INFO: task syz-executor.2:13321 can't die for more than 143 seconds. task:syz-executor.2 state:D stack:28120 pid:13321 ppid: 6564 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4955 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6236 schedule+0xd3/0x270 kernel/sched/core.c:6315 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_create+0x95a/0x1110 net/9p/client.c:1073 v9fs_session_init+0x1dd/0x17b0 fs/9p/v9fs.c:406 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:00007fc54eb57188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665f9 RDX: 0000000020000100 RSI: 0000000020000040 RDI: 0000000000feffff RBP: 00000000004bfcc4 R08: 0000000020000240 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffd8e9b681f R14: 00007fc54eb57300 R15: 0000000000022000 INFO: task syz-executor.2:13321 blocked for more than 143 seconds. Not tainted 5.15.0-rc1-next-20210915-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:28120 pid:13321 ppid: 6564 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4955 [inline] __schedule+0x940/0x26f0 kernel/sched/core.c:6236 schedule+0xd3/0x270 kernel/sched/core.c:6315 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_create+0x95a/0x1110 net/9p/client.c:1073 v9fs_session_init+0x1dd/0x17b0 fs/9p/v9fs.c:406 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:00007fc54eb57188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665f9 RDX: 0000000020000100 RSI: 0000000020000040 RDI: 0000000000feffff RBP: 00000000004bfcc4 R08: 0000000020000240 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038 R13: 00007ffd8e9b681f R14: 00007fc54eb57300 R15: 0000000000022000 Showing all locks held in the system: 2 locks held by kworker/0:0/5: #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: ffffc90000ca7db0 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272 1 lock held by khungtaskd/26: #0: ffffffff8b97ffa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 3 locks held by kworker/u4:2/148: 1 lock held by in:imklog/6230: #0: ffff88801d0ff270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 26 Comm: khungtaskd Not tainted 5.15.0-rc1-next-20210915-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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2952 Comm: systemd-journal Not tainted 5.15.0-rc1-next-20210915-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:devkmsg_read+0x325/0x730 kernel/printk/printk.c:745 Code: 8b 74 24 10 48 c7 c7 40 f3 96 8b e8 65 48 fa ff e8 10 8f 18 00 4c 89 fa 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 4f 03 00 00 48 8b 9d 50 41 00 00 48 b8 00 00 00 00 00 fc ff RSP: 0018:ffffc90002acfd60 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffff88807c590c80 RCX: 0000000000000000 RDX: 1ffff1100f73782a RSI: ffffffff815d86d0 RDI: 0000000000000003 RBP: ffff88807b9b8000 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff815d8531 R11: 0000000000000000 R12: 1ffff92000559fb1 R13: 0000000000000001 R14: ffff88807b9b8068 R15: ffff88807b9bc150 FS: 00007f96943f78c0(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f969189d008 CR3: 000000001d96e000 CR4: 00000000001506e0 Call Trace: vfs_read+0x1b5/0x600 fs/read_write.c:483 ksys_read+0x12d/0x250 fs/read_write.c:623 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: 0033:0x7f9693986210 Code: 73 01 c3 48 8b 0d 98 7d 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d b9 c1 20 00 00 75 10 b8 00 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 4e fc ff ff 48 89 04 24 RSP: 002b:00007ffe542db828 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00007ffe542de2a0 RCX: 00007f9693986210 RDX: 0000000000002000 RSI: 00007ffe542dc0a0 RDI: 0000000000000009 RBP: 0000000000000000 R08: 0000000000000008 R09: 00007ffe543b2080 R10: 00007ffe543b20f0 R11: 0000000000000246 R12: 00007ffe542dc0a0 R13: 00007ffe542de1f8 R14: 00005640b6901958 R15: 0005cc032bda0a88 ---------------- Code disassembly (best guess): 0: 8b 74 24 10 mov 0x10(%rsp),%esi 4: 48 c7 c7 40 f3 96 8b mov $0xffffffff8b96f340,%rdi b: e8 65 48 fa ff callq 0xfffa4875 10: e8 10 8f 18 00 callq 0x188f25 15: 4c 89 fa mov %r15,%rdx 18: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 1f: fc ff df 22: 48 c1 ea 03 shr $0x3,%rdx 26: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) * 2a: 0f 85 4f 03 00 00 jne 0x37f <-- trapping instruction 30: 48 8b 9d 50 41 00 00 mov 0x4150(%rbp),%rbx 37: 48 rex.W 38: b8 00 00 00 00 mov $0x0,%eax 3d: 00 fc add %bh,%ah 3f: ff .byte 0xff