INFO: task hung in lock_mount
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syzbot
Sep 1, 2019, 11:52:07 AM9/1/19
to syzkaller...@googlegroups.com
Hello,
syzbot found the following crash on:
HEAD commit: 97ab07e1 Linux 4.19.69
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11a59a46600000
kernel config: https://syzkaller.appspot.com/x/.config?x=a73820df154c3af
dashboard link: https://syzkaller.appspot.com/bug?extid=51860817423898027428
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+518608...@syzkaller.appspotmail.com
INFO: task syz-executor.4:21499 blocked for more than 140 seconds.
Not tainted 4.19.69 #43
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D27848 21499 7676 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
__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: 0033:0x459879
Code: 48 39 f7 72 ed 66 0f 3a 61 4e ff 0c 4c 39 c9 77 9a 48 8d 7e ff 48 01
cf 4c 29 d7 49 89 3b c3 cc cc 48 8b 74 24 08 48 8b 5c 24 <10> 8a 44 24 20
4c 8d 44 24 28 e9 28 00 00 00 cc cc cc cc cc cc cc
RSP: 002b:00007f7a0ff00c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459879
RDX: 0000000020000100 RSI: 0000000020000040 RDI: 0000000000000000
RBP: 000000000075bfc8 R08: 00000000200005c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7a0ff016d4
R13: 00000000004c5e2f R14: 00000000004da930 R15: 00000000ffffffff
INFO: task syz-executor.4:21500 blocked for more than 140 seconds.
Not tainted 4.19.69 #43
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D29160 21500 7676 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
__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: 0033:0x459879
Code: 48 39 f7 72 ed 66 0f 3a 61 4e ff 0c 4c 39 c9 77 9a 48 8d 7e ff 48 01
cf 4c 29 d7 49 89 3b c3 cc cc 48 8b 74 24 08 48 8b 5c 24 <10> 8a 44 24 20
4c 8d 44 24 28 e9 28 00 00 00 cc cc cc cc cc cc cc
RSP: 002b:00007f7a0fedfc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459879
RDX: 0000000020000100 RSI: 0000000020000200 RDI: 0000000000000000
RBP: 000000000075c070 R08: 0000000020000240 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7a0fee06d4
R13: 00000000004c5ea4 R14: 00000000004daa08 R15: 00000000ffffffff
INFO: task syz-executor.4:21501 blocked for more than 140 seconds.
Not tainted 4.19.69 #43
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D28408 21501 7676 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
__rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
rwsem_down_read_failed+0x21b/0x3c0 kernel/locking/rwsem-xadd.c:309
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+0x49/0xb0 kernel/locking/rwsem.c:26
inode_lock_shared include/linux/fs.h:757 [inline]
lookup_slow+0x4a/0x80 fs/namei.c:1687
walk_component+0x747/0x2000 fs/namei.c:1810
link_path_walk.part.0+0x980/0x1330 fs/namei.c:2141
link_path_walk fs/namei.c:2269 [inline]
path_lookupat.isra.0+0xe3/0x8d0 fs/namei.c:2317
filename_lookup+0x1b0/0x410 fs/namei.c:2348
user_path_at_empty+0x43/0x50 fs/namei.c:2608
user_path_at include/linux/namei.h:57 [inline]
vfs_statx+0x129/0x200 fs/stat.c:185
vfs_stat include/linux/fs.h:3128 [inline]
__do_sys_newstat+0xa4/0x130 fs/stat.c:337
__se_sys_newstat fs/stat.c:333 [inline]
__x64_sys_newstat+0x54/0x80 fs/stat.c:333
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459879
Code: 48 39 f7 72 ed 66 0f 3a 61 4e ff 0c 4c 39 c9 77 9a 48 8d 7e ff 48 01
cf 4c 29 d7 49 89 3b c3 cc cc 48 8b 74 24 08 48 8b 5c 24 <10> 8a 44 24 20
4c 8d 44 24 28 e9 28 00 00 00 cc cc cc cc cc cc cc
RSP: 002b:00007f7a0febec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000459879
RDX: 0000000000000000 RSI: 0000000020000280 RDI: 00000000200000c0
RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7a0febf6d4
R13: 00000000004e62bb R14: 00000000004df508 R15: 00000000ffffffff
Showing all locks held in the system:
1 lock held by khungtaskd/1037:
#0: 000000004c4888b5 (rcu_read_lock){....}, at:
debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4435
1 lock held by rsyslogd/7500:
#0: 0000000003e6bd3a (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110
fs/file.c:767
2 locks held by getty/7622:
#0: 00000000a8a8b338 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000edc28120 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7623:
#0: 00000000b2356259 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000ca696143 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7624:
#0: 000000004dce74a3 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 0000000093e915a8 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7625:
#0: 00000000242fef75 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000fb7b0038 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7626:
#0: 00000000fc417627 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000a9a77c8d (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7627:
#0: 0000000068dba301 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000008de55073 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7628:
#0: 00000000c758817c (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000000982623a (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by syz-executor.4/21466:
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at:
inode_lock_shared include/linux/fs.h:757 [inline]
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at:
lookup_slow+0x4a/0x80 fs/namei.c:1687
#1: 0000000091bc8d6b (&sb->s_type->i_mutex_key#29){++++}, at:
inode_lock_shared include/linux/fs.h:757 [inline]
#1: 0000000091bc8d6b (&sb->s_type->i_mutex_key#29){++++}, at:
lookup_slow+0x4a/0x80 fs/namei.c:1687
1 lock held by syz-executor.4/21499:
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at: inode_lock
include/linux/fs.h:747 [inline]
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at:
lock_mount+0x8c/0x2e0 fs/namespace.c:2039
1 lock held by syz-executor.4/21500:
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at: inode_lock
include/linux/fs.h:747 [inline]
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at:
lock_mount+0x8c/0x2e0 fs/namespace.c:2039
1 lock held by syz-executor.4/21501:
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at:
inode_lock_shared include/linux/fs.h:757 [inline]
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at:
lookup_slow+0x4a/0x80 fs/namei.c:1687
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 1037 Comm: khungtaskd Not tainted 4.19.69 #43
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+0x172/0x1f0 lib/dump_stack.c:113
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 skipped: idling at native_safe_halt+0xe/0x10
arch/x86/include/asm/irqflags.h:60
---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot found the following crash on:
HEAD commit: 97ab07e1 Linux 4.19.69
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=11a59a46600000
kernel config: https://syzkaller.appspot.com/x/.config?x=a73820df154c3af
dashboard link: https://syzkaller.appspot.com/bug?extid=51860817423898027428
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+518608...@syzkaller.appspotmail.com
INFO: task syz-executor.4:21499 blocked for more than 140 seconds.
Not tainted 4.19.69 #43
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D27848 21499 7676 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
__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: 0033:0x459879
Code: 48 39 f7 72 ed 66 0f 3a 61 4e ff 0c 4c 39 c9 77 9a 48 8d 7e ff 48 01
cf 4c 29 d7 49 89 3b c3 cc cc 48 8b 74 24 08 48 8b 5c 24 <10> 8a 44 24 20
4c 8d 44 24 28 e9 28 00 00 00 cc cc cc cc cc cc cc
RSP: 002b:00007f7a0ff00c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459879
RDX: 0000000020000100 RSI: 0000000020000040 RDI: 0000000000000000
RBP: 000000000075bfc8 R08: 00000000200005c0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7a0ff016d4
R13: 00000000004c5e2f R14: 00000000004da930 R15: 00000000ffffffff
INFO: task syz-executor.4:21500 blocked for more than 140 seconds.
Not tainted 4.19.69 #43
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D29160 21500 7676 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
__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: 0033:0x459879
Code: 48 39 f7 72 ed 66 0f 3a 61 4e ff 0c 4c 39 c9 77 9a 48 8d 7e ff 48 01
cf 4c 29 d7 49 89 3b c3 cc cc 48 8b 74 24 08 48 8b 5c 24 <10> 8a 44 24 20
4c 8d 44 24 28 e9 28 00 00 00 cc cc cc cc cc cc cc
RSP: 002b:00007f7a0fedfc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459879
RDX: 0000000020000100 RSI: 0000000020000200 RDI: 0000000000000000
RBP: 000000000075c070 R08: 0000000020000240 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7a0fee06d4
R13: 00000000004c5ea4 R14: 00000000004daa08 R15: 00000000ffffffff
INFO: task syz-executor.4:21501 blocked for more than 140 seconds.
Not tainted 4.19.69 #43
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D28408 21501 7676 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2826 [inline]
__schedule+0x866/0x1dc0 kernel/sched/core.c:3474
schedule+0x92/0x1c0 kernel/sched/core.c:3518
__rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
rwsem_down_read_failed+0x21b/0x3c0 kernel/locking/rwsem-xadd.c:309
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+0x49/0xb0 kernel/locking/rwsem.c:26
inode_lock_shared include/linux/fs.h:757 [inline]
lookup_slow+0x4a/0x80 fs/namei.c:1687
walk_component+0x747/0x2000 fs/namei.c:1810
link_path_walk.part.0+0x980/0x1330 fs/namei.c:2141
link_path_walk fs/namei.c:2269 [inline]
path_lookupat.isra.0+0xe3/0x8d0 fs/namei.c:2317
filename_lookup+0x1b0/0x410 fs/namei.c:2348
user_path_at_empty+0x43/0x50 fs/namei.c:2608
user_path_at include/linux/namei.h:57 [inline]
vfs_statx+0x129/0x200 fs/stat.c:185
vfs_stat include/linux/fs.h:3128 [inline]
__do_sys_newstat+0xa4/0x130 fs/stat.c:337
__se_sys_newstat fs/stat.c:333 [inline]
__x64_sys_newstat+0x54/0x80 fs/stat.c:333
do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459879
Code: 48 39 f7 72 ed 66 0f 3a 61 4e ff 0c 4c 39 c9 77 9a 48 8d 7e ff 48 01
cf 4c 29 d7 49 89 3b c3 cc cc 48 8b 74 24 08 48 8b 5c 24 <10> 8a 44 24 20
4c 8d 44 24 28 e9 28 00 00 00 cc cc cc cc cc cc cc
RSP: 002b:00007f7a0febec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000459879
RDX: 0000000000000000 RSI: 0000000020000280 RDI: 00000000200000c0
RBP: 000000000075c118 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f7a0febf6d4
R13: 00000000004e62bb R14: 00000000004df508 R15: 00000000ffffffff
Showing all locks held in the system:
1 lock held by khungtaskd/1037:
#0: 000000004c4888b5 (rcu_read_lock){....}, at:
debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4435
1 lock held by rsyslogd/7500:
#0: 0000000003e6bd3a (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110
fs/file.c:767
2 locks held by getty/7622:
#0: 00000000a8a8b338 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000edc28120 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7623:
#0: 00000000b2356259 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000ca696143 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7624:
#0: 000000004dce74a3 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 0000000093e915a8 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7625:
#0: 00000000242fef75 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000fb7b0038 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7626:
#0: 00000000fc417627 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 00000000a9a77c8d (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7627:
#0: 0000000068dba301 (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000008de55073 (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by getty/7628:
#0: 00000000c758817c (&tty->ldisc_sem){++++}, at:
ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:362
#1: 000000000982623a (&ldata->atomic_read_lock){+.+.}, at:
n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154
2 locks held by syz-executor.4/21466:
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at:
inode_lock_shared include/linux/fs.h:757 [inline]
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at:
lookup_slow+0x4a/0x80 fs/namei.c:1687
#1: 0000000091bc8d6b (&sb->s_type->i_mutex_key#29){++++}, at:
inode_lock_shared include/linux/fs.h:757 [inline]
#1: 0000000091bc8d6b (&sb->s_type->i_mutex_key#29){++++}, at:
lookup_slow+0x4a/0x80 fs/namei.c:1687
1 lock held by syz-executor.4/21499:
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at: inode_lock
include/linux/fs.h:747 [inline]
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at:
lock_mount+0x8c/0x2e0 fs/namespace.c:2039
1 lock held by syz-executor.4/21500:
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at: inode_lock
include/linux/fs.h:747 [inline]
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at:
lock_mount+0x8c/0x2e0 fs/namespace.c:2039
1 lock held by syz-executor.4/21501:
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at:
inode_lock_shared include/linux/fs.h:757 [inline]
#0: 00000000c138ad80 (&ovl_i_mutex_dir_key[depth]){++++}, at:
lookup_slow+0x4a/0x80 fs/namei.c:1687
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 1037 Comm: khungtaskd Not tainted 4.19.69 #43
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+0x172/0x1f0 lib/dump_stack.c:113
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 skipped: idling at native_safe_halt+0xe/0x10
arch/x86/include/asm/irqflags.h:60
---
This bug is generated by a bot. It may contain errors.
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syzbot
May 8, 2020, 9:51:09 PM5/8/20
to syzkaller...@googlegroups.com
Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.
Crashes did not happen for a while, no reproducer and no activity.
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