rseq: Fix segfault on registration when rseq_cs is non-zero
In the Linux kernel, the following vulnerability has been resolved: rseq: Fix segfault on registration when rseq_cs is non-zero The rseq_cs field is documented as being set to 0 by user-space prior to registration, however this is not currently enforced by the kernel. This can result in a segfault on return to user-space if the value stored in the rseq_cs field doesn't point to a valid struct rseq_cs. The correct solution to this would be to fail the rseq registration when the rseq_cs field is non-zero. However, some older versions of glibc will reuse the rseq area of previous threads without clearing the rseq_cs field and will also terminate the process if the rseq registration fails in a secondary thread. This wasn't caught in testing because in this case the leftover rseq_cs does point to a valid struct rseq_cs. What we can do is clear the rseq_cs field on registration when it's non-zero which will prevent segfaults on registration and won't break the glibc versions that reuse rseq areas on thread creation.
CVE-2025-38067
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-2025-38067
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": "d7822b1e24f2df5df98c76f0e94a5416349ff759",
"lessThan": "48900d839a3454050fd5822e34be8d54c4ec9b86",
"versionType": "git"
},
{
"status": "affected",
"version": "d7822b1e24f2df5df98c76f0e94a5416349ff759",
"lessThan": "3e4028ef31b69286c9d4878cee0330235f53f218",
"versionType": "git"
},
{
"status": "affected",
"version": "d7822b1e24f2df5df98c76f0e94a5416349ff759",
"lessThan": "b2b05d0dc2f4f0646922068af435aed5763d16ba",
"versionType": "git"
},
{
"status": "affected",
"version": "d7822b1e24f2df5df98c76f0e94a5416349ff759",
"lessThan": "eaf112069a904b6207b4106ff083e0208232a2eb",
"versionType": "git"
},
{
"status": "affected",
"version": "d7822b1e24f2df5df98c76f0e94a5416349ff759",
"lessThan": "f004f58d18a2d3dc761cf973ad27b4a5997bd876",
"versionType": "git"
},
{
"status": "affected",
"version": "d7822b1e24f2df5df98c76f0e94a5416349ff759",
"lessThan": "2df285dab00fa03a3ef939b6cb0d0d0aeb0791db",
"versionType": "git"
},
{
"status": "affected",
"version": "d7822b1e24f2df5df98c76f0e94a5416349ff759",
"lessThan": "fd881d0a085fc54354414aed990ccf05f282ba53",
"versionType": "git"
}
],
"programFiles": [
"kernel/rseq.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.18",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.240",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.189",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.146",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.99",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.39",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.14.9",
"versionType": "semver",
"lessThanOrEqual": "6.14.*"
},
{
"status": "unaffected",
"version": "6.15",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"kernel/rseq.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-38067
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #27012 · Revision 1
- Added to Heist Feed
- Publisher date