INFO: task syz-executor.5:9778 can't die for more than 143 seconds. task:syz-executor.5 state:D stack:27512 pid: 9778 ppid: 9340 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4987 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6268 schedule+0xd2/0x260 kernel/sched/core.c:6341 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178 __loop_clr_fd+0x1ae/0x1070 drivers/block/loop.c:1122 loop_clr_fd drivers/block/loop.c:1237 [inline] lo_ioctl+0x398/0x17c0 drivers/block/loop.c:1562 blkdev_ioctl+0x37a/0x800 block/ioctl.c:609 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 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: 0033:0x7f0cda4cf8a7 RSP: 002b:00007f0cd7a44fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000020000080 RCX: 00007f0cda4cf8a7 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004 RBP: 00007f0cd7a456bc R08: 00007f0cd7a45040 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000005 R14: 00007f0cd7a45000 R15: 00000000200001c0 INFO: task syz-executor.5:9778 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-next-20211118-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.5 state:D stack:27512 pid: 9778 ppid: 9340 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4987 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6268 schedule+0xd2/0x260 kernel/sched/core.c:6341 blk_mq_freeze_queue_wait+0x112/0x160 block/blk-mq.c:178 __loop_clr_fd+0x1ae/0x1070 drivers/block/loop.c:1122 loop_clr_fd drivers/block/loop.c:1237 [inline] lo_ioctl+0x398/0x17c0 drivers/block/loop.c:1562 blkdev_ioctl+0x37a/0x800 block/ioctl.c:609 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 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: 0033:0x7f0cda4cf8a7 RSP: 002b:00007f0cd7a44fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000020000080 RCX: 00007f0cda4cf8a7 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004 RBP: 00007f0cd7a456bc R08: 00007f0cd7a45040 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000005 R14: 00007f0cd7a45000 R15: 00000000200001c0 Showing all locks held in the system: 1 lock held by khungtaskd/26: #0: ffffffff8bb83ba0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6434: #0: ffff88801c08d4f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by agetty/6442: #0: ffff88807f2f1098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffffc900029282e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113 2 locks held by systemd-udevd/9743: #0: ffff88801a11a918 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 #1: ffff88801a0fe360 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_open+0x75/0x120 drivers/block/loop.c:1733 1 lock held by syz-executor.5/9778: #0: ffff88801a0fe360 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x7a/0x1070 drivers/block/loop.c:1106 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 26 Comm: khungtaskd Not tainted 5.16.0-rc1-next-20211118-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:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 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+0x405/0x4f0 kernel/kthread.c:327 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: 29785 Comm: syz-executor.4 Not tainted 5.16.0-rc1-next-20211118-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:put_ucounts+0x7f/0x1c0 kernel/ucount.c:210 Code: 24 58 31 c0 e8 12 90 28 00 48 8d 7d 1c 48 c7 c6 40 50 a5 8b 48 8d 54 24 20 e8 8d 23 ab 02 31 ff 41 89 c4 89 c6 e8 11 92 28 00 <45> 85 e4 0f 84 cb 00 00 00 e8 e3 8f 28 00 48 8d 7d 08 48 89 f8 48 RSP: 0000:ffffc9001914fbd0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 1ffff92003229f7a RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff888146ef3a80 RDI: 0000000000000003 RBP: ffffffff8ba550a0 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff814f140f R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000090 R15: 0000000000000000 FS: 00007fee73764700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fee76195b11 CR3: 000000016104d000 CR4: 00000000003526f0 Call Trace: do_dec_rlimit_put_ucounts+0xe4/0x170 kernel/ucount.c:302 __sigqueue_free kernel/signal.c:455 [inline] __sigqueue_free kernel/signal.c:450 [inline] dequeue_synchronous_signal kernel/signal.c:748 [inline] get_signal+0x102a/0x28b0 kernel/signal.c:2715 arch_do_signal_or_restart+0x2a9/0x1c40 arch/x86/kernel/signal.c:868 handle_signal_work kernel/entry/common.c:148 [inline] exit_to_user_mode_loop kernel/entry/common.c:172 [inline] exit_to_user_mode_prepare+0x17d/0x290 kernel/entry/common.c:207 irqentry_exit_to_user_mode+0x5/0x40 kernel/entry/common.c:313 exc_page_fault+0xc6/0x180 arch/x86/mm/fault.c:1544 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568 RIP: 0033:0x7fee76195452 Code: ff e8 62 33 01 00 85 c0 0f 84 ba 01 00 00 64 f0 83 2c 25 b8 ff ff ff 01 e8 6b d1 00 00 48 8b 0c 24 8b 00 48 8b 99 80 00 00 00 <89> 81 88 00 00 00 85 c0 75 06 48 83 fb ff 74 18 48 63 44 24 14 48 RSP: 002b:00007fee737641a0 EFLAGS: 00010203 RAX: 0000000000000013 RBX: 00000002be5741c3 RCX: 00007fee76195a89 RDX: 00007fee7619542e RSI: 0000000000000001 RDI: 00007fee737645f0 RBP: 00007fee76248f6d R08: 00007fee737641a0 R09: 00007fee76248f6d R10: 00007ffeb79f3090 R11: 0000000000022f62 R12: 0000000000000000 R13: 00007ffeb79e508f R14: 00007fee73764300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 24 58 and $0x58,%al 2: 31 c0 xor %eax,%eax 4: e8 12 90 28 00 callq 0x28901b 9: 48 8d 7d 1c lea 0x1c(%rbp),%rdi d: 48 c7 c6 40 50 a5 8b mov $0xffffffff8ba55040,%rsi 14: 48 8d 54 24 20 lea 0x20(%rsp),%rdx 19: e8 8d 23 ab 02 callq 0x2ab23ab 1e: 31 ff xor %edi,%edi 20: 41 89 c4 mov %eax,%r12d 23: 89 c6 mov %eax,%esi 25: e8 11 92 28 00 callq 0x28923b * 2a: 45 85 e4 test %r12d,%r12d <-- trapping instruction 2d: 0f 84 cb 00 00 00 je 0xfe 33: e8 e3 8f 28 00 callq 0x28901b 38: 48 8d 7d 08 lea 0x8(%rbp),%rdi 3c: 48 89 f8 mov %rdi,%rax 3f: 48 rex.W