[v6.1] INFO: task hung in ext4_stop_mmpd
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syzbot
Jul 4, 2024, 11:39:19 AM (3 days ago) Jul 4
to syzkaller...@googlegroups.com
Hello,
syzbot found the following issue on:
HEAD commit: 99e6a620de00 Linux 6.1.96
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=105e9712980000
kernel config: https://syzkaller.appspot.com/x/.config?x=8695f134c8d5830a
dashboard link: https://syzkaller.appspot.com/bug?extid=6fee2d75fb514abd334e
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/58c038f7d058/disk-99e6a620.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6f70b0b239b0/vmlinux-99e6a620.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c1423cf0fcc7/bzImage-99e6a620.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6fee2d...@syzkaller.appspotmail.com
INFO: task syz-executor:10871 blocked for more than 143 seconds.
Not tainted 6.1.96-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:20232 pid:10871 ppid:1 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x142d/0x4550 kernel/sched/core.c:6558
schedule+0xbf/0x180 kernel/sched/core.c:6634
schedule_timeout+0xac/0x300 kernel/time/timer.c:1941
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x350/0x610 kernel/sched/completion.c:138
kthread_stop+0x1ab/0x690 kernel/kthread.c:709
ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:261
ext4_put_super+0xb49/0x10e0 fs/ext4/super.c:1293
generic_shutdown_super+0x130/0x340 fs/super.c:501
kill_block_super+0x7a/0xe0 fs/super.c:1459
deactivate_locked_super+0xa0/0x110 fs/super.c:332
cleanup_mnt+0x490/0x520 fs/namespace.c:1186
task_work_run+0x246/0x300 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5d4c576f07
RSP: 002b:00007ffdc3c9fda8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f5d4c5e3515 RCX: 00007f5d4c576f07
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdc3c9fe60
RBP: 00007ffdc3c9fe60 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdc3ca0f30
R13: 00007f5d4c5e3515 R14: 00000000000a3ecb R15: 000000000000000e
</TASK>
INFO: task syz-executor:14832 blocked for more than 143 seconds.
Not tainted 6.1.96-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:19832 pid:14832 ppid:1 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x142d/0x4550 kernel/sched/core.c:6558
schedule+0xbf/0x180 kernel/sched/core.c:6634
schedule_timeout+0xac/0x300 kernel/time/timer.c:1941
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x350/0x610 kernel/sched/completion.c:138
kthread_stop+0x1ab/0x690 kernel/kthread.c:709
ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:261
ext4_put_super+0xb49/0x10e0 fs/ext4/super.c:1293
generic_shutdown_super+0x130/0x340 fs/super.c:501
kill_block_super+0x7a/0xe0 fs/super.c:1459
deactivate_locked_super+0xa0/0x110 fs/super.c:332
cleanup_mnt+0x490/0x520 fs/namespace.c:1186
task_work_run+0x246/0x300 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe71e776f07
RSP: 002b:00007ffd7ed1a008 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fe71e7e3515 RCX: 00007fe71e776f07
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd7ed1a0c0
RBP: 00007ffd7ed1a0c0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd7ed1b190
R13: 00007fe71e7e3515 R14: 00000000000a23b4 R15: 000000000000000f
</TASK>
INFO: task kmmpd-loop0:16897 blocked for more than 144 seconds.
Not tainted 6.1.96-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kmmpd-loop0 state:D stack:28088 pid:16897 ppid:2 flags:0x00024000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x142d/0x4550 kernel/sched/core.c:6558
schedule+0xbf/0x180 kernel/sched/core.c:6634
percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
__percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
__sb_start_write include/linux/fs.h:1891 [inline]
sb_start_write include/linux/fs.h:1966 [inline]
write_mmp_block+0x2ee/0x390 fs/ext4/mmp.c:66
kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
INFO: task kmmpd-loop4:17228 blocked for more than 144 seconds.
Not tainted 6.1.96-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kmmpd-loop4 state:D stack:28088 pid:17228 ppid:2 flags:0x00024000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x142d/0x4550 kernel/sched/core.c:6558
schedule+0xbf/0x180 kernel/sched/core.c:6634
percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
__percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
__sb_start_write include/linux/fs.h:1891 [inline]
sb_start_write include/linux/fs.h:1966 [inline]
write_mmp_block+0x2ee/0x390 fs/ext4/mmp.c:66
kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8d12ae90 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8d12b690 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
#0: ffffffff8d12acc0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8d12acc0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8d12acc0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
2 locks held by getty/3304:
#0: ffff88814bdab098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/5388:
#0: ffff88805c70c0e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
1 lock held by syz-executor/10871:
#0: ffff888078f160e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
1 lock held by syz-executor/14832:
#0: ffff88807b5460e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
1 lock held by kmmpd-loop0/16897:
#0: ffff88807b546460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
1 lock held by kmmpd-loop4/17228:
#0: ffff888078f16460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
1 lock held by kmmpd-loop2/17621:
#0: ffff88805c70c460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
1 lock held by syz-executor/19103:
#0: ffff88807d6540e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
1 lock held by kmmpd-loop3/21225:
#0: ffff88807d654460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
2 locks held by kworker/u4:19/22734:
#0: ffff8880b983aa18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa8/0x140 kernel/sched/core.c:545
#1: ffff8880b9827788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3a3/0x770 kernel/sched/psi.c:988
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.96-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf88/0xfd0 kernel/hung_task.c:377
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9713 Comm: kworker/u4:0 Not tainted 6.1.96-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:mark_held_locks kernel/locking/lockdep.c:4222 [inline]
RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:4256 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0x378/0x7a0 kernel/locking/lockdep.c:4315
Code: 64 24 10 49 8d 9c 24 e0 0a 00 00 49 81 c4 00 0b 00 00 45 31 ed 49 83 fd 31 0f 83 a1 00 00 00 4c 89 e0 48 c1 e8 03 0f b6 04 10 <84> c0 75 50 8b 43 20 a9 00 00 04 00 74 28 31 d2 a9 00 00 03 00 0f
RSP: 0018:ffffc90004e7f9e0 EFLAGS: 00000802
RAX: 0000000000000000 RBX: ffff888017694688 RCX: ffffffff816ad45a
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff9049c2f0
RBP: ffffc90004e7fa88 R08: dffffc0000000000 R09: fffffbfff209385f
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880176946a8
R13: 0000000000000001 R14: ffff888017694658 R15: 1ffff11002ed28cb
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020a33030 CR3: 000000000ce8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
trace_hardirqs_on+0x34/0x40 kernel/trace/trace_preemptirq.c:49
__local_bh_enable_ip+0x164/0x1f0 kernel/softirq.c:401
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_nc_purge_paths+0x30e/0x3b0 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x324/0x610 net/batman-adv/network-coding.c:720
process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
---
This report 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 issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want to overwrite report's subsystems, reply with:
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(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
syzbot found the following issue on:
HEAD commit: 99e6a620de00 Linux 6.1.96
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=105e9712980000
kernel config: https://syzkaller.appspot.com/x/.config?x=8695f134c8d5830a
dashboard link: https://syzkaller.appspot.com/bug?extid=6fee2d75fb514abd334e
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
Unfortunately, I don't have any reproducer for this issue yet.
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/58c038f7d058/disk-99e6a620.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/6f70b0b239b0/vmlinux-99e6a620.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c1423cf0fcc7/bzImage-99e6a620.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6fee2d...@syzkaller.appspotmail.com
INFO: task syz-executor:10871 blocked for more than 143 seconds.
Not tainted 6.1.96-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:20232 pid:10871 ppid:1 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x142d/0x4550 kernel/sched/core.c:6558
schedule+0xbf/0x180 kernel/sched/core.c:6634
schedule_timeout+0xac/0x300 kernel/time/timer.c:1941
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x350/0x610 kernel/sched/completion.c:138
kthread_stop+0x1ab/0x690 kernel/kthread.c:709
ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:261
ext4_put_super+0xb49/0x10e0 fs/ext4/super.c:1293
generic_shutdown_super+0x130/0x340 fs/super.c:501
kill_block_super+0x7a/0xe0 fs/super.c:1459
deactivate_locked_super+0xa0/0x110 fs/super.c:332
cleanup_mnt+0x490/0x520 fs/namespace.c:1186
task_work_run+0x246/0x300 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5d4c576f07
RSP: 002b:00007ffdc3c9fda8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007f5d4c5e3515 RCX: 00007f5d4c576f07
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdc3c9fe60
RBP: 00007ffdc3c9fe60 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdc3ca0f30
R13: 00007f5d4c5e3515 R14: 00000000000a3ecb R15: 000000000000000e
</TASK>
INFO: task syz-executor:14832 blocked for more than 143 seconds.
Not tainted 6.1.96-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:19832 pid:14832 ppid:1 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x142d/0x4550 kernel/sched/core.c:6558
schedule+0xbf/0x180 kernel/sched/core.c:6634
schedule_timeout+0xac/0x300 kernel/time/timer.c:1941
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common kernel/sched/completion.c:106 [inline]
wait_for_common kernel/sched/completion.c:117 [inline]
wait_for_completion+0x350/0x610 kernel/sched/completion.c:138
kthread_stop+0x1ab/0x690 kernel/kthread.c:709
ext4_stop_mmpd+0x43/0xb0 fs/ext4/mmp.c:261
ext4_put_super+0xb49/0x10e0 fs/ext4/super.c:1293
generic_shutdown_super+0x130/0x340 fs/super.c:501
kill_block_super+0x7a/0xe0 fs/super.c:1459
deactivate_locked_super+0xa0/0x110 fs/super.c:332
cleanup_mnt+0x490/0x520 fs/namespace.c:1186
task_work_run+0x246/0x300 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe71e776f07
RSP: 002b:00007ffd7ed1a008 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: 0000000000000000 RBX: 00007fe71e7e3515 RCX: 00007fe71e776f07
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd7ed1a0c0
RBP: 00007ffd7ed1a0c0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd7ed1b190
R13: 00007fe71e7e3515 R14: 00000000000a23b4 R15: 000000000000000f
</TASK>
INFO: task kmmpd-loop0:16897 blocked for more than 144 seconds.
Not tainted 6.1.96-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kmmpd-loop0 state:D stack:28088 pid:16897 ppid:2 flags:0x00024000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x142d/0x4550 kernel/sched/core.c:6558
schedule+0xbf/0x180 kernel/sched/core.c:6634
percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
__percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
__sb_start_write include/linux/fs.h:1891 [inline]
sb_start_write include/linux/fs.h:1966 [inline]
write_mmp_block+0x2ee/0x390 fs/ext4/mmp.c:66
kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
INFO: task kmmpd-loop4:17228 blocked for more than 144 seconds.
Not tainted 6.1.96-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kmmpd-loop4 state:D stack:28088 pid:17228 ppid:2 flags:0x00024000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x142d/0x4550 kernel/sched/core.c:6558
schedule+0xbf/0x180 kernel/sched/core.c:6634
percpu_rwsem_wait+0x3b9/0x450 kernel/locking/percpu-rwsem.c:162
__percpu_down_read+0xe6/0x130 kernel/locking/percpu-rwsem.c:177
percpu_down_read include/linux/percpu-rwsem.h:65 [inline]
__sb_start_write include/linux/fs.h:1891 [inline]
sb_start_write include/linux/fs.h:1966 [inline]
write_mmp_block+0x2ee/0x390 fs/ext4/mmp.c:66
kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8d12ae90 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8d12b690 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
#0: ffffffff8d12acc0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#0: ffffffff8d12acc0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#0: ffffffff8d12acc0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494
2 locks held by getty/3304:
#0: ffff88814bdab098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198
1 lock held by syz-executor/5388:
#0: ffff88805c70c0e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
1 lock held by syz-executor/10871:
#0: ffff888078f160e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
1 lock held by syz-executor/14832:
#0: ffff88807b5460e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
1 lock held by kmmpd-loop0/16897:
#0: ffff88807b546460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
1 lock held by kmmpd-loop4/17228:
#0: ffff888078f16460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
1 lock held by kmmpd-loop2/17621:
#0: ffff88805c70c460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
1 lock held by syz-executor/19103:
#0: ffff88807d6540e0 (&type->s_umount_key#31){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362
1 lock held by kmmpd-loop3/21225:
#0: ffff88807d654460 (sb_writers#4){++++}-{0:0}, at: kmmpd+0x263/0xa70 fs/ext4/mmp.c:246
2 locks held by kworker/u4:19/22734:
#0: ffff8880b983aa18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xa8/0x140 kernel/sched/core.c:545
#1: ffff8880b9827788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3a3/0x770 kernel/sched/psi.c:988
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.96-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xf88/0xfd0 kernel/hung_task.c:377
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 9713 Comm: kworker/u4:0 Not tainted 6.1.96-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:mark_held_locks kernel/locking/lockdep.c:4222 [inline]
RIP: 0010:__trace_hardirqs_on_caller kernel/locking/lockdep.c:4256 [inline]
RIP: 0010:lockdep_hardirqs_on_prepare+0x378/0x7a0 kernel/locking/lockdep.c:4315
Code: 64 24 10 49 8d 9c 24 e0 0a 00 00 49 81 c4 00 0b 00 00 45 31 ed 49 83 fd 31 0f 83 a1 00 00 00 4c 89 e0 48 c1 e8 03 0f b6 04 10 <84> c0 75 50 8b 43 20 a9 00 00 04 00 74 28 31 d2 a9 00 00 03 00 0f
RSP: 0018:ffffc90004e7f9e0 EFLAGS: 00000802
RAX: 0000000000000000 RBX: ffff888017694688 RCX: ffffffff816ad45a
RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff9049c2f0
RBP: ffffc90004e7fa88 R08: dffffc0000000000 R09: fffffbfff209385f
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8880176946a8
R13: 0000000000000001 R14: ffff888017694658 R15: 1ffff11002ed28cb
FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020a33030 CR3: 000000000ce8e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
trace_hardirqs_on+0x34/0x40 kernel/trace/trace_preemptirq.c:49
__local_bh_enable_ip+0x164/0x1f0 kernel/softirq.c:401
spin_unlock_bh include/linux/spinlock.h:396 [inline]
batadv_nc_purge_paths+0x30e/0x3b0 net/batman-adv/network-coding.c:471
batadv_nc_worker+0x324/0x610 net/batman-adv/network-coding.c:720
process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
</TASK>
---
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