[v6.1] INFO: task hung in do_renameat2

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 883d1a956208 Linux 6.1.75
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=161157a7e80000
kernel config: https://syzkaller.appspot.com/x/.config?x=c421ffef554bdd17
dashboard link: https://syzkaller.appspot.com/bug?extid=8aebd3fa24fb1521f74d
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/1ff30edbe66d/disk-883d1a95.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1cd87be79a04/vmlinux-883d1a95.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e50c5a26cded/Image-883d1a95.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8aebd3...@syzkaller.appspotmail.com

INFO: task syz-executor.4:20356 blocked for more than 143 seconds.
Not tainted 6.1.75-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.4 state:D stack:0 pid:20356 ppid:4267 flags:0x00000005
Call trace:
__switch_to+0x320/0x754 arch/arm64/kernel/process.c:553
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0xee4/0x1c98 kernel/sched/core.c:6558
schedule+0xc4/0x170 kernel/sched/core.c:6634
rwsem_down_write_slowpath+0xc80/0x156c kernel/locking/rwsem.c:1189
__down_write_common kernel/locking/rwsem.c:1314 [inline]
__down_write kernel/locking/rwsem.c:1323 [inline]
down_write_nested+0x90/0x94 kernel/locking/rwsem.c:1690
inode_lock_nested include/linux/fs.h:791 [inline]
lock_rename fs/namei.c:3042 [inline]
do_renameat2+0x4e0/0xe34 fs/namei.c:4954
__do_sys_renameat fs/namei.c:5055 [inline]
__se_sys_renameat fs/namei.c:5052 [inline]
__arm64_sys_renameat+0xc8/0xe4 fs/namei.c:5052
__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:142
do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
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: ffff800015a04eb0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:516
1 lock held by rcu_tasks_trace/13:
#0: ffff800015a056b0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x44/0xcf4 kernel/rcu/tasks.h:516
1 lock held by khungtaskd/28:
#0: ffff800015a04ce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0xc/0x44 include/linux/rcupdate.h:317
2 locks held by getty/3981:
#0: ffff0000d8040098 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3c/0x4c drivers/tty/tty_ldsem.c:340
#1: ffff80001bcc02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x414/0x1214 drivers/tty/n_tty.c:2188
2 locks held by syz-executor.4/20356:
#0: ffff0000cedcc460 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x44/0x9c fs/namespace.c:393
#1: ffff000122d11cb0 (&sb->s_type->i_mutex_key#23/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:791 [inline]
#1: ffff000122d11cb0 (&sb->s_type->i_mutex_key#23/1){+.+.}-{3:3}, at: lock_rename fs/namei.c:3042 [inline]
#1: ffff000122d11cb0 (&sb->s_type->i_mutex_key#23/1){+.+.}-{3:3}, at: do_renameat2+0x4e0/0xe34 fs/namei.c:4954
3 locks held by syz-executor.4/20362:
2 locks held by syz-executor.4/20700:
3 locks held by kworker/u4:19/23406:
2 locks held by kworker/u4:21/23411:
2 locks held by kworker/u4:25/23663:
#0: ffff0000c0029138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x664/0x1404 kernel/workqueue.c:2265
#1: ffff80002a8c7c20 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work+0x6a8/0x1404 kernel/workqueue.c:2267
2 locks held by syz-executor.0/26936:

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



---
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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 284087d4f7d5 Linux 5.15.158
git tree: linux-5.15.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1194f600980000
kernel config: https://syzkaller.appspot.com/x/.config?x=b0dd54e4b5171ebc
dashboard link: https://syzkaller.appspot.com/bug?extid=639adcbeb2636be0d940

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/c2e33c1db6bf/disk-284087d4.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/d9f77284af1d/vmlinux-284087d4.xz
kernel image: https://storage.googleapis.com/syzbot-assets/a600323dd149/bzImage-284087d4.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:

Reported-by: syzbot+639adc...@syzkaller.appspotmail.com

INFO: task syz-executor.3:7509 blocked for more than 144 seconds.
Not tainted 5.15.158-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:syz-executor.3 state:D stack:23008 pid: 7509 ppid: 4240 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
schedule+0x11b/0x1f0 kernel/sched/core.c:6459
rwsem_down_write_slowpath+0xf0c/0x16a0 kernel/locking/rwsem.c:1165
do_renameat2+0x67e/0x1700 fs/namei.c:4924
__do_sys_renameat2 fs/namei.c:5018 [inline]
__se_sys_renameat2 fs/namei.c:5015 [inline]
__x64_sys_renameat2+0xce/0xe0 fs/namei.c:5015
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f99d5b63d69
RSP: 002b:00007f99d40b50c8 EFLAGS: 00000246 ORIG_RAX: 000000000000013c
RAX: ffffffffffffffda RBX: 00007f99d5c92050 RCX: 00007f99d5b63d69
RDX: 0000000000000009 RSI: 0000000020000240 RDI: 0000000000000009
RBP: 00007f99d5bb049e R08: 0000000000000002 R09: 0000000000000000
R10: 00000000200001c0 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f99d5c92050 R15: 00007ffe77f9fb88
</TASK>
INFO: task syz-executor.3:7518 blocked for more than 145 seconds.
Not tainted 5.15.158-syzkaller #0

"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

task:syz-executor.3 state:D stack:27584 pid: 7518 ppid: 4240 flags:0x00004006
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
schedule+0x11b/0x1f0 kernel/sched/core.c:6459
rwsem_down_write_slowpath+0xf0c/0x16a0 kernel/locking/rwsem.c:1165
inode_lock include/linux/fs.h:789 [inline]
open_last_lookups fs/namei.c:3529 [inline]
path_openat+0x824/0x2f20 fs/namei.c:3739
do_filp_open+0x21c/0x460 fs/namei.c:3769
do_sys_openat2+0x13b/0x500 fs/open.c:1253
do_sys_open fs/open.c:1269 [inline]
__do_sys_open fs/open.c:1277 [inline]
__se_sys_open fs/open.c:1273 [inline]
__x64_sys_open+0x221/0x270 fs/open.c:1273
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f99d5b63d69
RSP: 002b:00007f99d40730c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f99d5c921f0 RCX: 00007f99d5b63d69
RDX: 0000000000000000 RSI: 000000000014507e RDI: 0000000020000200
RBP: 00007f99d5bb049e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000006e R14: 00007f99d5c921f0 R15: 00007ffe77f9fb88
</TASK>

Showing all locks held in the system:

1 lock held by khungtaskd/27:
#0: ffffffff8c91fae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
2 locks held by getty/3262:
#0: ffff888024503098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
#1: ffffc9000209b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6af/0x1db0 drivers/tty/n_tty.c:2158
2 locks held by kworker/1:16/4029:
#0: ffff888011c72138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
#1: ffffc90004447d20 ((work_completion)(&rew.rew_work)){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
4 locks held by kworker/u4:11/4103:
#0: ffff888011dcd138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x78a/0x10c0 kernel/workqueue.c:2283
#1: ffffc9000132fd20 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7d0/0x10c0 kernel/workqueue.c:2285
#2: ffffffff8d9dbf50 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0xf1/0xb60 net/core/net_namespace.c:558
#3: ffffffff8c923fb0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x9c/0x4e0 kernel/rcu/tree.c:4039
3 locks held by syz-executor.3/7482:
2 locks held by syz-executor.3/7509:
#0: ffff88807b83c460 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:377
#1: ffff88805acd4188 (&type->i_mutex_dir_key#17/1){+.+.}-{3:3}, at: do_renameat2+0x67e/0x1700 fs/namei.c:4924
2 locks held by syz-executor.3/7518:
#0: ffff88807b83c460 (sb_writers#23){.+.+}-{0:0}, at: mnt_want_write+0x3b/0x80 fs/namespace.c:377
#1: ffff88805acd4188 (&type->i_mutex_dir_key#17){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
#1: ffff88805acd4188 (&type->i_mutex_dir_key#17){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3529 [inline]
#1: ffff88805acd4188 (&type->i_mutex_dir_key#17){+.+.}-{3:3}, at: path_openat+0x824/0x2f20 fs/namei.c:3739
2 locks held by syz-executor.0/9574:
#0: ffffffff8d9e7b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d9e7b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626
#1: ffffffff8c9240a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
#1: ffffffff8c9240a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x280/0x740 kernel/rcu/tree_exp.h:845
1 lock held by syz-executor.2/9578:
#0: ffffffff8d9e7b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
#0: ffffffff8d9e7b08 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x94c/0xee0 net/core/rtnetlink.c:5626
2 locks held by syz-executor.4/9589:
#0: ffff88801b4f6118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0xfb/0x790 block/bdev.c:912
#1: ffff88801b4af468 (&lo->lo_mutex){+.+.}-{3:3}, at: lo_release+0x4d/0x1f0 drivers/block/loop.c:2070
2 locks held by syz-executor.1/9591:
#0: ffff88807f0658b8 (&nft_net->commit_mutex){+.+.}-{3:3}, at: nf_tables_valid_genid+0x27/0xa0 net/netfilter/nf_tables_api.c:9943
#1: ffffffff8c9240a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:322 [inline]
#1: ffffffff8c9240a8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x350/0x740 kernel/rcu/tree_exp.h:845
1 lock held by syz-executor.1/9594:
#0: ffffffff8d9e7b08 (rtnl_mutex){+.+.}-{3:3}, at: __tun_chr_ioctl+0x460/0x2270 drivers/net/tun.c:3049
1 lock held by syz-executor.3/9596:
#0: ffff88804bd8dc10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:789 [inline]
#0: ffff88804bd8dc10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: __sock_release net/socket.c:648 [inline]
#0: ffff88804bd8dc10 (&sb->s_type->i_mutex_key#11){+.+.}-{3:3}, at: sock_close+0x98/0x230 net/socket.c:1336

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

NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.158-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:210 [inline]
watchdog+0xe72/0xeb0 kernel/hung_task.c:295
kthread+0x3f6/0x4f0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3749 Comm: kworker/u4:7 Not tainted 5.15.158-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
Workqueue: bat_events batadv_nc_worker
RIP: 0010:rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline]
RIP: 0010:rcu_is_watching+0x31/0xa0 kernel/rcu/tree.c:1123
Code: 05 6c 5b 97 7e e8 ff cc b2 08 89 c3 83 f8 08 73 72 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 00 e8 35 8c 4c 89 f0 48 c1 e8 03 <42> 80 3c 38 00 74 08 4c 89 f7 e8 50 20 5f 00 48 c7 c3 08 b3 03 00
RSP: 0018:ffffc900040c7aa0 EFLAGS: 00000a02
RAX: 1ffffffff186bd01 RBX: 0000000000000001 RCX: ffffffff8162d268
RDX: 0000000000000000 RSI: ffffffff8ad8f5e0 RDI: ffffffff8ad8f5a0
RBP: ffffc900040c7be8 R08: dffffc0000000000 R09: fffffbfff1bc8c56
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000818f64
R13: ffffffff89fb9c75 R14: ffffffff8c35e808 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f647087a978 CR3: 000000002330e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<NMI>
</NMI>
<TASK>
trace_lock_release include/trace/events/lock.h:58 [inline]
lock_release+0xb9/0x9a0 kernel/locking/lockdep.c:5634
rcu_read_unlock include/linux/rcupdate.h:772 [inline]
batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline]
batadv_nc_worker+0x239/0x5b0 net/batman-adv/network-coding.c:723
process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
kthread+0x3f6/0x4f0 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:300
</TASK>