SB20261022334 - Out-of-bounds read in Linux kernel char tpm driver

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds read (CVE-ID: CVE-2026-98728)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local user to disclose stale buffer contents through random bytes returned to a caller.

The vulnerability exists due to an out-of-bounds read in the Linux kernel's tpm2_get_random() function when processing a truncated TPM response carrying the TPM2_ST_SESSIONS tag. A local user can supply such a response to bypass a length check that fails to account for the skipped 4-byte parameter size field, causing memcpy() to read up to 4 bytes past the response end and copy stale buffer contents into the caller's random bytes.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/42bb6216b861e892512128219ff23010d656ba14
• https://git.kernel.org/stable/c/9b522400bf5c082feb9a0037a053ea822a2c7e4d
• https://git.kernel.org/stable/c/be54101992c2c5218be0e0a87827ccc96e3089af
• https://git.kernel.org/stable/c/e30a2406408d2df6d9cd48c2e59e913cf266a05a