syzbot

INFO: task syz-executor5:15979 blocked for more than 140 seconds.
      Not tainted 4.19.0+ #85
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D23816 15979  15531 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2831 [inline]
 __schedule+0x8cf/0x21d0 kernel/sched/core.c:3480
 schedule+0xfe/0x460 kernel/sched/core.c:3524
 __rwsem_down_write_failed_common+0xc9a/0x15e0 kernel/locking/rwsem-xadd.c:577
 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606
 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+0xa5/0x130 kernel/locking/rwsem.c:72
 inode_lock include/linux/fs.h:757 [inline]
 vfs_setxattr+0x96/0x100 fs/xattr.c:218
 setxattr+0x2ea/0x450 fs/xattr.c:450
 path_setxattr+0x1e3/0x230 fs/xattr.c:469
 __do_sys_setxattr fs/xattr.c:484 [inline]
 __se_sys_setxattr fs/xattr.c:480 [inline]
 __x64_sys_setxattr+0xc4/0x150 fs/xattr.c:480
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d ca 96 0a <01> 87 01 8b 05 c2 96 0a 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00
RSP: 002b:00007f15c4c65c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457569
RDX: 0000000020005280 RSI: 0000000020005240 RDI: 0000000020005200
RBP: 000000000072bfa0 R08: 0000000000000001 R09: 0000000000000000
R10: 000000000000000e R11: 0000000000000246 R12: 00007f15c4c666d4
R13: 00000000004cb628 R14: 00000000004d7700 R15: 00000000ffffffff
INFO: task syz-executor5:15980 blocked for more than 140 seconds.
      Not tainted 4.19.0+ #85
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D23816 15980  15531 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2831 [inline]
 __schedule+0x8cf/0x21d0 kernel/sched/core.c:3480
 schedule+0xfe/0x460 kernel/sched/core.c:3524
 __rwsem_down_write_failed_common+0xc9a/0x15e0 kernel/locking/rwsem-xadd.c:577
 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606
 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+0xa5/0x130 kernel/locking/rwsem.c:72
 inode_lock include/linux/fs.h:757 [inline]
 lock_mount+0x8c/0x2e0 fs/namespace.c:2027
 do_add_mount+0x27/0x370 fs/namespace.c:2404
 do_new_mount fs/namespace.c:2471 [inline]
 do_mount+0x19cd/0x31f0 fs/namespace.c:2789
 ksys_mount+0x12d/0x140 fs/namespace.c:3005
 __do_sys_mount fs/namespace.c:3019 [inline]
 __se_sys_mount fs/namespace.c:3016 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3016
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d ca 96 0a <01> 87 01 8b 05 c2 96 0a 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00
RSP: 002b:00007f15c4c44c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457569
RDX: 00000000200008c0 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 000000000072c040 R08: 0000000020000a80 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f15c4c456d4
R13: 00000000004c2af8 R14: 00000000004d4160 R15: 00000000ffffffff
INFO: task syz-executor5:15981 blocked for more than 140 seconds.
      Not tainted 4.19.0+ #85
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D24648 15981  15531 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2831 [inline]
 __schedule+0x8cf/0x21d0 kernel/sched/core.c:3480
 schedule+0xfe/0x460 kernel/sched/core.c:3524
 __rwsem_down_write_failed_common+0xc9a/0x15e0 kernel/locking/rwsem-xadd.c:577
 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:606
 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+0xa5/0x130 kernel/locking/rwsem.c:72
 inode_lock include/linux/fs.h:757 [inline]
 do_last fs/namei.c:3321 [inline]
 path_openat+0x15c4/0x5150 fs/namei.c:3534
 do_filp_open+0x255/0x380 fs/namei.c:3564
 do_sys_open+0x568/0x700 fs/open.c:1063
 ksys_open include/linux/syscalls.h:1279 [inline]
 __do_sys_creat fs/open.c:1121 [inline]
 __se_sys_creat fs/open.c:1119 [inline]
 __x64_sys_creat+0x61/0x80 fs/open.c:1119
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: 83 c4 18 c3 e8 d8 64 00 00 48 8b 04 24 48 8b 4c 24 08 48 89 01 e8 d7 2d fc ff e8 22 7a fc ff b8 02 00 00 00 48 8d 0d ca 96 0a <01> 87 01 8b 05 c2 96 0a 01 83 f8 01 0f 85 8a 00 00 00 b8 01 00 00
RSP: 002b:00007f15c4c23c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000457569
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000300
RBP: 000000000072c0e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f15c4c246d4
R13: 00000000004bdb2f R14: 00000000004cc8e8 R15: 00000000ffffffff

Showing all locks held in the system:
1 lock held by khungtaskd/982:
 #0: 0000000046351213 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x424 kernel/locking/lockdep.c:4379
1 lock held by rsyslogd/5498:
 #0: 00000000eb7cb00b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766
2 locks held by getty/5589:
 #0: 00000000da5106b8 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 0000000048a13c3b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5590:
 #0: 000000009ef85b05 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 0000000068f68e1d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5591:
 #0: 000000007bc36e59 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000ea87f082 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5592:
 #0: 00000000bdb1c5cc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000c46c3ca3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5593:
 #0: 00000000387cba3e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000ec76f8bb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/5594:
 #0: 0000000050a81cc1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 000000009e308c41 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by syz-executor5/15931:
 #0: 00000000482fbee6 (sb_writers#23){.+.+}, at: sb_start_write include/linux/fs.h:1585 [inline]
 #0: 00000000482fbee6 (sb_writers#23){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
 #1: 00000000d40f831d (&sb->s_type->i_mutex_key#27){+.+.}, at: inode_lock include/linux/fs.h:757 [inline]
 #1: 00000000d40f831d (&sb->s_type->i_mutex_key#27){+.+.}, at: do_last fs/namei.c:3321 [inline]
 #1: 00000000d40f831d (&sb->s_type->i_mutex_key#27){+.+.}, at: path_openat+0x15c4/0x5150 fs/namei.c:3534
2 locks held by syz-executor5/15979:
 #0: 00000000482fbee6 (sb_writers#23){.+.+}, at: sb_start_write include/linux/fs.h:1585 [inline]
 #0: 00000000482fbee6 (sb_writers#23){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
 #1: 00000000d40f831d (&sb->s_type->i_mutex_key#27){+.+.}, at: inode_lock include/linux/fs.h:757 [inline]
 #1: 00000000d40f831d (&sb->s_type->i_mutex_key#27){+.+.}, at: vfs_setxattr+0x96/0x100 fs/xattr.c:218
1 lock held by syz-executor5/15980:
 #0: 00000000d40f831d (&sb->s_type->i_mutex_key#27){+.+.}, at: inode_lock include/linux/fs.h:757 [inline]
 #0: 00000000d40f831d (&sb->s_type->i_mutex_key#27){+.+.}, at: lock_mount+0x8c/0x2e0 fs/namespace.c:2027
2 locks held by syz-executor5/15981:
 #0: 00000000482fbee6 (sb_writers#23){.+.+}, at: sb_start_write include/linux/fs.h:1585 [inline]
 #0: 00000000482fbee6 (sb_writers#23){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
 #1: 00000000d40f831d (&sb->s_type->i_mutex_key#27){+.+.}, at: inode_lock include/linux/fs.h:757 [inline]
 #1: 00000000d40f831d (&sb->s_type->i_mutex_key#27){+.+.}, at: do_last fs/namei.c:3321 [inline]
 #1: 00000000d40f831d (&sb->s_type->i_mutex_key#27){+.+.}, at: path_openat+0x15c4/0x5150 fs/namei.c:3534
2 locks held by getty/15993:
 #0: 000000004d6df65a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:353
 #1: 00000000b474f2d5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 982 Comm: khungtaskd Not tainted 4.19.0+ #85
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+0x244/0x39d lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.1+0x5c/0xa1 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b3/0x1ed 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:144 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:204 [inline]
 watchdog+0xb3e/0x1050 kernel/hung_task.c:265
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:350
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:57