CVE-2022-50231

A flaw was found in the Linux kernel's arm64/poly1305 cryptographic module. A local user could exploit this vulnerability by providing specially crafted input during the initialization of the neon_poly1305_blocks function. This out-of-bounds read could lead to a denial of service (DoS) or potentially result in information disclosure.

A moderate out-of-bounds read flaw was found in the arm64 NEON implementation of the Poly1305 hash algorithm in the Linux kernel (arch/arm64/crypto/poly1305-glue.c), affecting 64-bit ARM (aarch64) systems. When neon_poly1305_blocks() is called with both the r[] and s[] state uninitialized, it treats the first input block as 32 bytes, reading 16 bytes for the key and a further 16 bytes for s[] even though only 16 bytes are actually consumed for initialization, so the function can read past the end of the input buffer. A local user able to pass specially crafted, shorter-than-expected input to the Poly1305 hash, for example through the AF_ALG setsockopt interface as reached via the ESSIV skcipher setkey path, could trigger this out-of-bounds read to cause a denial of service or potentially disclose small amounts of kernel memory. Red Hat rated this flaw Moderate severity (CVSS 6.1, AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H), while NIST and CVE.org scored it 7.1 (Important) with a higher confidentiality impact; the difference reflects Red Hat assessing the confidentiality impact as low rather than high. Per the current assessment, the kernel and kernel-rt packages in Red Hat Enterprise Linux 9 and Red Hat In-Vehicle OS 1 are listed as affected, while Red Hat Enterprise Linux 6, 7, 8, and 10, and the Hosted OpenShift offerings are not affected because the vulnerable code is not present in those kernels.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.