INFO: task syz-executor.3:12469 blocked for more than 140 seconds. Not tainted 4.19.161-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.3 D28984 12469 8160 0x00000004 Call Trace: context_switch kernel/sched/core.c:2828 [inline] __schedule+0x887/0x2040 kernel/sched/core.c:3517 schedule+0x8d/0x1b0 kernel/sched/core.c:3561 d_wait_lookup fs/dcache.c:2430 [inline] d_alloc_parallel+0x1292/0x19e0 fs/dcache.c:2512 __lookup_slow+0x18d/0x4a0 fs/namei.c:1655 lookup_slow fs/namei.c:1689 [inline] walk_component+0x7ac/0xda0 fs/namei.c:1811 lookup_last fs/namei.c:2274 [inline] path_lookupat+0x1ff/0x8d0 fs/namei.c:2319 filename_lookup+0x1ac/0x5a0 fs/namei.c:2349 user_path_at include/linux/namei.h:57 [inline] ksys_chdir+0x84/0x1d0 fs/open.c:458 __do_sys_chdir fs/open.c:480 [inline] __se_sys_chdir fs/open.c:478 [inline] __x64_sys_chdir+0x2d/0x40 fs/open.c:478 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45deb9 Code: f9 00 48 8d 15 08 b8 6c 01 48 89 14 24 e8 cf ce fa ff 0f b6 44 24 2f 3c 00 0f 85 10 01 00 00 e8 7d 7e fd ff 48 8d 05 cc c2 55 <00> 48 89 04 24 48 c7 44 24 08 11 00 00 00 e8 a4 87 fd ff 8b 44 24 RSP: 002b:00007f1ddec8ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000050 RAX: ffffffffffffffda RBX: 0000000000001e40 RCX: 000000000045deb9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000180 RBP: 000000000119c0a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c07c R13: 00007ffecc1297af R14: 00007f1ddec8b9c0 R15: 000000000119c07c Showing all locks held in the system: 1 lock held by khungtaskd/1567: #0: 00000000fb58dea6 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440 1 lock held by in:imklog/7856: #0: 00000000580886e5 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767 1 lock held by syz-executor.3/12469: #0: 00000000d464c636 (&sb->s_type->i_mutex_key#27){.+.+}, at: inode_lock_shared include/linux/fs.h:758 [inline] #0: 00000000d464c636 (&sb->s_type->i_mutex_key#27){.+.+}, at: lookup_slow fs/namei.c:1688 [inline] #0: 00000000d464c636 (&sb->s_type->i_mutex_key#27){.+.+}, at: walk_component+0x798/0xda0 fs/namei.c:1811 1 lock held by syz-executor.3/12480: #0: 00000000d464c636 (&sb->s_type->i_mutex_key#27){.+.+}, at: inode_lock_shared include/linux/fs.h:758 [inline] #0: 00000000d464c636 (&sb->s_type->i_mutex_key#27){.+.+}, at: lookup_slow fs/namei.c:1688 [inline] #0: 00000000d464c636 (&sb->s_type->i_mutex_key#27){.+.+}, at: walk_component+0x798/0xda0 fs/namei.c:1811 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1567 Comm: khungtaskd Not tainted 4.19.161-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1fc/0x2fe lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1a6/0x1eb lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0x991/0xe60 kernel/hung_task.c:287 kthread+0x33f/0x460 kernel/kthread.c:259 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4690 Comm: systemd-journal Not tainted 4.19.161-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0033:0x7fd31db6e3c2 Code: bb f2 ff 31 db e9 4b ff ff ff 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 83 fe 09 77 4b 48 8d 15 44 26 05 00 89 f6 48 63 04 b2 <48> 01 d0 ff e0 66 0f 1f 84 00 00 00 00 00 48 8b 47 10 c3 90 66 2e RSP: 002b:00007ffe7d408598 EFLAGS: 00000293 RAX: fffffffffffad9f0 RBX: 000055cc9d4451e0 RCX: 0000000000000000 RDX: 00007fd31dbc0a00 RSI: 0000000000000000 RDI: 000055cc9d445310 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000069 R11: 0000000000000206 R12: 00007ffe7d408650 R13: 0000000000001252 R14: 00007ffe7d40b440 R15: 00007ffe7d408a50 FS: 00007fd31de938c0 GS: 0000000000000000