INFO: task syz-executor.0:11642 blocked for more than 143 seconds. Not tainted 5.16.0-rc1-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:26840 pid:11642 ppid: 6563 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 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: 0033:0x7f8025a0d8a7 RSP: 002b:00007f8022f82fa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000020000200 RCX: 00007f8025a0d8a7 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004 RBP: 00007f8022f836bc R08: 00007f8022f83040 R09: 0000000020000000 R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff R13: 0000000000000075 R14: 00007f8022f83000 R15: 0000000020000240 Showing all locks held in the system: 1 lock held by khungtaskd/27: #0: ffffffff8bb80fe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6238: #0: ffff88801d3553f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 2 locks held by systemd-udevd/11515: #0: ffff88801ad20118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 #1: ffff88801ad21360 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_open+0x75/0x120 drivers/block/loop.c:1733 1 lock held by syz-executor.0/11642: #0: ffff88801ad21360 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x7a/0x1070 drivers/block/loop.c:1106 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.16.0-rc1-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:210 [inline] watchdog+0xc1d/0xf50 kernel/hung_task.c:295 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: 2964 Comm: systemd-journal Not tainted 5.16.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:handle_mounts fs/namei.c:1480 [inline] RIP: 0010:step_into+0xa6/0x1c80 fs/namei.c:1800 Code: 00 00 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 45 c8 31 c0 e8 6c 6f ab ff 48 89 d8 48 c1 e8 03 42 80 3c 30 00 0f 85 fc 16 00 00 <48> 8b 03 4c 89 65 98 48 89 45 90 48 8d 43 38 48 89 c2 48 89 85 38 RSP: 0018:ffffc900027f7990 EFLAGS: 00000246 RAX: 1ffff920004fef9c RBX: ffffc900027f7ce0 RCX: 0000000000000000 RDX: ffff888011fae040 RSI: ffffffff81cb6224 RDI: ffffc900027f7ce0 RBP: ffffc900027f7a88 R08: 0000000000000002 R09: ffff88802058e4d8 R10: ffffffff81cb9502 R11: 0000000000000000 R12: ffff88802058e468 R13: ffff88807e49e3a0 R14: dffffc0000000000 R15: ffff888068654de5 FS: 00007fcfa4c208c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcfa2100020 CR3: 0000000024566000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: walk_component+0x171/0x6a0 fs/namei.c:1976 link_path_walk.part.0+0x757/0xd00 fs/namei.c:2297 link_path_walk fs/namei.c:2221 [inline] path_lookupat+0xc8/0x860 fs/namei.c:2448 filename_lookup+0x1c6/0x590 fs/namei.c:2478 user_path_at_empty+0x42/0x60 fs/namei.c:2801 user_path_at include/linux/namei.h:57 [inline] do_faccessat+0x127/0x850 fs/open.c:421 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: 0033:0x7fcfa3edb9c7 Code: 83 c4 08 48 3d 01 f0 ff ff 73 01 c3 48 8b 0d c8 d4 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 b8 15 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d a1 d4 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007ffce9a87098 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007ffce9a8a0c0 RCX: 00007fcfa3edb9c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000560a49e249a3 RBP: 00007ffce9a871e0 R08: 0000560a49e1a3e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000560a4be1b8c0 R15: 00007ffce9a876d0 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: f3 f3 65 48 8b 04 25 repz repz mov %gs:0x28,%rax 9: 28 00 00 00 d: 48 89 45 c8 mov %rax,-0x38(%rbp) 11: 31 c0 xor %eax,%eax 13: e8 6c 6f ab ff callq 0xffab6f84 18: 48 89 d8 mov %rbx,%rax 1b: 48 c1 e8 03 shr $0x3,%rax 1f: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) 24: 0f 85 fc 16 00 00 jne 0x1726 * 2a: 48 8b 03 mov (%rbx),%rax <-- trapping instruction 2d: 4c 89 65 98 mov %r12,-0x68(%rbp) 31: 48 89 45 90 mov %rax,-0x70(%rbp) 35: 48 8d 43 38 lea 0x38(%rbx),%rax 39: 48 89 c2 mov %rax,%rdx 3c: 48 rex.W 3d: 89 .byte 0x89 3e: 85 38 test %edi,(%rax)