CVE-2026-64124

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

net: devmem: reject dma-buf bind with non-page-aligned size or SG length

net_devmem_bind_dmabuf() trusts dmabuf->size and sg_dma_len() to be

PAGE_SIZE multiples without checking:

- tx_vec is sized dmabuf->size / PAGE_SIZE, and

net_devmem_get_niov_at() only bounds-checks virt_addr < dmabuf->size

before indexing tx_vec[virt_addr / PAGE_SIZE]. With size =

N*PAGE_SIZE + r (1 <= r < PAGE_SIZE), sendmsg() at iov_base =

N*PAGE_SIZE passes the bound check and reads tx_vec[N] -- one past.

- owner->area.num_niovs = len / PAGE_SIZE while gen_pool_add_owner()

covers the full byte len, so a non-page-multiple non-final sg

desyncs num_niovs from the gen_pool region for every later sg, on

both RX and TX.

dma-buf does not require page-aligned sizes, so the bind path has to

enforce what its own indexing assumes. Reject both with -EINVAL.

The size check is TX-only (only tx_vec is sized off dmabuf->si

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References