CVE-2024-41014

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

xfs: add bounds checking to xlog_recover_process_data

There is a lack of verification of the space occupied by fixed members of xlog_op_header in the xlog_recover_process_data.

We can create a crafted image to trigger an out of bounds read by following these steps: 1) Mount an image of xfs, and do some file operations to leave records 2) Before umounting, copy the image for subsequent steps to simulate abnormal exit. Because umount will ensure that tail_blk and head_blk are the same, which will result in the inability to enter xlog_recover_process_data 3) Write a tool to parse and modify the copied image in step 2 4) Make the end of the xlog_op_header entries only 1 byte away from xlog_rec_header->h_size 5) xlog_rec_header->h_num_logops++ 6) Modify xlog_rec_header->h_crc

Fix: Add a check to make sure there is sufficient space to access fixed members of xlog_op_header.

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/7cd9f0a33e738cd58876f1bc8d6c1aa5bc4fc8c1
• https://git.kernel.org/stable/c/d1e3efe783365db59da88f08a2e0bfe1cc95b143
• https://git.kernel.org/stable/c/fb63435b7c7dc112b1ae1baea5486e0a6e27b196
• https://git.kernel.org/stable/c/fb63435b7c7dc112b1ae1baea5486e0a6e27b196
• https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html