[v6.1] INFO: task hung in d_alloc_parallel (2)

Hello,

syzbot found the following issue on:

HEAD commit: 7c15117f9468 Linux 6.1.115
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1494f630580000
kernel config: https://syzkaller.appspot.com/x/.config?x=29e1a92919c0b720
dashboard link: https://syzkaller.appspot.com/bug?extid=30f73869d6de512e814b
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=140386a7980000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11452d5f980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b2308050ad83/disk-7c15117f.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/172ef416598b/vmlinux-7c15117f.xz
kernel image: https://storage.googleapis.com/syzbot-assets/77848bcfaf0c/Image-7c15117f.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/1e6509285795/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: [email protected]

INFO: task syz-executor299:4306 blocked for more than 143 seconds.
Not tainted 6.1.115-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor299 state:D
stack:0 pid:4306 ppid:4291 flags:0x00000005
Call trace:
__switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
context_switch kernel/sched/core.c:5241 [inline]
__schedule+0xef4/0x1d44 kernel/sched/core.c:6558
schedule+0xc4/0x170 kernel/sched/core.c:6634
d_wait_lookup+0x1a0/0x27c fs/dcache.c:2632
d_alloc_parallel+0x9b0/0x1184 fs/dcache.c:2714
__lookup_slow+0x108/0x374 fs/namei.c:1675
lookup_slow+0x60/0x84 fs/namei.c:1707
walk_component fs/namei.c:1998 [inline]
link_path_walk+0x830/0xcc8 fs/namei.c:2325
path_openat+0x1c8/0x2548 fs/namei.c:3779
do_filp_open+0x1bc/0x3cc fs/namei.c:3810
do_sys_openat2+0x128/0x3e0 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
INFO: task syz-executor299:4307 blocked for more than 143 seconds.
Not tainted 6.1.115-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor299 state:D
stack:0 pid:4307 ppid:4294 flags:0x00000005
Call trace:
__switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
context_switch kernel/sched/core.c:5241 [inline]
__schedule+0xef4/0x1d44 kernel/sched/core.c:6558
schedule+0xc4/0x170 kernel/sched/core.c:6634
d_wait_lookup+0x1a0/0x27c fs/dcache.c:2632
d_alloc_parallel+0x9b0/0x1184 fs/dcache.c:2714
__lookup_slow+0x108/0x374 fs/namei.c:1675
lookup_slow+0x60/0x84 fs/namei.c:1707
walk_component fs/namei.c:1998 [inline]
link_path_walk+0x830/0xcc8 fs/namei.c:2325
path_openat+0x1c8/0x2548 fs/namei.c:3779
do_filp_open+0x1bc/0x3cc fs/namei.c:3810
do_sys_openat2+0x128/0x3e0 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
INFO: task syz-executor299:4308 blocked for more than 143 seconds.
Not tainted 6.1.115-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor299 state:D
stack:0 pid:4308 ppid:4292 flags:0x00000005
Call trace:
__switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
context_switch kernel/sched/core.c:5241 [inline]
__schedule+0xef4/0x1d44 kernel/sched/core.c:6558
schedule+0xc4/0x170 kernel/sched/core.c:6634
d_wait_lookup+0x1a0/0x27c fs/dcache.c:2632
d_alloc_parallel+0x9b0/0x1184 fs/dcache.c:2714
__lookup_slow+0x108/0x374 fs/namei.c:1675
lookup_slow+0x60/0x84 fs/namei.c:1707
walk_component fs/namei.c:1998 [inline]
link_path_walk+0x830/0xcc8 fs/namei.c:2325
path_openat+0x1c8/0x2548 fs/namei.c:3779
do_filp_open+0x1bc/0x3cc fs/namei.c:3810
do_sys_openat2+0x128/0x3e0 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585
INFO: task syz-executor299:4312 blocked for more than 143 seconds.
Not tainted 6.1.115-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor299 state:D
stack:0 pid:4312 ppid:4293 flags:0x00000005
Call trace:
__switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
context_switch kernel/sched/core.c:5241 [inline]
__schedule+0xef4/0x1d44 kernel/sched/core.c:6558
schedule+0xc4/0x170 kernel/sched/core.c:6634
d_wait_lookup+0x1a0/0x27c fs/dcache.c:2632
d_alloc_parallel+0x9b0/0x1184 fs/dcache.c:2714
__lookup_slow+0x108/0x374 fs/namei.c:1675
lookup_slow+0x60/0x84 fs/namei.c:1707
walk_component fs/namei.c:1998 [inline]
link_path_walk+0x830/0xcc8 fs/namei.c:2325
path_openat+0x1c8/0x2548 fs/namei.c:3779
do_filp_open+0x1bc/0x3cc fs/namei.c:3810
do_sys_openat2+0x128/0x3e0 fs/open.c:1318
do_sys_open fs/open.c:1334 [inline]
__do_sys_openat fs/open.c:1350 [inline]
__se_sys_openat fs/open.c:1345 [inline]
__arm64_sys_openat+0x1f0/0x240 fs/open.c:1345
__invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:204
el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0:
ffff800015ba5bf0
(
rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0:
ffff800015ba63f0
(
rcu_tasks_trace.tasks_gp_mutex
){+.+.}-{3:3}
, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:517
1 lock held by khungtaskd/28:
#0:
ffff800015ba5a20
(
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:349
2 locks held by getty/4055:
#0:
ffff0000d66f2098
(
&tty->ldisc_sem
){++++}-{0:0}
, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
#1:
ffff80001efd02f0
(
&ldata->atomic_read_lock
){+.+.}-{3:3}
, at: n_tty_read+0x414/0x1214 drivers/tty/n_tty.c:2198
4 locks held by syz-executor299/4296:
1 lock held by syz-executor299/4306:
#0:
ffff0000e4878198
(&type->i_mutex_dir_key#6){.+.+}-{3:3}
, at: inode_lock_shared include/linux/fs.h:768 [inline]
, at: lookup_slow+0x50/0x84 fs/namei.c:1706
1 lock held by syz-executor299/4299:
1 lock held by syz-executor299/4307:
#0: ffff0000e4878c48
(&type->i_mutex_dir_key#6){.+.+}-{3:3}
, at: inode_lock_shared include/linux/fs.h:768 [inline]
, at: lookup_slow+0x50/0x84 fs/namei.c:1706
1 lock held by syz-executor299/4301:
1 lock held by syz-executor299/4308:
#0:
ffff0000e48796f8 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:768 [inline]
ffff0000e48796f8 (&type->i_mutex_dir_key#6){.+.+}-{3:3}, at: lookup_slow+0x50/0x84 fs/namei.c:1706
1 lock held by syz-executor299/4304:
1 lock held by syz-executor299/4312:
#0:
ffff0000e487a1a8
(
&type->i_mutex_dir_key
#6
){.+.+}-{3:3}
, at: inode_lock_shared include/linux/fs.h:768 [inline]
, at: lookup_slow+0x50/0x84 fs/namei.c:1706
1 lock held by syz-executor299/4311:

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



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