Out-of-bounds write in Linux kernel - CVE-2026-80810

Vulnerability details

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.

Affected software

How to mitigate CVE-2026-80810

External 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

Related Security Bulletins

• Out-of-bounds write in Linux kernel io_uring