virt: acrn: Fix irqfd use-after-free during eventfd shutdown
In the Linux kernel, the following vulnerability has been resolved: virt: acrn: Fix irqfd use-after-free during eventfd shutdown acrn_irqfd_deassign() and the eventfd EPOLLHUP wakeup can race and free the same struct hsm_irqfd: CPU0 CPU1 ---- ---- eventfd_release() wake_up_poll(EPOLLHUP) hsm_irqfd_wakeup() queue_work(&irqfd->shutdown) acrn_irqfd_deassign() hsm_irqfd_shutdown() list_del_init() eventfd_ctx_remove_wait_queue() eventfd_ctx_put() kfree(irqfd) hsm_irqfd_shutdown_work() container_of(work, ..., shutdown) irqfd->vm <-- use-after-free The deassign path freed the irqfd while a shutdown work item was already queued by EPOLLHUP (or vice versa), so the work item could resurrect a dangling pointer through container_of(). Switch to the lifetime model used by KVM irqfds: - Deassign/deinit only deactivate the irqfd: remove it from vm->irqfds under irqfds_lock and queue the cleanup work. - hsm_irqfd_shutdown_work() becomes the sole owner that unhooks the eventfd waitqueue entry, drops the eventfd reference and frees the irqfd. - A new HSM_IRQFD_FLAG_SHUTDOWN bit guarded by test_and_set_bit() ensures the cleanup work is queued at most once, no matter how many of {EPOLLHUP, deassign, deinit} fire concurrently. This is safe to call from the waitqueue callback, which runs with wqh->lock held and IRQs disabled and therefore cannot take irqfds_lock. - acrn_irqfd_deassign() flushes vm->irqfd_wq before returning so the eventfd is fully detached on return. acrn_irqfd_deinit() deactivate
CVE-2026-97478
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-2026-97478
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": "aa3b483ff1d71c50b33db154048dff9a8f08ac71",
"lessThan": "6e9e007ee1dfb54bc2d070550308077ec28dbaec",
"versionType": "git"
},
{
"status": "affected",
"version": "aa3b483ff1d71c50b33db154048dff9a8f08ac71",
"lessThan": "0e1152f689847b9db2f05454775d34610c1424c2",
"versionType": "git"
},
{
"status": "affected",
"version": "aa3b483ff1d71c50b33db154048dff9a8f08ac71",
"lessThan": "d8156aacfcabb81f52c20ef89094945434d08079",
"versionType": "git"
},
{
"status": "affected",
"version": "aa3b483ff1d71c50b33db154048dff9a8f08ac71",
"lessThan": "666c7f9e07925aa0863348f960e09bb89f8f05a3",
"versionType": "git"
}
],
"programFiles": [
"drivers/virt/acrn/irqfd.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.12"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.12",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.114",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.53",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/virt/acrn/irqfd.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-97478
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #48760 · Revision 1
- Added to Heist Feed
- Publisher date