[v6.1] possible deadlock in hid_hw_open

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f6e38ae624cf Linux 6.1.158
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=15c748b4580000
kernel config: https://syzkaller.appspot.com/x/.config?x=7eb38bd5021fec61
dashboard link: https://syzkaller.appspot.com/bug?extid=5b561352f6fb49fc5a88
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/2b7003e2661d/disk-f6e38ae6.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0696cea8d016/vmlinux-f6e38ae6.xz
kernel image: https://storage.googleapis.com/syzbot-assets/6b7a89e636d7/bzImage-f6e38ae6.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5b5613...@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
acpid/3622 is trying to acquire lock:
ffff88802b7a1e18 (&hdev->ll_open_lock){+.+.}-{3:3}, at: hid_hw_open+0x23/0x160 drivers/hid/hid-core.c:2347

but task is already holding lock:
ffff888141a932c0 (&dev->mutex#2){+.+.}-{3:3}, at: input_open_device+0x4e/0x2e0 drivers/input/input.c:630

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&dev->mutex#2){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
input_disconnect_device drivers/input/input.c:757 [inline]
__input_unregister_device+0x31/0x5f0 drivers/input/input.c:2291
input_unregister_device+0x97/0xf0 drivers/input/input.c:2514
steam_client_ll_open+0x73/0x90 drivers/hid/hid-steam.c:640
hid_hw_open+0xdd/0x160 drivers/hid/hid-core.c:2352
hidraw_open+0x28d/0x8a0 drivers/hid/hidraw.c:294
chrdev_open+0x597/0x670 fs/char_dev.c:414
do_dentry_open+0x7e9/0x10d0 fs/open.c:882
do_open fs/namei.c:3634 [inline]
path_openat+0x25c6/0x2e70 fs/namei.c:3791
do_filp_open+0x1c1/0x3c0 fs/namei.c:3818
do_sys_openat2+0x142/0x490 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]
__x64_sys_openat+0x135/0x160 fs/open.c:1345
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&hdev->ll_open_lock){+.+.}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3090 [inline]
check_prevs_add kernel/locking/lockdep.c:3209 [inline]
validate_chain kernel/locking/lockdep.c:3825 [inline]
__lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
hid_hw_open+0x23/0x160 drivers/hid/hid-core.c:2347
input_open_device+0x16c/0x2e0 drivers/input/input.c:650
evdev_open_device drivers/input/evdev.c:400 [inline]
evdev_open+0x4b0/0x5b0 drivers/input/evdev.c:487
chrdev_open+0x597/0x670 fs/char_dev.c:414
do_dentry_open+0x7e9/0x10d0 fs/open.c:882
do_open fs/namei.c:3634 [inline]
path_openat+0x25c6/0x2e70 fs/namei.c:3791
do_filp_open+0x1c1/0x3c0 fs/namei.c:3818
do_sys_openat2+0x142/0x490 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]
__x64_sys_openat+0x135/0x160 fs/open.c:1345
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&dev->mutex#2);
lock(&hdev->ll_open_lock);
lock(&dev->mutex#2);
lock(&hdev->ll_open_lock);

*** DEADLOCK ***

2 locks held by acpid/3622:
#0: ffff888141a95110 (&evdev->mutex){+.+.}-{3:3}, at: evdev_open_device drivers/input/evdev.c:393 [inline]
#0: ffff888141a95110 (&evdev->mutex){+.+.}-{3:3}, at: evdev_open+0x2d2/0x5b0 drivers/input/evdev.c:487
#1: ffff888141a932c0 (&dev->mutex#2){+.+.}-{3:3}, at: input_open_device+0x4e/0x2e0 drivers/input/input.c:630

stack backtrace:
CPU: 0 PID: 3622 Comm: acpid Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
<TASK>
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2170
check_prev_add kernel/locking/lockdep.c:3090 [inline]
check_prevs_add kernel/locking/lockdep.c:3209 [inline]
validate_chain kernel/locking/lockdep.c:3825 [inline]
__lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x120/0xaf0 kernel/locking/mutex.c:747
hid_hw_open+0x23/0x160 drivers/hid/hid-core.c:2347
input_open_device+0x16c/0x2e0 drivers/input/input.c:650
evdev_open_device drivers/input/evdev.c:400 [inline]
evdev_open+0x4b0/0x5b0 drivers/input/evdev.c:487
chrdev_open+0x597/0x670 fs/char_dev.c:414
do_dentry_open+0x7e9/0x10d0 fs/open.c:882
do_open fs/namei.c:3634 [inline]
path_openat+0x25c6/0x2e70 fs/namei.c:3791
do_filp_open+0x1c1/0x3c0 fs/namei.c:3818
do_sys_openat2+0x142/0x490 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]
__x64_sys_openat+0x135/0x160 fs/open.c:1345
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fd2550cb407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fff0af11f00 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fd255041740 RCX: 00007fd2550cb407
RDX: 0000000000080800 RSI: 00007fff0af12110 RDI: ffffffffffffff9c
RBP: 00007fff0af12110 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000020
R13: 00007fff0af12210 R14: 0000561046ac47fe R15: 00007fff0af12210
</TASK>


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