CVE-2025-21923

In the Linux kernel, the following vulnerability has been resolved:

HID: hid-steam: Fix use-after-free when detaching device

When a hid-steam device is removed it must clean up the client_hdev used for intercepting hidraw access. This can lead to scheduling deferred work to reattach the input device. Though the cleanup cancels the deferred work, this was done before the client_hdev itself is cleaned up, so it gets rescheduled. This patch fixes the ordering to make sure the deferred work is properly canceled.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/026714ec7546de741826324a6a1914c91024d06c
• https://git.kernel.org/stable/c/a899adf7063c6745aaff1ec869f3c7f6329ed0a1
• https://git.kernel.org/stable/c/e53fc232a65f7488ab75d03a5b95f06aaada7262
• https://git.kernel.org/stable/c/ea3f18d2f02629653b7bfe42607737ccd1343e54