INFO: task syz-executor.0:27209 can't die for more than 143 seconds. task:syz-executor.0 state:D stack:29072 pid:27209 ppid: 21913 flags:0x00004004 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: 0033:0x7f6865788ae9 RSP: 002b:00007f6862cbc188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f686589c0e0 RCX: 00007f6865788ae9 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004 RBP: 00007f68657e2f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffb0b4b25f R14: 00007f6862cbc300 R15: 0000000000022000 INFO: task syz-executor.0:27209 blocked for more than 143 seconds. Not tainted 5.15.0-next-20211115-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:29072 pid:27209 ppid: 21913 flags:0x00004004 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: 0033:0x7f6865788ae9 RSP: 002b:00007f6862cbc188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f686589c0e0 RCX: 00007f6865788ae9 RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000004 RBP: 00007f68657e2f6d R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffb0b4b25f R14: 00007f6862cbc300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by khungtaskd/26: #0: ffffffff8bb83aa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6458 1 lock held by in:imklog/6387: #0: ffff8880733020f0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:990 3 locks held by kworker/u4:7/14256: 2 locks held by agetty/24581: #0: ffff888073bbc098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:252 #1: ffffc900050eb2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2113 2 locks held by systemd-udevd/26988: #0: ffff88801a814118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xb50 block/bdev.c:819 #1: ffff888147228360 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_open+0x75/0x120 drivers/block/loop.c:1733 1 lock held by syz-executor.0/27209: #0: ffff888147228360 (&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 5.15.0-next-20211115-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: 2959 Comm: systemd-journal Not tainted 5.15.0-next-20211115-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:hash_name fs/namei.c:2154 [inline] RIP: 0010:link_path_walk.part.0+0x387/0xd00 fs/namei.c:2243 Code: e8 7e a1 aa ff 4d 85 e4 74 83 4c 89 6c 24 18 4d 89 f5 4c 8b 74 24 20 e8 d7 9e aa ff 49 8d 4c 24 ff 4c 89 e2 4c 89 e8 48 f7 d2 <4c> 8b 6c 24 18 48 be 00 00 00 00 00 fc ff df 48 21 ca 48 b9 08 06 RSP: 0018:ffffc9000205fb58 EFLAGS: 00000293 RAX: 2f6c616e72756f6a RBX: ffff888011241490 RCX: 7fffffffffffffff RDX: 7fffffffffffffff RSI: ffffffff81cd5049 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81cd5032 R11: 0000000000000000 R12: 8000000000000000 R13: 2f6c616e72756f6a R14: ffffc9000205fce0 R15: ffff88804791c42d FS: 00007f8032a248c0(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f80300b1000 CR3: 000000001c195000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: 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: 0033:0x7f8031cdf9c7 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:00007fff604c5b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000015 RAX: ffffffffffffffda RBX: 00007fff604c8b50 RCX: 00007f8031cdf9c7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00005634d00549a3 RBP: 00007fff604c5c70 R08: 00005634d004a3e5 R09: 0000000000000018 R10: 0000000000000069 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00005634d1f4d8a0 R15: 00007fff604c6160 ---------------- Code disassembly (best guess): 0: e8 7e a1 aa ff callq 0xffaaa183 5: 4d 85 e4 test %r12,%r12 8: 74 83 je 0xffffff8d a: 4c 89 6c 24 18 mov %r13,0x18(%rsp) f: 4d 89 f5 mov %r14,%r13 12: 4c 8b 74 24 20 mov 0x20(%rsp),%r14 17: e8 d7 9e aa ff callq 0xffaa9ef3 1c: 49 8d 4c 24 ff lea -0x1(%r12),%rcx 21: 4c 89 e2 mov %r12,%rdx 24: 4c 89 e8 mov %r13,%rax 27: 48 f7 d2 not %rdx * 2a: 4c 8b 6c 24 18 mov 0x18(%rsp),%r13 <-- trapping instruction 2f: 48 be 00 00 00 00 00 movabs $0xdffffc0000000000,%rsi 36: fc ff df 39: 48 21 ca and %rcx,%rdx 3c: 48 rex.W 3d: b9 .byte 0xb9 3e: 08 06 or %al,(%rsi)