CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HIn the Linux kernel, the following vulnerability has been resolved: ima: fix out-of-bounds read in xattr_verify() The digest-length check in xattr_verify() mixes int and size_t: if (xattr_len - sizeof(xattr_value->type) - hash_start >= iint->ima_hash->length) sizeof() yields size_t, so the usual arithmetic conversions promote the whole left-hand side to unsigned 64-bit before the subtraction runs. For a truncated xattr this underflows instead of going negative: a 1-byte IMA_XATTR_DIGEST_NG xattr (xattr_len == 1, hash_start == 1) turns "1 - 1 - 1" into SIZE_MAX, which is trivially >= ima_hash->length. The check then passes and the following memcmp() reads iint->ima_hash->length bytes starting past the end of the buffer vfs_getxattr_alloc() allocated for it. Nothing upstream clamps xattr_len back into a safe range first: ima_get_hash_algo() only special-cases xattr_len < 2 to pick a default algorithm, and evm_verifyxattr() returns INTEGRITY_UNKNOWN rather than failing when no HMAC key is loaded, so a truncated security.ima value reaches the length check as-is. Rewrite the comparison so every operand stays a signed int and no implicit conversion to size_t can occur. A flaw was found in the Linux kernel's Integrity Measurement Architecture (IMA) subsystem. The `xattr_verify()` function, which verifies extended attributes, incorrectly mixes `int` and `size_t` data types in its digest-length check. This can lead to an integer underflow when processing a truncated extended attribute, bypassing a bounds check. As a result, a memory comparison operation reads beyond the allocated buffer, causing an out-of-bounds read that could lead to information disclosure or system instability.
Multiple vulnerabilities have been discovered in the Linux kernel of Debian. These vulnerabilities allow for privilege escalation, data compromise, and denial of service. The affected Debian versions are prior to 6.12.10…