INFO: task syz-executor.4:30117 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.4 state:D stack:27088 pid:30117 ppid: 16378 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xb72/0x1460 kernel/sched/core.c:6253 schedule+0x12b/0x1f0 kernel/sched/core.c:6326 blk_mq_freeze_queue_wait+0x105/0x190 block/blk-mq.c:178 del_gendisk+0x6d0/0x790 block/genhd.c:623 loop_remove drivers/block/loop.c:2080 [inline] loop_control_remove drivers/block/loop.c:2137 [inline] loop_control_ioctl+0x577/0x730 drivers/block/loop.c:2175 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl+0xfb/0x170 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f4a4e93eae9 RSP: 002b:00007f4a4beb4188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4a4ea51f60 RCX: 00007f4a4e93eae9 RDX: 0000000000000000 RSI: 0000000000004c81 RDI: 0000000000000003 RBP: 00007f4a4e998f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd4091fdbf R14: 00007f4a4beb4300 R15: 0000000000022000 Showing all locks held in the system: 6 locks held by kworker/u4:0/8: 1 lock held by khungtaskd/27: #0: ffffffff8cd1db00 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 1 lock held by in:imklog/6222: #0: ffff8880199cd4f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x24e/0x2f0 fs/file.c:990 2 locks held by agetty/6243: #0: ffff88801a8bf098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90001d482e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6c5/0x1c60 drivers/tty/n_tty.c:2113 ============================================= NMI backtrace for cpu 0 CPU: 0 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+0x1dc/0x2d8 lib/dump_stack.c:106 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x16a/0x280 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+0xc82/0xcd0 kernel/hung_task.c:295 kthread+0x468/0x490 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2957 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:__lock_acquire+0x1cc/0x2b00 kernel/locking/lockdep.c:4933 Code: b9 0a 76 0f 00 0f 84 c2 1a 00 00 8b 4d 20 48 c7 c0 00 db ae 8f 49 29 c6 49 c1 fe 06 48 ba ab aa aa aa aa aa aa aa 49 0f af d6 <41> 89 d6 85 db 4c 89 7c 24 28 48 89 9c 24 88 00 00 00 0f 84 45 01 RSP: 0018:ffffc90001d2f6c0 EFLAGS: 00000807 RAX: ffffffff8faedb00 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000028 RSI: dffffc0000000000 RDI: ffff88807b1c9d00 RBP: ffffc90001d2f810 R08: 0000000000000000 R09: 0000000000000000 R10: fffffbfff1c3d216 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000078 R15: ffff88807b1ca758 FS: 00007f384e3f98c0(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f384b3ad000 CR3: 000000001b8e5000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: lock_acquire+0x19f/0x4d0 kernel/locking/lockdep.c:5637 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:268 rcu_read_lock include/linux/rcupdate.h:688 [inline] mntput_no_expire+0xc3/0xfe0 fs/namespace.c:1163 path_put fs/namei.c:558 [inline] terminate_walk+0x1ee/0x570 fs/namei.c:672 path_parentat fs/namei.c:2504 [inline] filename_parentat+0x2be/0x7b0 fs/namei.c:2519 filename_create+0xf4/0x4e0 fs/namei.c:3637 do_mkdirat+0xae/0x530 fs/namei.c:3898 __do_sys_mkdir fs/namei.c:3929 [inline] __se_sys_mkdir fs/namei.c:3927 [inline] __x64_sys_mkdir+0x6a/0x80 fs/namei.c:3927 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f384d6b4687 Code: 00 b8 ff ff ff ff c3 0f 1f 40 00 48 8b 05 09 d8 2b 00 64 c7 00 5f 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 b8 53 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 d7 2b 00 f7 d8 64 89 01 48 RSP: 002b:00007fff9af8aeb8 EFLAGS: 00000293 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00007fff9af8ddd0 RCX: 00007f384d6b4687 RDX: 00007f384e125a00 RSI: 00000000000001ed RDI: 0000558832b9f8a0 RBP: 00007fff9af8aef0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fff9af8ddd0 R15: 00007fff9af8b3e0 ---------------- Code disassembly (best guess): 0: b9 0a 76 0f 00 mov $0xf760a,%ecx 5: 0f 84 c2 1a 00 00 je 0x1acd b: 8b 4d 20 mov 0x20(%rbp),%ecx e: 48 c7 c0 00 db ae 8f mov $0xffffffff8faedb00,%rax 15: 49 29 c6 sub %rax,%r14 18: 49 c1 fe 06 sar $0x6,%r14 1c: 48 ba ab aa aa aa aa movabs $0xaaaaaaaaaaaaaaab,%rdx 23: aa aa aa 26: 49 0f af d6 imul %r14,%rdx * 2a: 41 89 d6 mov %edx,%r14d <-- trapping instruction 2d: 85 db test %ebx,%ebx 2f: 4c 89 7c 24 28 mov %r15,0x28(%rsp) 34: 48 89 9c 24 88 00 00 mov %rbx,0x88(%rsp) 3b: 00 3c: 0f .byte 0xf 3d: 84 45 01 test %al,0x1(%rbp)