INFO: task syz.2.1095:3555 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1095 state:D stack:0 pid:3555 tgid:3555 ppid:294 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 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:4657 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:12923 kvm_destroy_vm virt/kvm/kvm_main.c:1355 [inline] kvm_put_kvm+0xb04/0x12c0 virt/kvm/kvm_main.c:1392 kvm_vm_release+0x47/0x70 virt/kvm/kvm_main.c:1415 __fput+0x1fb/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e0/0x250 kernel/task_work.c:240 resume_user_mode_work+0x36/0x50 include/linux/resume_user_mode.h:50 exit_to_user_mode_loop kernel/entry/common.c:114 [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+0x64/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fc5a398efc9 RSP: 002b:00007ffe5effa2c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 000000000001d4cd RCX: 00007fc5a398efc9 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007fc5a3be7da0 R08: 0000000000000001 R09: 000000135effa5bf R10: 0000001b2df20000 R11: 0000000000000246 R12: 00007fc5a3be5fac R13: 00007fc5a3be5fa0 R14: ffffffffffffffff R15: 00007ffe5effa3e0 INFO: task syz.1.1105:3590 blocked for more than 126 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.1105 state:D stack:0 pid:3590 tgid:3589 ppid:289 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 schedule_preempt_disabled+0x14/0x30 kernel/sched/core.c:7944 __mutex_lock_common kernel/locking/mutex.c:707 [inline] __mutex_lock+0x81e/0x1b50 kernel/locking/mutex.c:803 __mutex_lock_slowpath+0xe/0x20 kernel/locking/mutex.c:1134 mutex_lock+0x102/0x1c0 kernel/locking/mutex.c:285 rcu_barrier+0x4d/0x530 kernel/rcu/tree.c:4589 flush_rcu_work+0x71/0x90 kernel/workqueue.c:4292 kvfree_rcu_barrier+0x18c/0x2f0 kernel/rcu/tree.c:3936 kmem_cache_destroy+0x32/0x170 mm/slab_common.c:490 p9_client_destroy+0x42b/0x480 net/9p/client.c:1088 v9fs_session_close+0x52/0x1d0 fs/9p/v9fs.c:506 v9fs_kill_super+0x60/0x90 fs/9p/vfs_super.c:196 deactivate_locked_super+0xd5/0x2a0 fs/super.c:476 v9fs_mount+0x764/0xa00 fs/9p/vfs_super.c:177 legacy_get_tree+0x106/0x1b0 fs/fs_context.c:662 vfs_get_tree+0x9e/0x290 fs/super.c:1817 do_new_mount+0x251/0xb40 fs/namespace.c:3537 path_mount+0x688/0x1050 fs/namespace.c:3864 do_mount fs/namespace.c:3877 [inline] __do_sys_mount fs/namespace.c:4087 [inline] __se_sys_mount+0x2bd/0x480 fs/namespace.c:4064 __x64_sys_mount+0xc3/0xf0 fs/namespace.c:4064 x64_sys_call+0x2021/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:166 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fef57b8efc9 RSP: 002b:00007fef58a81038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fef57de5fa0 RCX: 00007fef57b8efc9 RDX: 0000200000000080 RSI: 00002000000002c0 RDI: 0000000000000000 RBP: 00007fef57c11f91 R08: 0000200000001200 R09: 0000000000000000 R10: 0000000000000400 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fef57de6038 R14: 00007fef57de5fa0 R15: 00007fff73d5cd28 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: __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:267 [inline] watchdog+0xd8f/0xed0 kernel/hung_task.c:423 kthread+0x2ca/0x370 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 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 33 Comm: rcuop/1 Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:__sanitizer_cov_trace_switch+0xb/0x130 kernel/kcov.c:334 Code: 0a 20 5d e9 47 b7 09 04 cc 66 0f 1f 44 00 00 b8 7d 38 c7 01 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 06 48 8b 4e 08 <48> 83 c1 f8 48 c1 c1 3d 48 83 f9 02 7f 1e 48 85 c9 74 3c 48 83 f9 RSP: 0018:ffffc90000007308 EFLAGS: 00000202 RAX: 0000000000000002 RBX: ffffc900000073c8 RCX: 0000000000000008 RDX: 0000000000000100 RSI: ffffffff87b4ab60 RDI: 00000000000000e0 RBP: ffffc90000007330 R08: ffff888103678000 R09: 0000000000000003 R10: 0000000000000008 R11: 0000000000000100 R12: 00000000000002ff R13: dffffc0000000000 R14: 00000000000000e0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f076b61207e CR3: 000000010bb04000 CR4: 00000000003526b0 DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083 DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: ipv6_addr_type include/net/ipv6.h:546 [inline] rt6_need_strict include/net/ip6_route.h:66 [inline] ip6_route_input_lookup net/ipv6/route.c:2332 [inline] ip6_route_input+0x51a/0x8d0 net/ipv6/route.c:2631 ip6_rcv_finish_core net/ipv6/ip6_input.c:66 [inline] ip6_rcv_finish+0x15a/0x3e0 net/ipv6/ip6_input.c:77 NF_HOOK include/linux/netfilter.h:317 [inline] ipv6_rcv+0xed/0x220 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core net/core/dev.c:5769 [inline] __netif_receive_skb net/core/dev.c:5882 [inline] netif_receive_skb_internal net/core/dev.c:5968 [inline] netif_receive_skb+0x147/0x7b0 net/core/dev.c:6027 br_netif_receive_skb net/bridge/br_input.c:30 [inline] NF_HOOK include/linux/netfilter.h:317 [inline] br_pass_frame_up+0x126/0x1c0 net/bridge/br_input.c:70 br_handle_frame_finish+0x12d9/0x1720 net/bridge/br_input.c:221 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+0xf4b/0x3940 net/core/dev.c:5663 __netif_receive_skb_one_core net/core/dev.c:5767 [inline] __netif_receive_skb net/core/dev.c:5882 [inline] process_backlog+0x3e5/0xae0 net/core/dev.c:6218 __napi_poll+0xd3/0x610 net/core/dev.c:6869 napi_poll net/core/dev.c:6938 [inline] net_rx_action+0x584/0xce0 net/core/dev.c:7060 handle_softirqs+0x1ab/0x630 kernel/softirq.c:621 __do_softirq+0xf/0x16 kernel/softirq.c:659 do_softirq+0xa6/0x100 kernel/softirq.c:503 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_do_batch+0x5c6/0xd20 kernel/rcu/tree.c:2594 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+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244