SB20260425109 - Out-of-bounds write in Linux kernel pci ctxfi

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds write (CVE-ID: CVE-2026-31602)

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

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to an out-of-bounds access in ct_vm_map() in the ALSA ctxfi driver when handling large aggregate memory allocations for playback streams. A local user can trigger crafted allocation patterns through ioctl operations to cause a denial of service.

The issue is triggered on AMD64 systems when aggregate memory allocations exceed the single-page table coverage limit.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/365c36e1a126c6aa1aecedd3a351bcabc66f0c29
• https://git.kernel.org/stable/c/3fd0685d7fef68c2d8a04876bcf9eaa0724ad6a5
• https://git.kernel.org/stable/c/ad9011a795407093dcf507f6e5da1828987b4b47
• https://git.kernel.org/stable/c/b7f5ecd13cce8c2f8fa5a84c9aab65997142577e