CVE-2026-52968

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

KVM: s390: pci: fix GAIT table indexing due to double-scaling pointer arithmetic

kvm_s390_pci_aif_enable(), kvm_s390_pci_aif_disable(), and aen_host_forward() index the GAIT by manually multiplying the index with sizeof(struct zpci_gaite).

Since aift->gait is already a struct zpci_gaite pointer, this double-scales the offset, accessing element aisb*16 instead of aisb.

This causes out-of-bounds accesses when aisb >= 32 (with ZPCI_NR_DEVICES=512)

Fix by removing the erroneous sizeof multiplication.

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/11b8ff5b930b351dd1f6f088dce0beb027ac92d0
• https://git.kernel.org/stable/c/16d990a15491cf76cd6eef0846e1b4100e63261a
• https://git.kernel.org/stable/c/31a9d9f9942885aae356a1a57c79e82c5b5b0828
• https://git.kernel.org/stable/c/a99a25db131ece5e6c0f7632da606de631efe4f2
• https://git.kernel.org/stable/c/b22a2da8792a7bfe743c1a922e77fa499ddedbe8
• https://git.kernel.org/stable/c/e7216651b94e92e5433fb2f54b77864642b4ea48