GHSA-36Q3-P7RR-W76H
Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:32In 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 = NPAGE_SIZE + r (1 <= r < PAGE_SIZE), sendmsg() at iov_base = NPAGE_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->size); the SG-length check covers both directions.
{
"affected": [],
"aliases": [
"CVE-2026-64124"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T16:17:54Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: devmem: reject dma-buf bind with non-page-aligned size or SG length\n\nnet_devmem_bind_dmabuf() trusts dmabuf-\u003esize and sg_dma_len() to be\nPAGE_SIZE multiples without checking:\n\n - tx_vec is sized dmabuf-\u003esize / PAGE_SIZE, and\n net_devmem_get_niov_at() only bounds-checks virt_addr \u003c dmabuf-\u003esize\n before indexing tx_vec[virt_addr / PAGE_SIZE]. With size =\n N*PAGE_SIZE + r (1 \u003c= r \u003c PAGE_SIZE), sendmsg() at iov_base =\n N*PAGE_SIZE passes the bound check and reads tx_vec[N] -- one past.\n\n - owner-\u003earea.num_niovs = len / PAGE_SIZE while gen_pool_add_owner()\n covers the full byte len, so a non-page-multiple non-final sg\n desyncs num_niovs from the gen_pool region for every later sg, on\n both RX and TX.\n\ndma-buf does not require page-aligned sizes, so the bind path has to\nenforce what its own indexing assumes. Reject both with -EINVAL.\n\nThe size check is TX-only (only tx_vec is sized off dmabuf-\u003esize); the\nSG-length check covers both directions.",
"id": "GHSA-36q3-p7rr-w76h",
"modified": "2026-07-20T15:32:00Z",
"published": "2026-07-19T18:31:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64124"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/134c517dfa63203287b2aad6558017f42435a02e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4eb82ba543421e9e38cc14e4e82058b78850df50"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d5008e4e4ee6b739256b796702a7d1aae1b5c3b4"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.