CVE-2026-64299

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

tracing: Prevent out-of-bounds read in glob matching

String event fields are not necessarily NUL-terminated, so the filter predicate functions (filter_pred_string(), filter_pred_strloc() and filter_pred_strrelloc()) pass the field length to the regex match callbacks, and the length-aware matchers honour it.

regex_match_glob() was the exception: it ignored the length and called glob_match(), which scans the string until it hits a NUL byte. Some string fields are not NUL-terminated. One example is the dynamic char array of the xfs_* namespace tracepoints, which is copied without a trailing NUL. For such a field, glob matching reads past the end of the event field, causing a KASAN slab-out-of-bounds read in glob_match(), reached via regex_match_glob() and filter_match_preds() from the xfs_lookup tracepoint.

Add a length-bounded glob_match_len() and use it from regex_match_glob() so glob matching always stops at the field boundary. The matching loop is factored into a shared helper so glob_match() keeps its behaviour.

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/0a6070839b1ef276d5b05bedfb787743e140fb17
• https://git.kernel.org/stable/c/265f3a690f6c7d69ef7d2ca50b04b4853a211df3
• https://git.kernel.org/stable/c/2dad64a97e1df47f5d9ccb17fa319aa348617226
• https://git.kernel.org/stable/c/35ae19764eabfe9c29029d3b5713c86e6855acdf
• https://git.kernel.org/stable/c/56d4c9ab84714eebb285a2fee68aaedf81e3ef15
• https://git.kernel.org/stable/c/e5d5f3bd053a5f14787526c9f0f55ef900d43ac6
• https://git.kernel.org/stable/c/ebb55902856973906c8bb339a3a34824ed4a5086
• https://git.kernel.org/stable/c/ee5b8888d3248618251fb69a2fad92afcb81557e