GHSA-J6VR-R53F-G3JF
Vulnerability from github – Published: 2026-08-22 15:31 – Updated: 2026-08-25 06:31In the Linux kernel, the following vulnerability has been resolved:
RDMA/bnxt_re: zero shared page before exposing to userspace
bnxt_re_alloc_ucontext() allocates uctx->shpg via __get_free_page(GFP_KERNEL). The buddy allocator does not zero pages without __GFP_ZERO, so the page contains stale kernel data from whatever object most recently freed it.
The page is then mapped into userspace via vm_insert_page() under BNXT_RE_MMAP_SH_PAGE in bnxt_re_mmap(). The driver only ever writes 4 bytes (a u32 AVID) at offset BNXT_RE_AVID_OFFT (0x10) inside bnxt_re_create_ah(); the remaining 4092 bytes of the page are exposed to userspace unsanitised, leaking kernel memory contents.
Any user with access to /dev/infiniband/uverbsX on a host with a bnxt_re device (typically rdma group membership) can read this data via a single mmap() at pgoff 0 after IB_USER_VERBS_CMD_GET_CONTEXT.
Other shared pages in the same file already use get_zeroed_page() correctly:
drivers/infiniband/hw/bnxt_re/ib_verbs.c srq->uctx_srq_page = (void )get_zeroed_page(GFP_KERNEL); cq->uctx_cq_page = (void )get_zeroed_page(GFP_KERNEL);
uctx->shpg is the only outlier. Bring it in line with the existing convention by switching to get_zeroed_page().
{
"affected": [],
"aliases": [
"CVE-2026-74584"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-22T15:16:21Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/bnxt_re: zero shared page before exposing to userspace\n\nbnxt_re_alloc_ucontext() allocates uctx-\u003eshpg via\n__get_free_page(GFP_KERNEL). The buddy allocator does not zero pages\nwithout __GFP_ZERO, so the page contains stale kernel data from\nwhatever object most recently freed it.\n\nThe page is then mapped into userspace via vm_insert_page() under\nBNXT_RE_MMAP_SH_PAGE in bnxt_re_mmap(). The driver only ever writes\n4 bytes (a u32 AVID) at offset BNXT_RE_AVID_OFFT (0x10) inside\nbnxt_re_create_ah(); the remaining 4092 bytes of the page are exposed\nto userspace unsanitised, leaking kernel memory contents.\n\nAny user with access to /dev/infiniband/uverbsX on a host with a\nbnxt_re device (typically rdma group membership) can read this data\nvia a single mmap() at pgoff 0 after IB_USER_VERBS_CMD_GET_CONTEXT.\n\nOther shared pages in the same file already use get_zeroed_page()\ncorrectly:\n\n drivers/infiniband/hw/bnxt_re/ib_verbs.c\n srq-\u003euctx_srq_page = (void *)get_zeroed_page(GFP_KERNEL);\n cq-\u003euctx_cq_page = (void *)get_zeroed_page(GFP_KERNEL);\n\nuctx-\u003eshpg is the only outlier. Bring it in line with the existing\nconvention by switching to get_zeroed_page().",
"id": "GHSA-j6vr-r53f-g3jf",
"modified": "2026-08-25T06:31:21Z",
"published": "2026-08-22T15:31:04Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74584"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/53c97e9882f4e747b4ac31b211317c2eba541af9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9128c2411b83a64c0a69d2ff059c741bde25a9cc"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9896bdfd21d918e9f26a52bc6109cc77970ee0b1"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a3ed2daab02b2a706e882ad31b5c3c4f33cb5bb1"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c19b360fa10c521c0b681875cdaa51545d45a491"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c75f8ce4baa29ae57fe615c6a2c5101f59b8b89a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e2b143df29003d2704b51f62e9297006953dbacb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f6b079629becfa977f9c51fe53ad2e6dcc55ef44"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N",
"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.