syzbot


INFO: task hung in lock_mount

Status: auto-closed as invalid on 2020/05/09 01:51
Reported-by: syzbot+51860817423898027428@syzkaller.appspotmail.com
First crash: 1746d, last: 1616d
Similar bugs (8)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 INFO: task hung in lock_mount (4) 6 941d 1055d 0/1 auto-closed as invalid on 2022/03/15 09:18
android-49 INFO: task hung in lock_mount C 103 1772d 1890d 0/3 public: reported C repro on 2019/04/11 08:44
linux-5.15 INFO: task hung in lock_mount origin:upstream C error 1 49d 49d 0/3 upstream: reported C repro on 2024/04/25 09:15
upstream INFO: task hung in lock_mount nilfs C error error 1238 421d 2235d 22/28 fixed on 2023/06/08 14:41
linux-4.19 INFO: task hung in lock_mount (2) 2 1453d 1459d 0/1 auto-closed as invalid on 2020/10/18 21:28
android-44 INFO: task hung in lock_mount C 4 2170d 1888d 0/2 public: reported C repro on 2019/04/13 00:00
linux-4.19 INFO: task hung in lock_mount (3) 1 1219d 1219d 0/1 auto-closed as invalid on 2021/06/09 16:09
linux-4.14 INFO: task hung in lock_mount 2 1648d 1649d 0/1 auto-closed as invalid on 2020/04/07 06:26

Sample crash report:
INFO: task syz-executor.5:26127 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D27768 26127   8136 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
 rwsem_down_write_failed+0x774/0xc30 kernel/locking/rwsem-xadd.c:618
 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+0x53/0x90 kernel/locking/rwsem.c:72
 inode_lock include/linux/fs.h:747 [inline]
 lock_mount+0x8c/0x2e0 fs/namespace.c:2039
 do_add_mount+0x27/0x380 fs/namespace.c:2416
 do_new_mount fs/namespace.c:2483 [inline]
 do_mount+0x160a/0x2bc0 fs/namespace.c:2799
 ksys_mount+0xdb/0x150 fs/namespace.c:3015
 __do_sys_mount fs/namespace.c:3029 [inline]
 __se_sys_mount fs/namespace.c:3026 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3026
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: cc 48 8b 05 71 ce 7e 01 48 85 c0 74 6f 48 8b 05 cd c9 7e 01 48 85 c0 74 63 64 48 8b 04 25 f8 ff ff ff 48 85 c0 74 5a 48 8b 40 <30> 48 85 c0 74 4c 8b 88 38 01 00 00 85 c9 74 42 48 8b 88 c0 00 00
RSP: 002b:00007fecce8cbc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045af49
RDX: 0000000020000140 RSI: 0000000020000000 RDI: 0000000000000000
RBP: 000000000075bfc8 R08: 0000000020000580 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fecce8cc6d4
R13: 00000000004c84ee R14: 00000000004e0740 R15: 00000000ffffffff
INFO: task syz-executor.5:26337 blocked for more than 140 seconds.
      Not tainted 4.19.94-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.5  D29976 26337   8136 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2826 [inline]
 __schedule+0x866/0x1dc0 kernel/sched/core.c:3515
 schedule+0x92/0x1c0 kernel/sched/core.c:3559
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
 rwsem_down_write_failed+0x774/0xc30 kernel/locking/rwsem-xadd.c:618
 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+0x53/0x90 kernel/locking/rwsem.c:72
 inode_lock include/linux/fs.h:747 [inline]
 vfs_setxattr+0x98/0x100 fs/xattr.c:218
 setxattr+0x26f/0x380 fs/xattr.c:450
 path_setxattr+0x197/0x1b0 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+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45af49
Code: cc 48 8b 05 71 ce 7e 01 48 85 c0 74 6f 48 8b 05 cd c9 7e 01 48 85 c0 74 63 64 48 8b 04 25 f8 ff ff ff 48 85 c0 74 5a 48 8b 40 <30> 48 85 c0 74 4c 8b 88 38 01 00 00 85 c9 74 42 48 8b 88 c0 00 00
RSP: 002b:00007fecce8aac78 EFLAGS: 00000246 ORIG_RAX: 00000000000000bc
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 000000000045af49
RDX: 0000000000000000 RSI: 0000000020000380 RDI: 0000000020000340
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fecce8ab6d4
R13: 00000000004d5028 R14: 00000000004e5dc8 R15: 00000000ffffffff

Showing all locks held in the system:
1 lock held by khungtaskd/1083:
 #0: 00000000286f392f (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4438
1 lock held by rsyslogd/7954:
 #0: 000000000688ce06 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767
2 locks held by getty/8076:
 #0: 000000007cf00b69 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000f45ff9ef (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8077:
 #0: 00000000c9cab46d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000008b13e54f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8078:
 #0: 00000000160e2dda (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 000000002e10626f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8079:
 #0: 0000000056706ba4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000d3f9ba03 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8080:
 #0: 000000005053873e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000c3bdc2ec (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8081:
 #0: 0000000018b12fd6 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000d7bb5dc7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by getty/8082:
 #0: 00000000b1dac4af (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
 #1: 00000000c3368187 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2154
2 locks held by syz-executor.5/26092:
 #0: 000000000ede26be (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1578 [inline]
 #0: 000000000ede26be (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
 #1: 00000000a873491b (&sb->s_type->i_mutex_key#21){+.+.}, at: inode_lock include/linux/fs.h:747 [inline]
 #1: 00000000a873491b (&sb->s_type->i_mutex_key#21){+.+.}, at: vfs_setxattr+0x98/0x100 fs/xattr.c:218
1 lock held by syz-executor.5/26127:
 #0: 00000000a873491b (&sb->s_type->i_mutex_key#21){+.+.}, at: inode_lock include/linux/fs.h:747 [inline]
 #0: 00000000a873491b (&sb->s_type->i_mutex_key#21){+.+.}, at: lock_mount+0x8c/0x2e0 fs/namespace.c:2039
2 locks held by syz-executor.5/26337:
 #0: 000000000ede26be (sb_writers#17){.+.+}, at: sb_start_write include/linux/fs.h:1578 [inline]
 #0: 000000000ede26be (sb_writers#17){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:360
 #1: 00000000a873491b (&sb->s_type->i_mutex_key#21){+.+.}, at: inode_lock include/linux/fs.h:747 [inline]
 #1: 00000000a873491b (&sb->s_type->i_mutex_key#21){+.+.}, at: vfs_setxattr+0x98/0x100 fs/xattr.c:218

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

NMI backtrace for cpu 1
CPU: 1 PID: 1083 Comm: khungtaskd Not tainted 4.19.94-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+0x197/0x210 lib/dump_stack.c:118
 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x1b0/0x1f8 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:146 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
 watchdog+0x9df/0xee0 kernel/hung_task.c:287
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 31 Comm: kworker/u4:2 Not tainted 4.19.94-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_nc_worker
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:789 [inline]
RIP: 0010:lock_release+0x45d/0xa30 kernel/locking/lockdep.c:3925
Code: 85 e3 03 00 00 48 c7 c0 c8 5b f2 88 48 ba 00 00 00 00 00 fc ff df 41 c7 84 24 7c 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 <0f> 85 a7 03 00 00 48 83 3d ed e4 9f 07 00 0f 84 65 02 00 00 48 8b
RSP: 0018:ffff8880a9a0fc18 EFLAGS: 00000046
RAX: 1ffffffff11e4b79 RBX: 1ffff11015341f89 RCX: 1ffff1101533f52e
RDX: dffffc0000000000 RSI: 0000000000000003 RDI: ffff8880a99fa97c
RBP: ffff8880a9a0fcd0 R08: ffff8880a99fa100 R09: 0000000000000002
R10: ffffed1015d04732 R11: ffff8880ae823993 R12: ffff8880a99fa100
R13: ffffffff873960ea R14: 0000000000000003 R15: ffff8880a9a0fca8
FS:  0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffff600400 CR3: 00000000842e7000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 rcu_lock_release include/linux/rcupdate.h:247 [inline]
 rcu_read_unlock include/linux/rcupdate.h:681 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:423 [inline]
 batadv_nc_worker+0x225/0x760 net/batman-adv/network-coding.c:730
 process_one_work+0x989/0x1750 kernel/workqueue.c:2153
 worker_thread+0x98/0xe40 kernel/workqueue.c:2296
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/01/10 01:50 linux-4.19.y cb1f9a169a0e 4de4e9f0 .config console log report ci2-linux-4-19
2019/11/09 01:06 linux-4.19.y 5ee93551c703 1e35461e .config console log report ci2-linux-4-19
2019/09/27 10:49 linux-4.19.y d573e8a79f70 2f1548bc .config console log report ci2-linux-4-19
2019/09/11 02:25 linux-4.19.y ee809c7e0895 a60cb4cd .config console log report ci2-linux-4-19
2019/09/01 14:51 linux-4.19.y 97ab07e11fbf bad3cce2 .config console log report ci2-linux-4-19
* Struck through repros no longer work on HEAD.