syzbot


possible deadlock in hid_hw_open (2)

Status: upstream: reported on 2025/07/23 06:50
Reported-by: syzbot+59be4801ca23ec452bf4@syzkaller.appspotmail.com
First crash: 17h48m, last: 17h48m
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 possible deadlock in hid_hw_open 4 1 109d 109d 0/3 auto-obsoleted due to no activity on 2025/07/15 00:10
upstream possible deadlock in hid_hw_open input 4 73 169d 339d 0/29 auto-obsoleted due to no activity on 2025/04/15 13:39

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
5.15.189-syzkaller #0 Not tainted
------------------------------------------------------
acpid/3546 is trying to acquire lock:
ffff888054535ee0 (&hdev->ll_open_lock){+.+.}-{3:3}, at: hid_hw_open+0x23/0x160 drivers/hid/hid-core.c:2118

but task is already holding lock:
ffff8880539be2c0 (&dev->mutex#2){+.+.}-{3:3}, at: input_open_device+0x4e/0x2e0 drivers/input/input.c:620

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&dev->mutex#2){+.+.}-{3:3}:
       __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_interruptible_nested+0x17/0x20 kernel/locking/mutex.c:765
       input_register_handle+0x67/0x3a0 drivers/input/input.c:2588
       kbd_connect+0xbf/0x130 drivers/tty/vt/keyboard.c:1577
       input_attach_handler drivers/input/input.c:1046 [inline]
       input_register_device+0xda7/0x1140 drivers/input/input.c:2429
       acpi_button_add+0x6ba/0xae0 drivers/acpi/button.c:579
       acpi_device_probe+0xa3/0x300 drivers/acpi/bus.c:1013
       call_driver_probe drivers/base/dd.c:-1 [inline]
       really_probe+0x284/0xc80 drivers/base/dd.c:595
       __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755
       driver_probe_device+0x4f/0x420 drivers/base/dd.c:785
       __driver_attach+0x46b/0x670 drivers/base/dd.c:1164
       bus_for_each_dev+0x175/0x1e0 drivers/base/bus.c:303
       bus_add_driver+0x30a/0x5a0 drivers/base/bus.c:620
       driver_register+0x32d/0x430 drivers/base/driver.c:240
       do_one_initcall+0x1ee/0x680 init/main.c:1302
       do_initcall_level+0x137/0x1f0 init/main.c:1375
       do_initcalls+0x4b/0x90 init/main.c:1391
       kernel_init_freeable+0x3ce/0x560 init/main.c:1615
       kernel_init+0x19/0x1b0 init/main.c:1506
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

-> #1 (input_mutex){+.+.}-{3:3}:
       __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_interruptible_nested+0x17/0x20 kernel/locking/mutex.c:765
       input_register_device+0xb66/0x1140 drivers/input/input.c:2422
       steam_input_register+0x9b1/0xc80 drivers/hid/hid-steam.c:469
       hid_hw_close+0xa5/0xd0 drivers/hid/hid-core.c:2146
       drop_ref drivers/hid/hidraw.c:338 [inline]
       hidraw_release+0x39d/0x5d0 drivers/hid/hidraw.c:360
       __fput+0x234/0x930 fs/file_table.c:311
       task_work_run+0x125/0x1a0 kernel/task_work.c:188
       tracehook_notify_resume include/linux/tracehook.h:189 [inline]
       exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
       exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
       __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
       syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
       do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #0 (&hdev->ll_open_lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain kernel/locking/lockdep.c:3788 [inline]
       __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
       lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
       __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
       __mutex_lock kernel/locking/mutex.c:729 [inline]
       mutex_lock_killable_nested+0x17/0x20 kernel/locking/mutex.c:758
       hid_hw_open+0x23/0x160 drivers/hid/hid-core.c:2118
       input_open_device+0x16c/0x2e0 drivers/input/input.c:640
       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+0x7ff/0xf80 fs/open.c:826
       do_open fs/namei.c:3608 [inline]
       path_openat+0x2682/0x2f30 fs/namei.c:3742
       do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
       do_sys_openat2+0x142/0x4a0 fs/open.c:1253
       do_sys_open fs/open.c:1269 [inline]
       __do_sys_openat fs/open.c:1285 [inline]
       __se_sys_openat fs/open.c:1280 [inline]
       __x64_sys_openat+0x135/0x160 fs/open.c:1280
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

Chain exists of:
  &hdev->ll_open_lock --> input_mutex --> &dev->mutex#2

 Possible unsafe locking scenario:

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

 *** DEADLOCK ***

2 locks held by acpid/3546:
 #0: ffff88807846e110 (&evdev->mutex){+.+.}-{3:3}, at: evdev_open_device drivers/input/evdev.c:393 [inline]
 #0: ffff88807846e110 (&evdev->mutex){+.+.}-{3:3}, at: evdev_open+0x2d2/0x5b0 drivers/input/evdev.c:487
 #1: ffff8880539be2c0 (&dev->mutex#2){+.+.}-{3:3}, at: input_open_device+0x4e/0x2e0 drivers/input/input.c:620

stack backtrace:
CPU: 1 PID: 3546 Comm: acpid Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 check_noncircular+0x274/0x310 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain kernel/locking/lockdep.c:3788 [inline]
 __lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
 lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
 __mutex_lock_common+0x1eb/0x2390 kernel/locking/mutex.c:596
 __mutex_lock kernel/locking/mutex.c:729 [inline]
 mutex_lock_killable_nested+0x17/0x20 kernel/locking/mutex.c:758
 hid_hw_open+0x23/0x160 drivers/hid/hid-core.c:2118
 input_open_device+0x16c/0x2e0 drivers/input/input.c:640
 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+0x7ff/0xf80 fs/open.c:826
 do_open fs/namei.c:3608 [inline]
 path_openat+0x2682/0x2f30 fs/namei.c:3742
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
 do_sys_openat2+0x142/0x4a0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1280
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f8f71dcf407
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:00007ffd2fe08800 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f8f71d45740 RCX: 00007f8f71dcf407
RDX: 0000000000080800 RSI: 00007ffd2fe08a10 RDI: ffffffffffffff9c
RBP: 00007ffd2fe08a10 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000040
R13: 00007ffd2fe08b10 R14: 0000560a4a0ef7fe R15: 00007ffd2fe08b10
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/07/23 06:50 linux-5.15.y c79648372d02 e1dd4f22 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan possible deadlock in hid_hw_open
* Struck through repros no longer work on HEAD.