SB20260727277 - Out-of-bounds write in Linux kernel iommu iommufd driver

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds write (CVE-ID: CVE-2026-64293)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows a local user to overwrite memory in a user-supplied buffer.

The vulnerability exists due to an out-of-bounds write in iommufd_veventq_fops_read() when reading normal vEVENT records. A local user can trigger the function with a crafted buffer size and event data length to overwrite memory in a user-supplied buffer.

This affects 32-bit systems because the bounds check uses the size of a pointer instead of the full header size.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/04a177f91160ee18da98f5689482cf0f589ec869
• https://git.kernel.org/stable/c/0cdbb97a4dbd69abdd2ab998b4fbc7803d4b0b72
• https://git.kernel.org/stable/c/be93d186ae88a92e7aa77e122d4e661fa57b1e39