irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT
In the Linux kernel, the following vulnerability has been resolved: irq_work: Fix use-after-free in irq_work_single() on PREEMPT_RT On PREEMPT_RT, non-HARD irq_work runs in per-CPU kthreads via run_irq_workd(), so irq_work_sync() uses rcuwait() to wait for BUSY==0. After irq_work_single() clears BUSY via atomic_cmpxchg(), it still dereferences @work for irq_work_is_hard() and rcuwait_wake_up(). An irq_work_sync() caller on another CPU that enters after BUSY is cleared can observe BUSY==0 immediately, return, and free the work before those accesses complete — causing a use-after-free. Fix this by wrapping run_irq_workd() in guard(rcu)() so that the entire irq_work_single() execution is within an RCU read-side critical section. Then add synchronize_rcu() in irq_work_sync() after rcuwait_wait_event() to ensure the caller waits for the RCU grace period before returning, preventing premature frees.
CVE-2026-64073
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-2026-64073
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": "810979682ccc98dbd83f341c18a2e556c30a7164",
"lessThan": "2dc79362302922cb18f35e262712b5e58de65442",
"versionType": "git"
},
{
"status": "affected",
"version": "810979682ccc98dbd83f341c18a2e556c30a7164",
"lessThan": "eef4f71b46a9929ac33e968538c9dd5d96a02460",
"versionType": "git"
},
{
"status": "affected",
"version": "810979682ccc98dbd83f341c18a2e556c30a7164",
"lessThan": "684a78183c54c23e70d1cba320f7fc184604210b",
"versionType": "git"
},
{
"status": "affected",
"version": "810979682ccc98dbd83f341c18a2e556c30a7164",
"lessThan": "18c0456ea2615b1a743a6db739c74411c3b42bc6",
"versionType": "git"
},
{
"status": "affected",
"version": "810979682ccc98dbd83f341c18a2e556c30a7164",
"lessThan": "81b582784518196eff1050212a046bc29d3a05dd",
"versionType": "git"
},
{
"status": "affected",
"version": "810979682ccc98dbd83f341c18a2e556c30a7164",
"lessThan": "91840be8f710370607f949a627e070896faeddb8",
"versionType": "git"
}
],
"programFiles": [
"kernel/irq_work.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.142",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.92",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.34",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.11",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"kernel/irq_work.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-64073
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40949 · Revision 1
- Added to Heist Feed
- Publisher date