INFO: task syz-executor2:18313 blocked for more than 140 seconds. Not tainted 4.18.0-rc8+ #181 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D25208 18313 4433 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_write_failed_common+0x95d/0x1630 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0xaa/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:715 [inline] vfs_setxattr+0x96/0x100 fs/xattr.c:219 setxattr+0x2ea/0x450 fs/xattr.c:451 path_setxattr+0x1e3/0x230 fs/xattr.c:470 __do_sys_setxattr fs/xattr.c:485 [inline] __se_sys_setxattr fs/xattr.c:481 [inline] __x64_sys_setxattr+0xc4/0x150 fs/xattr.c:481 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456d89 Code: 08 00 01 48 8b 3d 87 08 00 01 49 89 c8 48 29 d9 48 c1 e9 0d 48 39 f9 73 2e 48 8b 0c ce 48 85 c9 74 09 48 8b 59 18 49 39 d8 73 <05> 4c 89 c1 eb 90 48 8b 99 80 00 00 00 49 39 d8 73 ef 0f b6 49 64 RSP: 002b:00007efeea991c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc RAX: ffffffffffffffda RBX: 00007efeea9926d4 RCX: 0000000000456d89 RDX: 00000000200004c0 RSI: 00000000200005c0 RDI: 0000000020000680 RBP: 00000000009300a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000020 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d52f0 R14: 00000000004c30ee R15: 0000000000000000 INFO: task syz-executor2:18321 blocked for more than 140 seconds. Not tainted 4.18.0-rc8+ #181 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D22504 18321 4433 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 inode_lock_shared include/linux/fs.h:725 [inline] lookup_slow+0x49/0x80 fs/namei.c:1646 walk_component+0x94a/0x2630 fs/namei.c:1769 lookup_last fs/namei.c:2237 [inline] path_lookupat.isra.45+0x202/0xbf0 fs/namei.c:2287 filename_lookup+0x264/0x510 fs/namei.c:2321 kern_path+0x33/0x40 fs/namei.c:2410 unix_find_other+0xdd/0x5b0 net/unix/af_unix.c:905 unix_stream_connect+0x35e/0x11e0 net/unix/af_unix.c:1241 p9_fd_create_unix+0x258/0x370 net/9p/trans_fd.c:1009 p9_client_create+0x8ed/0x1770 net/9p/client.c:1063 v9fs_session_init+0x21a/0x1a80 fs/9p/v9fs.c:400 v9fs_mount+0x7c/0x900 fs/9p/vfs_super.c:135 mount_fs+0xae/0x328 fs/super.c:1277 vfs_kern_mount.part.34+0xdc/0x4e0 fs/namespace.c:1037 vfs_kern_mount fs/namespace.c:1027 [inline] do_new_mount fs/namespace.c:2518 [inline] do_mount+0x581/0x30e0 fs/namespace.c:2848 ksys_mount+0x12d/0x140 fs/namespace.c:3064 __do_sys_mount fs/namespace.c:3078 [inline] __se_sys_mount fs/namespace.c:3075 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3075 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456d89 Code: 08 00 01 48 8b 3d 87 08 00 01 49 89 c8 48 29 d9 48 c1 e9 0d 48 39 f9 73 2e 48 8b 0c ce 48 85 c9 74 09 48 8b 59 18 49 39 d8 73 <05> 4c 89 c1 eb 90 48 8b 99 80 00 00 00 49 39 d8 73 ef 0f b6 49 64 RSP: 002b:00007efeea94fc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007efeea9506d4 RCX: 0000000000456d89 RDX: 0000000020000500 RSI: 0000000020000380 RDI: 0000000020000140 RBP: 00000000009301e0 R08: 0000000020000640 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d1fd8 R14: 00000000004c76ed R15: 0000000000000002 INFO: task syz-executor2:18390 blocked for more than 140 seconds. Not tainted 4.18.0-rc8+ #181 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor2 D23096 18390 4433 0x00000004 Call Trace: context_switch kernel/sched/core.c:2853 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3501 schedule+0xfb/0x450 kernel/sched/core.c:3545 __rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:269 [inline] rwsem_down_read_failed+0x362/0x600 kernel/locking/rwsem-xadd.c:286 call_rwsem_down_read_failed+0x18/0x30 arch/x86/lib/rwsem.S:94 __down_read arch/x86/include/asm/rwsem.h:83 [inline] down_read+0xc3/0x1d0 kernel/locking/rwsem.c:26 inode_lock_shared include/linux/fs.h:725 [inline] lookup_slow+0x49/0x80 fs/namei.c:1646 walk_component+0x94a/0x2630 fs/namei.c:1769 lookup_last fs/namei.c:2237 [inline] path_lookupat.isra.45+0x202/0xbf0 fs/namei.c:2287 filename_lookup+0x264/0x510 fs/namei.c:2321 kern_path+0x33/0x40 fs/namei.c:2410 unix_find_other+0xdd/0x5b0 net/unix/af_unix.c:905 unix_stream_connect+0x35e/0x11e0 net/unix/af_unix.c:1241 p9_fd_create_unix+0x258/0x370 net/9p/trans_fd.c:1009 p9_client_create+0x8ed/0x1770 net/9p/client.c:1063 v9fs_session_init+0x21a/0x1a80 fs/9p/v9fs.c:400 v9fs_mount+0x7c/0x900 fs/9p/vfs_super.c:135 mount_fs+0xae/0x328 fs/super.c:1277 vfs_kern_mount.part.34+0xdc/0x4e0 fs/namespace.c:1037 vfs_kern_mount fs/namespace.c:1027 [inline] do_new_mount fs/namespace.c:2518 [inline] do_mount+0x581/0x30e0 fs/namespace.c:2848 ksys_mount+0x12d/0x140 fs/namespace.c:3064 __do_sys_mount fs/namespace.c:3078 [inline] __se_sys_mount fs/namespace.c:3075 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3075 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x456d89 Code: 08 00 01 48 8b 3d 87 08 00 01 49 89 c8 48 29 d9 48 c1 e9 0d 48 39 f9 73 2e 48 8b 0c ce 48 85 c9 74 09 48 8b 59 18 49 39 d8 73 <05> 4c 89 c1 eb 90 48 8b 99 80 00 00 00 49 39 d8 73 ef 0f b6 49 64 RSP: 002b:00007efeea92ec78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007efeea92f6d4 RCX: 0000000000456d89 RDX: 0000000020000500 RSI: 0000000020000380 RDI: 0000000020000140 RBP: 0000000000930280 R08: 0000000020000640 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d1fd8 R14: 00000000004c76ed R15: 0000000000000003 Showing all locks held in the system: 1 lock held by khungtaskd/773: #0: 000000003c6f8fe6 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 2 locks held by rs:main Q:Reg/4284: #0: 000000000ddd005f (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 #1: 0000000056952ffc (sb_writers#6){.+.+}, at: file_start_write include/linux/fs.h:2738 [inline] #1: 0000000056952ffc (sb_writers#6){.+.+}, at: vfs_write+0x452/0x560 fs/read_write.c:548 1 lock held by rsyslogd/4286: #0: 00000000f64a31a4 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4376: #0: 00000000676e13a9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000bbdedc73 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4377: #0: 00000000df5bea1b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000004086c82d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4378: #0: 000000005f95109e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000001d86b82f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4379: #0: 0000000039c221e5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000009e60788f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4380: #0: 000000005b9398c3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000001c1fc114 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4381: #0: 000000009d3c12e5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000f99a2baa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4382: #0: 0000000091771db9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000004d59e998 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor2/18313: #0: 000000003683a35c (sb_writers#19){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 000000003683a35c (sb_writers#19){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000854be2c8 (&sb->s_type->i_mutex_key#20){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 00000000854be2c8 (&sb->s_type->i_mutex_key#20){++++}, at: vfs_setxattr+0x96/0x100 fs/xattr.c:219 2 locks held by syz-executor2/18317: #0: 000000003683a35c (sb_writers#19){.+.+}, at: sb_start_write include/linux/fs.h:1554 [inline] #0: 000000003683a35c (sb_writers#19){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000854be2c8 (&sb->s_type->i_mutex_key#20){++++}, at: inode_lock include/linux/fs.h:715 [inline] #1: 00000000854be2c8 (&sb->s_type->i_mutex_key#20){++++}, at: vfs_setxattr+0x96/0x100 fs/xattr.c:219 1 lock held by syz-executor2/18321: #0: 00000000854be2c8 (&sb->s_type->i_mutex_key#20){++++}, at: inode_lock_shared include/linux/fs.h:725 [inline] #0: 00000000854be2c8 (&sb->s_type->i_mutex_key#20){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1646 1 lock held by syz-executor2/18390: #0: 00000000854be2c8 (&sb->s_type->i_mutex_key#20){++++}, at: inode_lock_shared include/linux/fs.h:725 [inline] #0: 00000000854be2c8 (&sb->s_type->i_mutex_key#20){++++}, at: lookup_slow+0x49/0x80 fs/namei.c:1646 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 773 Comm: khungtaskd Not tainted 4.18.0-rc8+ #181 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+0x1c9/0x2b4 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:138 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x345/0x410 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54