io_uring/eventfd: ensure io_eventfd_signal() defers another RCU period
In the Linux kernel, the following vulnerability has been resolved: io_uring/eventfd: ensure io_eventfd_signal() defers another RCU period io_eventfd_do_signal() is invoked from an RCU callback, but when dropping the reference to the io_ev_fd, it calls io_eventfd_free() directly if the refcount drops to zero. This isn't correct, as any potential freeing of the io_ev_fd should be deferred another RCU grace period. Just call io_eventfd_put() rather than open-code the dec-and-test and free, which will correctly defer it another RCU grace period.
CVE-2025-21655
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-2025-21655
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": "21a091b970cdbcf3e8ff829234b51be6f9192766",
"lessThan": "6b63308c28987c6010b1180c72a6db4df6c68033",
"versionType": "git"
},
{
"status": "affected",
"version": "21a091b970cdbcf3e8ff829234b51be6f9192766",
"lessThan": "8efff2aa2d95dc437ab67c5b4a9f1d3f367baa10",
"versionType": "git"
},
{
"status": "affected",
"version": "21a091b970cdbcf3e8ff829234b51be6f9192766",
"lessThan": "a7085c3ae43b86d4b3d1b8275e6a67f14257e3b7",
"versionType": "git"
},
{
"status": "affected",
"version": "21a091b970cdbcf3e8ff829234b51be6f9192766",
"lessThan": "c9a40292a44e78f71258b8522655bffaf5753bdb",
"versionType": "git"
}
],
"programFiles": [
"io_uring/eventfd.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.1"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.125",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.72",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.10",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.13",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"io_uring/eventfd.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-21655
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #26899 · Revision 1
- Added to Heist Feed
- Publisher date