SB20260905137 - Out-of-bounds write in Linux kernel io_uring

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds write (CVE-ID: CVE-2026-80810)

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

CVSSv4: 7.3 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause out-of-bounds reads and writes.

The vulnerability exists due to an integer shift overflow in io_vec_fill_bvec() in io_uring/rsrc.c when processing an iovec associated with a registered buffer backed by a folio with a shift of at least 32. A local user can submit crafted iovecs to cause out-of-bounds reads and writes.

On arm64 systems with 64K pages, the required folio can be a 16G hugetlb page; powerpc systems can also support the required folio size.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/3267d7c8ba51642117f7bdd1ece02b2540668476
• https://git.kernel.org/stable/c/3f3a6a16bbe8bde76532d9415438f8cdef439e5d
• https://git.kernel.org/stable/c/45c945107e007b1fb73e21cd220277652a45521a
• https://git.kernel.org/stable/c/6b308c37fbeba3aa8c634fb1ed53e2f63a5d5a5c