[v6.6] INFO: task hung in __gfs2_lookup

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 5fa4793a2d2d Linux 6.6.119
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1243429a580000
kernel config: https://syzkaller.appspot.com/x/.config?x=691a6769a86ac817
dashboard link: https://syzkaller.appspot.com/bug?extid=751290054fe23f2a5317
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63699875f1dd/disk-5fa4793a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8506652fcb6f/vmlinux-5fa4793a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b30ceed1710/bzImage-5fa4793a.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+751290...@syzkaller.appspotmail.com

INFO: task syz-executor:5766 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor state:D stack:21608 pid:5766 ppid:1 flags:0x00004004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5380 [inline]
__schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
schedule+0xbd/0x170 kernel/sched/core.c:6773
bit_wait+0x11/0xd0 kernel/sched/wait_bit.c:199
__wait_on_bit+0xac/0x2d0 kernel/sched/wait_bit.c:49
out_of_line_wait_on_bit+0x123/0x170 kernel/sched/wait_bit.c:64
wait_on_bit include/linux/wait_bit.h:76 [inline]
gfs2_glock_wait+0xbd/0x2a0 fs/gfs2/glock.c:1380
gfs2_glock_nq_init fs/gfs2/glock.h:252 [inline]
__gfs2_lookup+0x118/0x270 fs/gfs2/inode.c:905
__lookup_slow+0x281/0x3b0 fs/namei.c:1702
lookup_slow+0x53/0x70 fs/namei.c:1719
walk_component+0x2be/0x3f0 fs/namei.c:2010
lookup_last fs/namei.c:2467 [inline]
path_lookupat+0x169/0x440 fs/namei.c:2491
filename_lookup+0x1f4/0x510 fs/namei.c:2520
user_path_at_empty+0x42/0x60 fs/namei.c:2917
user_path_at include/linux/namei.h:57 [inline]
ksys_umount fs/namespace.c:1921 [inline]
__do_sys_umount fs/namespace.c:1929 [inline]
__se_sys_umount fs/namespace.c:1927 [inline]
__x64_sys_umount+0xf5/0x170 fs/namespace.c:1927
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f9892d90a77
RSP: 002b:00007ffc4a9b2ff8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007f9892e13d7d RCX: 00007f9892d90a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc4a9b30b0
RBP: 00007ffc4a9b30b0 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc4a9b41a0
R13: 00007f9892e13d7d R14: 0000555590dec4a8 R15: 00007ffc4a9b6360
</TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
4 locks held by kworker/u4:8/2978:
2 locks held by getty/5528:
#0: ffff88814c9f30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
1 lock held by syz-executor/5766:
#0: ffff888058fbcb48 (&type->i_mutex_dir_key#27){++++}-{3:3}, at: inode_lock_shared include/linux/fs.h:814 [inline]
#0: ffff888058fbcb48 (&type->i_mutex_dir_key#27){++++}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1718
2 locks held by kworker/1:4/5818:
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc9000480fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc9000480fd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
3 locks held by kworker/0:4/5831:
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc900048efd00 (free_ipc_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc900048efd00 (free_ipc_work){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
3 locks held by syz.9.847/10865:
#0: ffff88806a703470 (&fc->uapi_mutex){+.+.}-{3:3}, at: __do_sys_fsconfig fs/fsopen.c:479 [inline]
#0: ffff88806a703470 (&fc->uapi_mutex){+.+.}-{3:3}, at: __se_sys_fsconfig+0x6d4/0x850 fs/fsopen.c:355
#1: ffff88807f1520e0 (&type->s_umount_key#32){++++}-{3:3}, at: vfs_cmd_reconfigure fs/fsopen.c:272 [inline]
#1: ffff88807f1520e0 (&type->s_umount_key#32){++++}-{3:3}, at: vfs_fsconfig_locked+0x164/0x320 fs/fsopen.c:302
#2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
#2: ffffffff8cd358f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x360/0x830 kernel/rcu/tree_exp.h:1004
1 lock held by syz.9.847/10882:
#0: ffff88807f1520e0 (&type->s_umount_key#32){++++}-{3:3}, at: do_remount fs/namespace.c:2924 [inline]
#0: ffff88807f1520e0 (&type->s_umount_key#32){++++}-{3:3}, at: path_mount+0xcd3/0xfe0 fs/namespace.c:3705
1 lock held by cmp/10899:

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5753 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__bitmap_andnot+0x151/0x350 lib/bitmap.c:286
Code: 74 05 e8 22 f8 c0 fd 4d 8b 64 2f 08 4d 89 f7 49 8d 7c 2e 08 48 89 f8 48 c1 e8 03 4d 89 ee 42 80 3c 28 00 74 05 e8 ff f7 c0 fd <4d> 8b 6c 2f 08 48 8b 44 24 08 48 8d 7c 28 08 48 89 f8 48 c1 e8 03
RSP: 0018:ffffc900001f0b00 EFLAGS: 00000046
RAX: 1ffffffff21aa658 RBX: 0000000000000000 RCX: ffff88802e8abc00
RDX: 0000000000000100 RSI: 0000000000004000 RDI: ffffffff90d532c0
RBP: 000000000000ee50 R08: ffffffff907c469f R09: 0000000000000000
R10: ffffffff907c4610 R11: fffffbfff20f88d4 R12: 0000000000000000
R13: dffffc0000000000 R14: dffffc0000000000 R15: ffffffff90d44468
FS: 0000555568187500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f10f6a536bc CR3: 00000000761ea000 CR4: 00000000003506e0
Call Trace:
<IRQ>
bitmap_andnot include/linux/bitmap.h:367 [inline]
__free_zapped_classes+0x2ae/0x2d0 kernel/locking/lockdep.c:6226
free_zapped_rcu+0xbe/0x240 kernel/locking/lockdep.c:6246
rcu_do_batch kernel/rcu/tree.c:2194 [inline]
rcu_core+0xcc4/0x1720 kernel/rcu/tree.c:2467
handle_softirqs+0x280/0x820 kernel/softirq.c:578
do_softirq+0xed/0x180 kernel/softirq.c:479
</IRQ>
<TASK>
__local_bh_enable_ip+0x178/0x1c0 kernel/softirq.c:406
tcp_recvmsg+0x220/0x810 net/ipv4/tcp.c:2605
inet_recvmsg+0x130/0x1e0 net/ipv4/af_inet.c:882
sock_recvmsg_nosec net/socket.c:1046 [inline]
sock_recvmsg net/socket.c:1068 [inline]
sock_read_iter+0x2b7/0x3b0 net/socket.c:1138
call_read_iter include/linux/fs.h:2012 [inline]
new_sync_read fs/read_write.c:389 [inline]
vfs_read+0x431/0x920 fs/read_write.c:470
ksys_read+0x147/0x250 fs/read_write.c:613
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f82a218e11d
Code: a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb bd e8 a8 48 00 00 0f 1f 84 00 00 00 00 00 80 3d 41 d4 22 00 00 74 17 31 c0 0f 05 <48> 3d 00 f0 ff ff 77 5b c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec
RSP: 002b:00007ffd766a7668 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f82a218e11d
RDX: 0000000000000004 RSI: 00007ffd766a767c RDI: 0000000000000003
RBP: 0000000000000000 R08: 00000000000001ce R09: 0000000000745d1e
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd766a7a90
R13: 0000000000000004 R14: 00007ffd766a767c R15: 00007ffd766a7710
</TASK>


---
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If the report is already addressed, let syzbot know by replying with:
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If the report is a duplicate of another one, reply with:
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If you want to undo deduplication, reply with:
#syz undup

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit: 5fa4793a2d2d Linux 6.6.119
git tree: linux-6.6.y

console output: https://syzkaller.appspot.com/x/log.txt?x=12a34afc580000

kernel config: https://syzkaller.appspot.com/x/.config?x=691a6769a86ac817
dashboard link: https://syzkaller.appspot.com/bug?extid=751290054fe23f2a5317
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13a38a9a580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=16a34afc580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/63699875f1dd/disk-5fa4793a.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8506652fcb6f/vmlinux-5fa4793a.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1b30ceed1710/bzImage-5fa4793a.xz

mounted in repro: https://storage.googleapis.com/syzbot-assets/2af4e74071f8/mount_0.gz
fsck result: failed (log: https://syzkaller.appspot.com/x/fsck.log?x=15a38a9a580000)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+751290...@syzkaller.appspotmail.com

INFO: task syz-executor:5890 blocked for more than 143 seconds.

Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:syz-executor state:D stack:21736 pid:5890 ppid:1 flags:0x00004004

RIP: 0033:0x7f8d73b90a77
RSP: 002b:00007ffe23954698 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 00007f8d73c13d7d RCX: 00007f8d73b90a77
RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffe23954750
RBP: 00007ffe23954750 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffe23955840
R13: 00007f8d73c13d7d R14: 000055558c41e4a8 R15: 00007ffe23957a00

</TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/29:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633

2 locks held by kworker/u4:6/1319:
5 locks held by kworker/u4:7/2974:
#0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
#1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6694
#2: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#2: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#2: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline]
#2: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: batadv_nc_worker+0xd2/0x610 net/batman-adv/network-coding.c:719
#3: ffffffff970c3e68 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x6c/0x4b0 lib/debugobjects.c:709
#4: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_enqueue kernel/sched/stats.h:143 [inline]
#4: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: enqueue_task+0x275/0x2c0 kernel/sched/core.c:2097
2 locks held by getty/5522:
#0: ffff88823bce08a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243

#1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217

1 lock held by syz-executor/5890:
#0: ffff888061da0ed0 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:814 [inline]
#0: ffff888061da0ed0 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1718

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

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
watchdog+0xf41/0xf80 kernel/hung_task.c:379
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>

Sending NMI from CPU 1 to CPUs 0:

NMI backtrace for cpu 0

CPU: 0 PID: 2974 Comm: kworker/u4:7 Not tainted syzkaller #0

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025

Workqueue: events_unbound cfg80211_wiphy_work
RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x60 kernel/kcov.c:215
Code: 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d 9c 92 c4 0c 48 89 de 5b e9 43 9d 56 00 cc cc cc f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d f0 24 7e 7e 65 8b 15 f1 24 7e 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc9000c3776d8 EFLAGS: 00000a06
RAX: ffffffff89dac2ac RBX: ffff88807d6760d0 RCX: 1ffff9200186eee4
RDX: ffff88807d6760d0 RSI: ffff8880789a1ca8 RDI: ffff88807a1a8e20
RBP: ffffc9000c377810 R08: ffff88807a1ab5b8 R09: 1ffffffff1c94425
R10: dffffc0000000000 R11: fffffbfff1c94426 R12: dffffc0000000000
R13: ffffc9000c377740 R14: ffff8880789a1ca8 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00007f78c37b8000 CR3: 000000002fc9a000 CR4: 00000000003506f0
Call Trace:
<TASK>
ieee80211_bss_info_update+0x9c/0x930 net/mac80211/scan.c:168
ieee80211_rx_bss_info net/mac80211/ibss.c:1124 [inline]
ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1613 [inline]
ieee80211_ibss_rx_queued_mgmt+0x17c9/0x2ac0 net/mac80211/ibss.c:1642
ieee80211_iface_process_skb net/mac80211/iface.c:1651 [inline]
ieee80211_iface_work+0x717/0xc70 net/mac80211/iface.c:1705
cfg80211_wiphy_work+0x225/0x260 net/wireless/core.c:437
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792

kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>

---
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