CVE-2026-63947

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

Bluetooth: HIDP: fix missing length checks in hidp_input_report()

hidp_input_report() reads keyboard and mouse payload data from an skb without first verifying that skb->len contains enough data.

hidp_recv_intr_frame() pulls the 1-byte HIDP header before dispatching to hidp_input_report(). If a paired device sends a truncated packet, the handler reads beyond the valid skb data, resulting in an out-of-bounds read of skb data. The OOB bytes may be interpreted as phantom key presses or spurious mouse movement.

Replace the open-coded length tracking and pointer arithmetic with skb_pull_data() calls. skb_pull_data() returns NULL if the requested bytes are not present, eliminating the need for a manual size variable and the separate skb->len guard.

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
• To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/540.html

References

• https://git.kernel.org/stable/c/1f08a90013e1e632b34321334e861fcefc056505
• https://git.kernel.org/stable/c/2a3ac9ee11dbb9845f3947cef4a79dba658cf6f6
• https://git.kernel.org/stable/c/6348dfed5b0f9c6074f14322332e97493d32fef0
• https://git.kernel.org/stable/c/b83dcacd2ec7fcc5a48be215f82d573759f87ec2
• https://git.kernel.org/stable/c/cc3832b19f863e3677c5651f001a2e3795f39eb8
• https://git.kernel.org/stable/c/d313683d6ccdd8c01e0562270a2ae25b86d8461d
• https://git.kernel.org/stable/c/d7d6a81b8dd1a8d084a1b755db9406041d53adb5