CVE-2026-74671: ima: fix out-of-bounds read in xattr_verify()
ima: fix out-of-bounds read in xattrverify()
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.6.152.1-1
Event History
Frequently Asked Questions
What input is required to trigger the out-of-bounds read?
The vulnerable path requires a truncated security.ima extended attribute, specifically an IMA_XATTR_DIGEST_NG value whose length is too short for the subsequent digest comparison. The described example is a one-byte xattr, where the length calculation underflows and allows memcmp() to read beyond the allocated xattr buffer.
Does the absence of an EVM HMAC key prevent exposure?
No. When no HMAC key is loaded, evm_verifyxattr() returns INTEGRITY_UNKNOWN rather than rejecting the xattr, allowing a truncated security.ima value to reach xattr_verify() unchanged.
How can this issue be mitigated if the fix cannot be applied immediately?
The provided data identifies malformed or truncated security.ima xattrs as the triggering condition. Avoiding or rejecting such xattr values prevents the described out-of-bounds read path, although no specific configuration-only mitigation is provided.