc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/07 10:34 android16-6.12 f0eb259b5af5 f250db59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/06 09:31 android16-6.12 59a61a07862b 26da2c66 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/04 07:01 android16-6.12 8ed163f1fc8c a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/04 04:38 android16-6.12 8ed163f1fc8c a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/05/02 05:44 android16-6.12 8ed163f1fc8c 753c55b9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/04/29 04:47 android16-6.12 c96ce3cae8c3 95008c03 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-12-rust INFO: task hung in kvm_mmu_uninit_tdp_mmu
2026/04/28 05:13 android16-6.12 18d3876842e1 ce741359 .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.