GHSA-43G4-4J68-8XJ3
Vulnerability from github – Published: 2025-08-19 18:31 – Updated: 2025-11-26 18:30In the Linux kernel, the following vulnerability has been resolved:
xen: fix UAF in dmabuf_exp_from_pages()
[dma_buf_fd() fixes; no preferences regarding the tree it goes through - up to xen folks]
As soon as we'd inserted a file reference into descriptor table, another thread could close it. That's fine for the case when all we are doing is returning that descriptor to userland (it's a race, but it's a userland race and there's nothing the kernel can do about it). However, if we follow fd_install() with any kind of access to objects that would be destroyed on close (be it the struct file itself or anything destroyed by its ->release()), we have a UAF.
dma_buf_fd() is a combination of reserving a descriptor and fd_install(). gntdev dmabuf_exp_from_pages() calls it and then proceeds to access the objects destroyed on close - starting with gntdev_dmabuf itself.
Fix that by doing reserving descriptor before anything else and do fd_install() only when everything had been set up.
{
"affected": [],
"aliases": [
"CVE-2025-38595"
],
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-08-19T17:15:37Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nxen: fix UAF in dmabuf_exp_from_pages()\n\n[dma_buf_fd() fixes; no preferences regarding the tree it goes through -\nup to xen folks]\n\nAs soon as we\u0027d inserted a file reference into descriptor table, another\nthread could close it. That\u0027s fine for the case when all we are doing is\nreturning that descriptor to userland (it\u0027s a race, but it\u0027s a userland\nrace and there\u0027s nothing the kernel can do about it). However, if we\nfollow fd_install() with any kind of access to objects that would be\ndestroyed on close (be it the struct file itself or anything destroyed\nby its -\u003erelease()), we have a UAF.\n\ndma_buf_fd() is a combination of reserving a descriptor and fd_install().\ngntdev dmabuf_exp_from_pages() calls it and then proceeds to access the\nobjects destroyed on close - starting with gntdev_dmabuf itself.\n\nFix that by doing reserving descriptor before anything else and do\nfd_install() only when everything had been set up.",
"id": "GHSA-43g4-4j68-8xj3",
"modified": "2025-11-26T18:30:58Z",
"published": "2025-08-19T18:31:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38595"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3edfd2353f301bfffd5ee41066e37320a59ccc2d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/532c8b51b3a8676cbf533a291f8156774f30ea87"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d59d49af4aeed9a81e673e37c26c6a3bacf1a181"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e5907885260401bba300d4d18d79875c05b82651"
}
],
"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 |
|---|
Nomenclature
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- 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.