GHSA-85RQ-57VX-88Q2
Vulnerability from github – Published: 2026-03-18 12:31 – Updated: 2026-07-14 15:31In the Linux kernel, the following vulnerability has been resolved:
RDMA/umad: Reject negative data_len in ib_umad_write
ib_umad_write computes data_len from user-controlled count and the MAD header sizes. With a mismatched user MAD header size and RMPP header length, data_len can become negative and reach ib_create_send_mad(). This can make the padding calculation exceed the segment size and trigger an out-of-bounds memset in alloc_send_rmpp_list().
Add an explicit check to reject negative data_len before creating the send buffer.
KASAN splat: [ 211.363464] BUG: KASAN: slab-out-of-bounds in ib_create_send_mad+0xa01/0x11b0 [ 211.364077] Write of size 220 at addr ffff88800c3fa1f8 by task spray_thread/102 [ 211.365867] ib_create_send_mad+0xa01/0x11b0 [ 211.365887] ib_umad_write+0x853/0x1c80
{
"affected": [],
"aliases": [
"CVE-2026-23243"
],
"database_specific": {
"cwe_ids": [
"CWE-787"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-03-18T11:16:16Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/umad: Reject negative data_len in ib_umad_write\n\nib_umad_write computes data_len from user-controlled count and the\nMAD header sizes. With a mismatched user MAD header size and RMPP\nheader length, data_len can become negative and reach ib_create_send_mad().\nThis can make the padding calculation exceed the segment size and trigger\nan out-of-bounds memset in alloc_send_rmpp_list().\n\nAdd an explicit check to reject negative data_len before creating the\nsend buffer.\n\nKASAN splat:\n[ 211.363464] BUG: KASAN: slab-out-of-bounds in ib_create_send_mad+0xa01/0x11b0\n[ 211.364077] Write of size 220 at addr ffff88800c3fa1f8 by task spray_thread/102\n[ 211.365867] ib_create_send_mad+0xa01/0x11b0\n[ 211.365887] ib_umad_write+0x853/0x1c80",
"id": "GHSA-85rq-57vx-88q2",
"modified": "2026-07-14T15:31:40Z",
"published": "2026-03-18T12:31:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23243"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-019113.html"
},
{
"type": "WEB",
"url": "https://cert-portal.siemens.com/productcert/html/ssa-082556.html"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1371ef6b1ecf3676b8942f5dfb3634fb0648128e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/205955f29c26330b1dc7fdeadd5bb97c38e26f56"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/362e45fd9069ffa1523f9f1633b606ebf72060d7"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5551b02fdbfd85a325bb857f3a8f9c9f33397ed2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6eb2919474ca105c5b13d19574e25f0ddcf19ca2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9c80d688f402539dfc8f336de1380d6b4ee14316"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0d"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.