CVE-2025-38394
Linux HID: Uninitialized Free Pointer (UAF)
Description
In the Linux kernel, the following vulnerability has been resolved: HID: appletb-kbd: fix memory corruption of input_handler_list In appletb_kbd_probe an input handler is initialised and then registered with input core through input_register_handler(). When this happens input core will add the input handler (specifically its node) to the global input_handler_list. The input_handler_list is central to the functionality of input core and is traversed in various places in input core. An example of this is when a new input device is plugged in and gets registered with input core. The input_handler in probe is allocated as device managed memory. If a probe failure occurs after input_register_handler() the input_handler memory is freed, yet it will remain in the input_handler_list. This effectively means the input_handler_list contains a dangling pointer to data belonging to a freed input handler. This causes an issue when any other input device is plugged in - in my case I had an old PixArt HP USB optical mouse and I decided to plug it in after a failure occurred after input_register_handler(). This lead to the registration of this input device via input_register_device which involves traversing over every handler in the corrupted input_handler_list and calling input_attach_handler(), giving each handler a chance to bind to newly registered device. The core of this bug is a UAF which causes memory corruption of input_handler_list and to fix it we must ensure the input handler is unregistered from input core, this is done through input_unregister_handler(). [ 63.191597] ================================================================== [ 63.192094] BUG: KASAN: slab-use-after-free in input_attach_handler.isra.0+0x1a9/0x1e0 [ 63.192094] Read of size 8 at addr ffff888105ea7c80 by task kworker/0:2/54 [ 63.192094] [ 63.192094] CPU: 0 UID: 0 PID: 54 Comm: kworker/0:2 Not tainted 6.16.0-rc2-00321-g2aa6621d [ 63.192094] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.164 [ 63.192094] Workqueue: usb_hub_wq hub_event [ 63.192094] Call Trace: [ 63.192094] <TASK> [ 63.192094] dump_stack_lvl+0x53/0x70 [ 63.192094] print_report+0xce/0x670 [ 63.192094] kasan_report+0xce/0x100 [ 63.192094] input_attach_handler.isra.0+0x1a9/0x1e0 [ 63.192094] input_register_device+0x76c/0xd00 [ 63.192094] hidinput_connect+0x686d/0xad60 [ 63.192094] hid_connect+0xf20/0x1b10 [ 63.192094] hid_hw_start+0x83/0x100 [ 63.192094] hid_device_probe+0x2d1/0x680 [ 63.192094] really_probe+0x1c3/0x690 [ 63.192094] __driver_probe_device+0x247/0x300 [ 63.192094] driver_probe_device+0x49/0x210 [ 63.192094] __device_attach_driver+0x160/0x320 [ 63.192094] bus_for_each_drv+0x10f/0x190 [ 63.192094] __device_attach+0x18e/0x370 [ 63.192094] bus_probe_device+0x123/0x170 [ 63.192094] device_add+0xd4d/0x1460 [ 63.192094] hid_add_device+0x30b/0x910 [ 63.192094] usbhid_probe+0x920/0xe00 [ 63.192094] usb_probe_interface+0x363/0x9a0 [ 63.192094] really_probe+0x1c3/0x690 [ 63.192094] __driver_probe_device+0x247/0x300 [ 63.192094] driver_probe_device+0x49/0x210 [ 63.192094] __device_attach_driver+0x160/0x320 [ 63.192094] bus_for_each_drv+0x10f/0x190 [ 63.192094] __device_attach+0x18e/0x370 [ 63.192094] bus_probe_device+0x123/0x170 [ 63.192094] device_add+0xd4d/0x1460 [ 63.192094] usb_set_configuration+0xd14/0x1880 [ 63.192094] usb_generic_driver_probe+0x78/0xb0 [ 63.192094] usb_probe_device+0xaa/0x2e0 [ 63.192094] really_probe+0x1c3/0x690 [ 63.192094] __driver_probe_device+0x247/0x300 [ 63.192094] driver_probe_device+0x49/0x210 [ 63.192094] __device_attach_driver+0x160/0x320 [ 63.192094] bus_for_each_drv+0x10f/0x190 [ 63.192094] __device_attach+0x18e/0x370 [ 63.192094] bus_probe_device+0x123/0x170 [ 63.192094] device_add+0xd4d/0x1460 [ 63.192094] usb_new_device+0x7b4/0x1000 [ 63.192094] hub_event+0x234d/0x3 ---truncated---
INFO
Published Date :
July 25, 2025, 1:15 p.m.
Last Modified :
July 25, 2025, 3:29 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Solution
- There is no known solution at this time.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-38394.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/6ad40b07e15c29712d9a4b8096914ccd82e3fc17 | |
| https://git.kernel.org/stable/c/c80f2b047d5cc42fbd2dff9d1942d4ba7545100f |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-38394 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-38394
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-38394 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-38394 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 25, 2025
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: HID: appletb-kbd: fix memory corruption of input_handler_list In appletb_kbd_probe an input handler is initialised and then registered with input core through input_register_handler(). When this happens input core will add the input handler (specifically its node) to the global input_handler_list. The input_handler_list is central to the functionality of input core and is traversed in various places in input core. An example of this is when a new input device is plugged in and gets registered with input core. The input_handler in probe is allocated as device managed memory. If a probe failure occurs after input_register_handler() the input_handler memory is freed, yet it will remain in the input_handler_list. This effectively means the input_handler_list contains a dangling pointer to data belonging to a freed input handler. This causes an issue when any other input device is plugged in - in my case I had an old PixArt HP USB optical mouse and I decided to plug it in after a failure occurred after input_register_handler(). This lead to the registration of this input device via input_register_device which involves traversing over every handler in the corrupted input_handler_list and calling input_attach_handler(), giving each handler a chance to bind to newly registered device. The core of this bug is a UAF which causes memory corruption of input_handler_list and to fix it we must ensure the input handler is unregistered from input core, this is done through input_unregister_handler(). [ 63.191597] ================================================================== [ 63.192094] BUG: KASAN: slab-use-after-free in input_attach_handler.isra.0+0x1a9/0x1e0 [ 63.192094] Read of size 8 at addr ffff888105ea7c80 by task kworker/0:2/54 [ 63.192094] [ 63.192094] CPU: 0 UID: 0 PID: 54 Comm: kworker/0:2 Not tainted 6.16.0-rc2-00321-g2aa6621d [ 63.192094] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.164 [ 63.192094] Workqueue: usb_hub_wq hub_event [ 63.192094] Call Trace: [ 63.192094] <TASK> [ 63.192094] dump_stack_lvl+0x53/0x70 [ 63.192094] print_report+0xce/0x670 [ 63.192094] kasan_report+0xce/0x100 [ 63.192094] input_attach_handler.isra.0+0x1a9/0x1e0 [ 63.192094] input_register_device+0x76c/0xd00 [ 63.192094] hidinput_connect+0x686d/0xad60 [ 63.192094] hid_connect+0xf20/0x1b10 [ 63.192094] hid_hw_start+0x83/0x100 [ 63.192094] hid_device_probe+0x2d1/0x680 [ 63.192094] really_probe+0x1c3/0x690 [ 63.192094] __driver_probe_device+0x247/0x300 [ 63.192094] driver_probe_device+0x49/0x210 [ 63.192094] __device_attach_driver+0x160/0x320 [ 63.192094] bus_for_each_drv+0x10f/0x190 [ 63.192094] __device_attach+0x18e/0x370 [ 63.192094] bus_probe_device+0x123/0x170 [ 63.192094] device_add+0xd4d/0x1460 [ 63.192094] hid_add_device+0x30b/0x910 [ 63.192094] usbhid_probe+0x920/0xe00 [ 63.192094] usb_probe_interface+0x363/0x9a0 [ 63.192094] really_probe+0x1c3/0x690 [ 63.192094] __driver_probe_device+0x247/0x300 [ 63.192094] driver_probe_device+0x49/0x210 [ 63.192094] __device_attach_driver+0x160/0x320 [ 63.192094] bus_for_each_drv+0x10f/0x190 [ 63.192094] __device_attach+0x18e/0x370 [ 63.192094] bus_probe_device+0x123/0x170 [ 63.192094] device_add+0xd4d/0x1460 [ 63.192094] usb_set_configuration+0xd14/0x1880 [ 63.192094] usb_generic_driver_probe+0x78/0xb0 [ 63.192094] usb_probe_device+0xaa/0x2e0 [ 63.192094] really_probe+0x1c3/0x690 [ 63.192094] __driver_probe_device+0x247/0x300 [ 63.192094] driver_probe_device+0x49/0x210 [ 63.192094] __device_attach_driver+0x160/0x320 [ 63.192094] bus_for_each_drv+0x10f/0x190 [ 63.192094] __device_attach+0x18e/0x370 [ 63.192094] bus_probe_device+0x123/0x170 [ 63.192094] device_add+0xd4d/0x1460 [ 63.192094] usb_new_device+0x7b4/0x1000 [ 63.192094] hub_event+0x234d/0x3 ---truncated--- Added Reference https://git.kernel.org/stable/c/6ad40b07e15c29712d9a4b8096914ccd82e3fc17 Added Reference https://git.kernel.org/stable/c/c80f2b047d5cc42fbd2dff9d1942d4ba7545100f