INFO: task syz-executor.4:10110 can't die for more than 143 seconds. task:syz-executor.4 state:D stack:27216 pid:10110 ppid: 8544 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8eb/0x21b0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 rwsem_down_write_slowpath+0x809/0x1220 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x132/0x150 kernel/locking/rwsem.c:1407 inode_lock include/linux/fs.h:773 [inline] lock_mount+0x8a/0x2e0 fs/namespace.c:2214 do_new_mount_fc fs/namespace.c:2842 [inline] do_new_mount fs/namespace.c:2901 [inline] path_mount+0x1678/0x1e70 fs/namespace.c:3230 do_mount fs/namespace.c:3243 [inline] __do_sys_mount fs/namespace.c:3451 [inline] __se_sys_mount fs/namespace.c:3428 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3428 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e149 RSP: 002b:00007f9e73cb4c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e149 RDX: 0000000020002000 RSI: 00000000200042c0 RDI: 0000000000000000 RBP: 000000000119bfd0 R08: 0000000020002140 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffdc93da1bf R14: 00007f9e73cb59c0 R15: 000000000119bf8c INFO: task syz-executor.4:10110 blocked for more than 143 seconds. Not tainted 5.10.0-next-20201223-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:27216 pid:10110 ppid: 8544 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4327 [inline] __schedule+0x8eb/0x21b0 kernel/sched/core.c:5078 schedule+0xcf/0x270 kernel/sched/core.c:5157 rwsem_down_write_slowpath+0x809/0x1220 kernel/locking/rwsem.c:1106 __down_write_common kernel/locking/rwsem.c:1261 [inline] __down_write_common kernel/locking/rwsem.c:1258 [inline] __down_write kernel/locking/rwsem.c:1270 [inline] down_write+0x132/0x150 kernel/locking/rwsem.c:1407 inode_lock include/linux/fs.h:773 [inline] lock_mount+0x8a/0x2e0 fs/namespace.c:2214 do_new_mount_fc fs/namespace.c:2842 [inline] do_new_mount fs/namespace.c:2901 [inline] path_mount+0x1678/0x1e70 fs/namespace.c:3230 do_mount fs/namespace.c:3243 [inline] __do_sys_mount fs/namespace.c:3451 [inline] __se_sys_mount fs/namespace.c:3428 [inline] __x64_sys_mount+0x27f/0x300 fs/namespace.c:3428 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e149 RSP: 002b:00007f9e73cb4c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045e149 RDX: 0000000020002000 RSI: 00000000200042c0 RDI: 0000000000000000 RBP: 000000000119bfd0 R08: 0000000020002140 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffdc93da1bf R14: 00007f9e73cb59c0 R15: 000000000119bf8c INFO: task syz-executor.4:10113 can't die for more than 144 seconds. task:syz-executor.4 state:R running task stack:27072 pid:10113 ppid: 8544 flags:0x00004006 Call Trace: Showing all locks held in the system: 1 lock held by khungtaskd/1625: #0: ffffffff8b793ae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x28c kernel/locking/lockdep.c:6254 1 lock held by in:imklog/8416: #0: ffff888020b67270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:949 1 lock held by syz-executor.4/10110: #0: ffff88807a553750 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: inode_lock include/linux/fs.h:773 [inline] #0: ffff88807a553750 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: lock_mount+0x8a/0x2e0 fs/namespace.c:2214 2 locks held by syz-executor.4/10113: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1625 Comm: khungtaskd Not tainted 5.10.0-next-20201223-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x3c/0xef lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xe75/0x1020 kernel/hung_task.c:338 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 8520 Comm: syz-fuzzer Not tainted 5.10.0-next-20201223-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:timerqueue_add+0xef/0x310 lib/timerqueue.c:40 Code: fd 4c 89 fa 48 c1 ea 03 42 80 3c 22 00 0f 85 b3 01 00 00 49 8b 17 48 85 d2 74 40 48 89 d3 e8 18 f0 96 fd 48 8d 7b 18 48 89 f8 <48> c1 e8 03 42 80 3c 20 00 0f 85 9a 01 00 00 4c 8b 7b 18 4c 89 ef RSP: 0018:ffffc9000175fbc0 EFLAGS: 00000093 RAX: ffff888014b12c18 RBX: ffff888014b12c00 RCX: 0000000000000000 RDX: ffff888011779b00 RSI: ffffffff83dc5af8 RDI: ffff888014b12c18 RBP: ffffc9000175fde8 R08: ffffc9000175fde8 R09: 0000000000000000 R10: ffffffff83dc5a54 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000007610eb21ad R14: 0000000000000001 R15: 0000000000000000 FS: 000000c00003e090(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000957000 CR3: 0000000025802000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: enqueue_hrtimer+0x176/0x400 kernel/time/hrtimer.c:971 __hrtimer_start_range_ns kernel/time/hrtimer.c:1102 [inline] hrtimer_start_range_ns+0x576/0x870 kernel/time/hrtimer.c:1132 hrtimer_start_expires include/linux/hrtimer.h:436 [inline] hrtimer_sleeper_start_expires kernel/time/hrtimer.c:1799 [inline] do_nanosleep+0x202/0x6a0 kernel/time/hrtimer.c:1875 hrtimer_nanosleep+0x1f9/0x430 kernel/time/hrtimer.c:1931 __do_sys_nanosleep kernel/time/hrtimer.c:1965 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:1952 [inline] __x64_sys_nanosleep+0x1dc/0x260 kernel/time/hrtimer.c:1952 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x468b3d Code: 8b 44 24 20 b9 40 42 0f 00 f7 f1 48 89 04 24 b8 e8 03 00 00 f7 e2 48 89 44 24 08 48 89 e7 be 00 00 00 00 b8 23 00 00 00 0f 05 <48> 8b 6c 24 10 48 83 c4 18 c3 cc cc cc cc cc cc cc cc cc b8 ba 00 RSP: 002b:000000c00004df18 EFLAGS: 00000202 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 0000000000000014 RCX: 0000000000468b3d RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000c00004df18 RBP: 000000c00004df28 R08: 000000761135803a R09: 00007fff22b16090 R10: 000000000001872e R11: 0000000000000202 R12: 0000000000439440 R13: 0000000000000009 R14: 000080c000346000 R15: 000080c00034dfff