INFO: task syz-executor.4:13809 can't die for more than 143 seconds. task:syz-executor.4 state:D stack:27280 pid:13809 ppid: 6576 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_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:00007fdff11a6188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056c0f0 RCX: 00000000004665f9 RDX: 0000000020000080 RSI: 0000000020000040 RDI: 0000000000000000 RBP: 00000000004bfcc4 R08: 0000000020000500 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0f0 R13: 00007ffe5f739cef R14: 00007fdff11a6300 R15: 0000000000022000 INFO: task syz-executor.4:13809 blocked for more than 143 seconds. Not tainted 5.14.0-next-20210910-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:27280 pid:13809 ppid: 6576 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_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:00007fdff11a6188 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 000000000056c0f0 RCX: 00000000004665f9 RDX: 0000000020000080 RSI: 0000000020000040 RDI: 0000000000000000 RBP: 00000000004bfcc4 R08: 0000000020000500 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c0f0 R13: 00007ffe5f739cef R14: 00007fdff11a6300 R15: 0000000000022000 Showing all locks held in the system: 2 locks held by kworker/0:1/7: #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: ffffc90000cc7db0 ((work_completion)(&m->wq)){+.+.}-{0:0}, at: process_one_work+0x8ca/0x1690 kernel/workqueue.c:2272 1 lock held by khungtaskd/27: #0: ffffffff8b97fce0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6446 1 lock held by in:imklog/6232: #0: ffff88801cd2d9f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.14.0-next-20210910-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: 10140 Comm: kworker/u4:7 Not tainted 5.14.0-next-20210910-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__this_cpu_preempt_check+0x1/0x20 lib/smp_processor_id.c:65 Code: be ff e8 f8 ed cc ff eb a2 0f 1f 44 00 00 48 c7 c6 00 32 e4 89 48 c7 c7 40 32 e4 89 e9 a8 fe ff ff 0f 1f 84 00 00 00 00 00 55 <48> 89 fd 0f 1f 44 00 00 48 89 ee 5d 48 c7 c7 80 32 e4 89 e9 87 fe RSP: 0018:ffffc90002f4fbb8 EFLAGS: 00000046 RAX: 0000000000000002 RBX: 3a8ff2597f922626 RCX: ffffc90002f4fc18 RDX: 1ffff1100f6c485e RSI: 0000000000000000 RDI: ffffffff898bfac0 RBP: 1ffff920005e9f7b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000003 R14: ffff88807b6242f8 R15: ffff88807b623900 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000603344 CR3: 0000000071de4000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:438 [inline] lock_release+0x3bb/0x720 kernel/locking/lockdep.c:5647 rcu_lock_release include/linux/rcupdate.h:272 [inline] rcu_read_unlock include/linux/rcupdate.h:720 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:414 [inline] batadv_nc_worker+0x86b/0xfa0 net/batman-adv/network-coding.c:721 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x3e5/0x4d0 kernel/kthread.c:319 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: e8 f8 ed cc ff callq 0xffccedfd 5: eb a2 jmp 0xffffffa9 7: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) c: 48 c7 c6 00 32 e4 89 mov $0xffffffff89e43200,%rsi 13: 48 c7 c7 40 32 e4 89 mov $0xffffffff89e43240,%rdi 1a: e9 a8 fe ff ff jmpq 0xfffffec7 1f: 0f 1f 84 00 00 00 00 nopl 0x0(%rax,%rax,1) 26: 00 27: 55 push %rbp * 28: 48 89 fd mov %rdi,%rbp <-- trapping instruction 2b: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 30: 48 89 ee mov %rbp,%rsi 33: 5d pop %rbp 34: 48 c7 c7 80 32 e4 89 mov $0xffffffff89e43280,%rdi 3b: e9 .byte 0xe9 3c: 87 fe xchg %edi,%esi