INFO: task syz-executor.3:27075 can't die for more than 143 seconds. task:syz-executor.3 state:D stack:27552 pid:27075 ppid: 6603 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4700 [inline] __schedule+0x949/0x2710 kernel/sched/core.c:5957 schedule+0xd3/0x290 kernel/sched/core.c:6036 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x176/0x280 kernel/sched/completion.c:138 __flush_work+0x50e/0xad0 kernel/workqueue.c:3053 __cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3140 p9_conn_destroy net/9p/trans_fd.c:891 [inline] p9_fd_close+0x305/0x520 net/9p/trans_fd.c:921 p9_client_destroy+0xbe/0x370 net/9p/client.c:1088 v9fs_session_close+0x45/0x2c0 fs/9p/v9fs.c:498 v9fs_kill_super+0x49/0x90 fs/9p/vfs_super.c:224 deactivate_locked_super+0x94/0x160 fs/super.c:335 v9fs_mount+0x7d0/0x9c0 fs/9p/vfs_super.c:205 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1498 do_new_mount fs/namespace.c:2978 [inline] path_mount+0x132a/0x1fa0 fs/namespace.c:3308 do_mount fs/namespace.c:3321 [inline] __do_sys_mount fs/namespace.c:3529 [inline] __se_sys_mount fs/namespace.c:3506 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3506 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 RSP: 002b:00007fc7bd4de188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056c0f0 RCX: 00000000004665e9 RDX: 0000000020000100 RSI: 0000000020000040 RDI: 0000000000feffff RBP: 00000000004bfcc4 R08: 0000000020000180 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0f0 R13: 00007ffdde65da0f R14: 00007fc7bd4de300 R15: 0000000000022000 INFO: task syz-executor.3:27075 blocked for more than 143 seconds. Not tainted 5.14.0-rc3-next-20210730-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:27552 pid:27075 ppid: 6603 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4700 [inline] __schedule+0x949/0x2710 kernel/sched/core.c:5957 schedule+0xd3/0x290 kernel/sched/core.c:6036 schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857 do_wait_for_common kernel/sched/completion.c:85 [inline] __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x176/0x280 kernel/sched/completion.c:138 __flush_work+0x50e/0xad0 kernel/workqueue.c:3053 __cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3140 p9_conn_destroy net/9p/trans_fd.c:891 [inline] p9_fd_close+0x305/0x520 net/9p/trans_fd.c:921 p9_client_destroy+0xbe/0x370 net/9p/client.c:1088 v9fs_session_close+0x45/0x2c0 fs/9p/v9fs.c:498 v9fs_kill_super+0x49/0x90 fs/9p/vfs_super.c:224 deactivate_locked_super+0x94/0x160 fs/super.c:335 v9fs_mount+0x7d0/0x9c0 fs/9p/vfs_super.c:205 legacy_get_tree+0x105/0x220 fs/fs_context.c:610 vfs_get_tree+0x89/0x2f0 fs/super.c:1498 do_new_mount fs/namespace.c:2978 [inline] path_mount+0x132a/0x1fa0 fs/namespace.c:3308 do_mount fs/namespace.c:3321 [inline] __do_sys_mount fs/namespace.c:3529 [inline] __se_sys_mount fs/namespace.c:3506 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3506 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665e9 RSP: 002b:00007fc7bd4de188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056c0f0 RCX: 00000000004665e9 RDX: 0000000020000100 RSI: 0000000020000040 RDI: 0000000000feffff RBP: 00000000004bfcc4 R08: 0000000020000180 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0f0 R13: 00007ffdde65da0f R14: 00007fc7bd4de300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/26: #0: ffffffff8b97e980 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by in:imklog/6264: #0: ffff888025db59f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by kworker/1:6/8495: #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:617 [inline] #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline] #0: ffff888010864d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x871/0x1630 kernel/workqueue.c:2247 #1: ffffc900171f7db0 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x8a5/0x1630 kernel/workqueue.c:2251 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.14.0-rc3-next-20210730-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:105 nmi_cpu_backtrace.cold+0x28/0x11b lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:254 [inline] watchdog+0xcb7/0xed0 kernel/hung_task.c:339 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 26810 Comm: kworker/1:0 Not tainted 5.14.0-rc3-next-20210730-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events nsim_dev_trap_report_work RIP: 0010:next_tid mm/slub.c:2169 [inline] RIP: 0010:___slab_alloc+0x110/0x820 mm/slub.c:2791 Code: 9a 00 00 00 48 8b 85 78 ff ff ff 4c 8b 70 10 41 80 7e 2b 00 0f 89 9d 05 00 00 41 8b 44 24 28 48 8b b5 78 ff ff ff 49 8b 04 07 <48> 83 46 08 08 48 89 06 48 8b 45 c8 65 48 2b 04 25 28 00 00 00 0f RSP: 0018:ffffc9000510fab0 EFLAGS: 00000082 RAX: ffff88807cae5c80 RBX: 0000000000000002 RCX: 0000000000000000 RDX: ffff88807cae5dc0 RSI: ffff8880b9d39800 RDI: 0000000000000001 RBP: ffffc9000510fb70 R08: 0000000000000000 R09: ffff888015be0303 R10: ffffed1002b7c060 R11: 0000000000086088 R12: ffff888015bdb000 R13: 0000000000000a20 R14: ffffea0001f2b940 R15: ffff88807cae5dc0 FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd195084000 CR3: 000000002698b000 CR4: 00000000001526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2843 slab_alloc_node mm/slub.c:2925 [inline] kmem_cache_alloc_node+0x12c/0x3e0 mm/slub.c:2995 __alloc_skb+0x20b/0x340 net/core/skbuff.c:414 alloc_skb include/linux/skbuff.h:1116 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:664 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:721 [inline] nsim_dev_trap_report_work+0x2ac/0xbd0 drivers/net/netdevsim/dev.c:762 process_one_work+0x98d/0x1630 kernel/workqueue.c:2276 worker_thread+0x658/0x11f0 kernel/workqueue.c:2422 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295