net/handshake: Take a long-lived file reference at submit
In the Linux kernel, the following vulnerability has been resolved: net/handshake: Take a long-lived file reference at submit handshake_nl_accept_doit() needs the file pointer backing req->hr_sk->sk_socket to survive the window between handshake_req_next() and the subsequent FD_PREPARE() and get_file(). The submit-side sock_hold() does not provide that. sk_refcnt keeps struct sock alive, but struct socket is owned by sock->file: when the consumer fputs the last file reference, sock_release() tears the socket down regardless of any sock_hold. Add an hr_file pointer to struct handshake_req and acquire an explicit reference on sock->file during handshake_req_submit(). handshake_complete() and handshake_req_cancel() release the reference on the completion-bit-winning path. The submit error path must also release the file reference, but after rhashtable insertion a concurrent handshake_req_cancel() can discover the request and race the error path. Gate the error-path cleanup -- sk_destruct restoration, fput, and request destruction -- with test_and_set_bit(HANDSHAKE_F_REQ_COMPLETED), the same serialization handshake_complete() and handshake_req_cancel() already use. When cancel has already claimed ownership, the submit error path returns without touching the request; socket teardown handles final destruction. The accept-side dereferences are not yet retargeted; that change comes in the next patch.
CVE-2026-64523
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-64523
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "3b3009ea8abb713b022d94fba95ec270cf6e7eae",
"lessThan": "22e371a93563c30ebebc576db049785e0d7fc617",
"versionType": "git"
},
{
"status": "affected",
"version": "3b3009ea8abb713b022d94fba95ec270cf6e7eae",
"lessThan": "685b10dd0e32c7782cead16c8cf055c609678583",
"versionType": "git"
},
{
"status": "affected",
"version": "3b3009ea8abb713b022d94fba95ec270cf6e7eae",
"lessThan": "b913801ad9b9a51437d84d030ec6843e08976bd6",
"versionType": "git"
},
{
"status": "affected",
"version": "3b3009ea8abb713b022d94fba95ec270cf6e7eae",
"lessThan": "16eaba5aa89c04eea125905bb8f988c1897f4f29",
"versionType": "git"
},
{
"status": "affected",
"version": "3b3009ea8abb713b022d94fba95ec270cf6e7eae",
"lessThan": "09dba37eee70d0596e26645015f1aa95a9848e9d",
"versionType": "git"
}
],
"programFiles": [
"net/handshake/handshake.h",
"net/handshake/netlink.c",
"net/handshake/request.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.4"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.4",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.93",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.12",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/handshake/handshake.h",
"net/handshake/netlink.c",
"net/handshake/request.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-64523
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #46441 · Revision 1
- Added to Heist Feed
- Publisher date