CVE-2025-38016
Unknown Unknown - Not Provided
BaseFortify

Publication date: 2025-06-18

Last updated on: 2025-11-14

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: HID: bpf: abort dispatch if device destroyed The current HID bpf implementation assumes no output report/request will go through it after hid_bpf_destroy_device() has been called. This leads to a bug that unplugging certain types of HID devices causes a cleaned- up SRCU to be accessed. The bug was previously a hidden failure until a recent x86 percpu change [1] made it access not-present pages. The bug will be triggered if the conditions below are met: A) a device under the driver has some LEDs on B) hid_ll_driver->request() is uninplemented (e.g., logitech-djreceiver) If condition A is met, hidinput_led_worker() is always scheduled *after* hid_bpf_destroy_device(). hid_destroy_device ` hid_bpf_destroy_device ` cleanup_srcu_struct(&hdev->bpf.srcu) ` hid_remove_device ` ... ` led_classdev_unregister ` led_trigger_set(led_cdev, NULL) ` led_set_brightness(led_cdev, LED_OFF) ` ... ` input_inject_event ` input_event_dispose ` hidinput_input_event ` schedule_work(&hid->led_work) [hidinput_led_worker] This is fine when condition B is not met, where hidinput_led_worker() calls hid_ll_driver->request(). This is the case for most HID drivers, which implement it or use the generic one from usbhid. The driver itself or an underlying driver will then abort processing the request. Otherwise, hidinput_led_worker() tries hid_hw_output_report() and leads to the bug. hidinput_led_worker ` hid_hw_output_report ` dispatch_hid_bpf_output_report ` srcu_read_lock(&hdev->bpf.srcu) ` srcu_read_unlock(&hdev->bpf.srcu, idx) The bug has existed since the introduction [2] of dispatch_hid_bpf_output_report(). However, the same bug also exists in dispatch_hid_bpf_raw_requests(), and I've reproduced (no visible effect because of the lack of [1], but confirmed bpf.destroyed == 1) the bug against the commit (i.e., the Fixes:) introducing the function. This is because hidinput_led_worker() falls back to hid_hw_raw_request() when hid_ll_driver->output_report() is uninplemented (e.g., logitech- djreceiver). hidinput_led_worker ` hid_hw_output_report: -ENOSYS ` hid_hw_raw_request ` dispatch_hid_bpf_raw_requests ` srcu_read_lock(&hdev->bpf.srcu) ` srcu_read_unlock(&hdev->bpf.srcu, idx) Fix the issue by returning early in the two mentioned functions if hid_bpf has been marked as destroyed. Though dispatch_hid_bpf_device_event() handles input events, and there is no evidence that it may be called after the destruction, the same check, as a safety net, is also added to it to maintain the consistency among all dispatch functions. The impact of the bug on other architectures is unclear. Even if it acts as a hidden failure, this is still dangerous because it corrupts whatever is on the address calculated by SRCU. Thus, CC'ing the stable list. [1]: commit 9d7de2aa8b41 ("x86/percpu/64: Use relative percpu offsets") [2]: commit 9286675a2aed ("HID: bpf: add HID-BPF hooks for hid_hw_output_report")
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Meta Information
Published
2025-06-18
Last Modified
2025-11-14
Generated
2026-05-07
AI Q&A
2025-06-18
EPSS Evaluated
2026-05-05
NVD
CVE-2025-38016
Affected Vendors & Products
Showing 8 associated CPEs
Vendor Product Version / Range
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
linux linux_kernel 6.15
linux linux_kernel 6.15
linux linux_kernel 6.15
linux linux_kernel 6.15
linux linux_kernel 6.15
linux linux_kernel 6.15
linux linux_kernel From 5.15.160 (inc) to 5.16 (inc)
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CWE ID Description
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AI Powered Q&A
Can you explain this vulnerability to me?

This vulnerability exists in the Linux kernel's HID bpf implementation. It occurs because the code assumes no output report or request will be processed after the device has been destroyed via hid_bpf_destroy_device(). However, if certain conditions are met—specifically, if a device has LEDs on and the driver does not implement the request() function—then after the device is destroyed, a scheduled worker (hidinput_led_worker) still tries to send output reports. This leads to accessing a cleaned-up SRCU structure, causing a bug that can corrupt memory or cause failures. The issue arises from the way the HID bpf dispatch functions handle requests after device destruction, and it was fixed by adding checks to return early if the device is marked as destroyed.


How can this vulnerability impact me? :

This vulnerability can cause memory corruption or access to invalid memory areas in the Linux kernel when certain HID devices are unplugged. This can lead to system instability, crashes, or potentially exploitable conditions depending on the environment. The bug is triggered when devices with LEDs and uninplemented request() functions are removed, causing the kernel to access cleaned-up SRCU structures. Although the impact on architectures other than x86 is unclear, it is considered dangerous because it corrupts memory.


What immediate steps should I take to mitigate this vulnerability?

To mitigate this vulnerability, update the Linux kernel to a version that includes the fix which returns early in dispatch_hid_bpf_output_report() and dispatch_hid_bpf_raw_requests() if the hid_bpf device has been marked as destroyed. This prevents accessing cleaned-up SRCU structures after device removal. Avoid unplugging affected HID devices until the patch is applied.


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