GHSA-75CJ-Q634-PHHQ
Vulnerability from github – Published: 2026-08-22 18:30 – Updated: 2026-08-25 06:31In the Linux kernel, the following vulnerability has been resolved:
net: smc: fix splice entry lifetime imbalance in smc_rx_splice
smc_rx_splice() passes pages to splice_to_pipe() before taking the references that cover the lifetime of each splice entry. In the VM-backed RMB path, splice_to_pipe() may drop unqueued entries through smc_rx_spd_release(), while queued entries are released later via the pipe buffer callback.
The old post-splice accounting also derives the number of queued VM pages from an offset mutated while building the descriptor, and a multi-page splice pairs one sock_hold() with multiple sock_put() calls.
Take the page and socket references for every candidate entry before splice_to_pipe(), and drop the matching private state, page reference, and socket reference from smc_rx_spd_release() for entries that never get queued. This fixes a refcount imbalance that can underflow page refcounts and trigger a use-after-free.
{
"affected": [],
"aliases": [
"CVE-2026-74631"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-22T16:16:36Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: smc: fix splice entry lifetime imbalance in smc_rx_splice\n\nsmc_rx_splice() passes pages to splice_to_pipe() before taking the\nreferences that cover the lifetime of each splice entry. In the\nVM-backed RMB path, splice_to_pipe() may drop unqueued entries through\nsmc_rx_spd_release(), while queued entries are released later via the\npipe buffer callback.\n\nThe old post-splice accounting also derives the number of queued VM pages\nfrom an offset mutated while building the descriptor, and a multi-page\nsplice pairs one sock_hold() with multiple sock_put() calls.\n\nTake the page and socket references for every candidate entry before\nsplice_to_pipe(), and drop the matching private state, page reference,\nand socket reference from smc_rx_spd_release() for entries that never\nget queued. This fixes a refcount imbalance that can underflow page\nrefcounts and trigger a use-after-free.",
"id": "GHSA-75cj-q634-phhq",
"modified": "2026-08-25T06:31:24Z",
"published": "2026-08-22T18:30:27Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74631"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/07ad246529d136d5ef441d5ab4c305d132ff3090"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0b7d54cedea5cb158e21925ae0c6c2f5c87ed2a0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4515c78f4d9fd577270f012efeb062ea58b3682d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5d9686af2976741bbd79b150d1c9e60b81e7f12e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7ddc7af2ae7fc5a0c0635b245c0824c8b76de5cb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/af02c67ce654356c58db20a0bb2db33ace3b07a8"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c841789e456ec6751342fa800639ce8e82ff0e6b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ca8342b5fc24c249fdb998468f6a168b457c67e5"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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