INFO: task syz-executor.3:15453 can't die for more than 143 seconds. task:syz-executor.3 state:D stack:27632 pid:15453 ppid: 6562 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4955 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6302 schedule+0xd3/0x270 kernel/sched/core.c:6381 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+0x56e/0xb10 kernel/workqueue.c:3083 __cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3170 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_init+0xfc0/0x17b0 fs/9p/v9fs.c:482 v9fs_mount+0x79/0x9c0 fs/9p/vfs_super.c:126 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:2988 [inline] path_mount+0x1320/0x1fa0 fs/namespace.c:3318 do_mount fs/namespace.c:3331 [inline] __do_sys_mount fs/namespace.c:3539 [inline] __se_sys_mount fs/namespace.c:3516 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3516 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: 0033:0x4665f9 RSP: 002b:00007f8c6b657188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665f9 RDX: 0000000020000100 RSI: 0000000020000040 RDI: 0000000000feffff RBP: 00000000004bfcc4 R08: 00000000200004c0 R09: 0000000000000000 R10: 000000000a004401 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffda73f6bef R14: 00007f8c6b657300 R15: 0000000000022000 INFO: task syz-executor.3:15453 blocked for more than 143 seconds. Not tainted 5.14.0-rc7-next-20210827-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:27632 pid:15453 ppid: 6562 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4955 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6302 schedule+0xd3/0x270 kernel/sched/core.c:6381 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+0x56e/0xb10 kernel/workqueue.c:3083 __cancel_work_timer+0x3f9/0x570 kernel/workqueue.c:3170 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_init+0xfc0/0x17b0 fs/9p/v9fs.c:482 v9fs_mount+0x79/0x9c0 fs/9p/vfs_super.c:126 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:2988 [inline] path_mount+0x1320/0x1fa0 fs/namespace.c:3318 do_mount fs/namespace.c:3331 [inline] __do_sys_mount fs/namespace.c:3539 [inline] __se_sys_mount fs/namespace.c:3516 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3516 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: 0033:0x4665f9 RSP: 002b:00007f8c6b657188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665f9 RDX: 0000000020000100 RSI: 0000000020000040 RDI: 0000000000feffff RBP: 00000000004bfcc4 R08: 00000000200004c0 R09: 0000000000000000 R10: 000000000a004401 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffda73f6bef R14: 00007f8c6b657300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8b97fbe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by in:imklog/6244: #0: ffff888072e42d70 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by kworker/0:12/12703: #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1198 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:634 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:661 [inline] #0: ffff888010c64d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x896/0x1690 kernel/workqueue.c:2268 #1: ffffc900050a7db0 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.14.0-rc7-next-20210827-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:106 nmi_cpu_backtrace.cold+0x47/0x144 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2960 Comm: systemd-journal Not tainted 5.14.0-rc7-next-20210827-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:preempt_count_sub+0x8/0x150 kernel/sched/core.c:5437 Code: 82 e8 1c 9c 6c 00 eb e4 48 89 df e8 12 9c 6c 00 eb 90 e8 0b 9c 6c 00 eb ac 66 0f 1f 84 00 00 00 00 00 48 c7 c0 e0 d8 24 90 53 <89> fb 48 ba 00 00 00 00 00 fc ff df 48 89 c1 83 e0 07 48 c1 e9 03 RSP: 0018:ffffc90002bbfa80 EFLAGS: 00000096 RAX: ffffffff9024d8e0 RBX: 0000000000031a80 RCX: ffffffff815bcf80 RDX: 1ffff11017386352 RSI: 0000000000000004 RDI: 0000000000000001 RBP: ffffc90002bbfb58 R08: 0000000000000001 R09: 0000000000000003 R10: fffff52000577f44 R11: 0000000000000000 R12: ffff8880b9c31a80 R13: ffff88807bc45580 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fee79ac28c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fee76f99028 CR3: 00000000245b2000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: raw_spin_rq_lock_nested kernel/sched/core.c:476 [inline] raw_spin_rq_lock kernel/sched/sched.h:1319 [inline] rq_lock kernel/sched/sched.h:1622 [inline] __schedule+0x240/0x26f0 kernel/sched/core.c:6216 schedule+0xd3/0x270 kernel/sched/core.c:6381 schedule_hrtimeout_range_clock+0x343/0x390 kernel/time/hrtimer.c:2296 ep_poll fs/eventpoll.c:1849 [inline] do_epoll_wait+0x1298/0x1940 fs/eventpoll.c:2227 __do_sys_epoll_wait fs/eventpoll.c:2239 [inline] __se_sys_epoll_wait fs/eventpoll.c:2234 [inline] __x64_sys_epoll_wait+0x158/0x270 fs/eventpoll.c:2234 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: 0033:0x7fee78d8b2e3 Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 83 3d 29 54 2b 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 0b c2 00 00 48 89 04 24 RSP: 002b:00007fff26168be8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 000055a9705311e0 RCX: 00007fee78d8b2e3 RDX: 0000000000000013 RSI: 00007fff26168bf0 RDI: 0000000000000008 RBP: 00007fff26168de0 R08: 00000000612a8367 R09: 00007fff261b4080 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fff26168bf0 R13: 0000000000000001 R14: ffffffffffffffff R15: 0005caa2f3997d8b ---------------- Code disassembly (best guess), 1 bytes skipped: 0: e8 1c 9c 6c 00 callq 0x6c9c21 5: eb e4 jmp 0xffffffeb 7: 48 89 df mov %rbx,%rdi a: e8 12 9c 6c 00 callq 0x6c9c21 f: eb 90 jmp 0xffffffa1 11: e8 0b 9c 6c 00 callq 0x6c9c21 16: eb ac jmp 0xffffffc4 18: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) 1f: 00 00 21: 48 c7 c0 e0 d8 24 90 mov $0xffffffff9024d8e0,%rax 28: 53 push %rbx * 29: 89 fb mov %edi,%ebx <-- trapping instruction 2b: 48 ba 00 00 00 00 00 movabs $0xdffffc0000000000,%rdx 32: fc ff df 35: 48 89 c1 mov %rax,%rcx 38: 83 e0 07 and $0x7,%eax 3b: 48 c1 e9 03 shr $0x3,%rcx