futex: Prevent rcuwait use-after-free during requeue PI
In the Linux kernel, the following vulnerability has been resolved: futex: Prevent rcuwait use-after-free during requeue PI On PREEMPT_RT, FUTEX_CMP_REQUEUE_PI can trigger a KASAN report (slab-out-of-bounds) in futex_requeue_pi_complete() invocation of rcuwait_wake_up(). The futex_q used by futex_wait_requeue_pi() is allocated on the waiter's stack. An early wakeup can race with a PI requeue as follows: waiter requeue task ------ ------------ futex_wait_requeue_pi() futex_do_wait() schedule() futex_requeue futex_proxy_trylock_atomic() futex_requeue_pi_prepare() Q_REQUEUE_PI_NONE -> Q_REQUEUE_PI_IN_PROGRESS * timeout/ signal wakes waiter * futex_requeue_pi_wakeup_sync() Q_REQUEUE_PI_IN_PROGRESS -> Q_REQUEUE_PI_WAIT requeue_pi_wake_futex futex_requeue_pi_complete() cmpxchg Q_REQUEUE_PI_WAIT -> Q_REQUEUE_PI_LOCKED rcuwait_wait_event() if (atomic_read(&q->requeue_state) != Q_REQUEUE_PI_WAIT) break /* no schedule() */ /* q.pi_state->owner == current */ futex_private_hash_put() /* return from syscall */ rcuwait_wake_up(&q->requeue_wait) /* q is gone */ futex_requeue_pi_complete() publishes Q_REQUEUE_PI_LOCKED before calling rcuwait_wake_up(). The waiter observes this state in rcuwait_wait_event() before invoking schedule() in rcuwait_wait_event(). Here, the waiter is free leave the syscall before requeue task can complete the wake. To address this race skip rcuwait_wake_up() in the Q_REQUEUE_PI_LOCKED case. This state is only published by requeue_pi_wake_futex(), which saves q->tas
CVE-2026-90003
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-2026-90003
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": "07d91ef510fb16a2e0ca7453222105835b7ba3b8",
"lessThan": "220ee9e04ca3b7f014c000264aa6c884f036c86e",
"versionType": "git"
},
{
"status": "affected",
"version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8",
"lessThan": "81aadbd09bf1dcd3238212f336ba699503557ae8",
"versionType": "git"
},
{
"status": "affected",
"version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8",
"lessThan": "244f301759fd34b1dd0b4192ce44f8ef224e027d",
"versionType": "git"
},
{
"status": "affected",
"version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8",
"lessThan": "7d1559126d86be6e4f6a85663dfbfe85caa47e37",
"versionType": "git"
},
{
"status": "affected",
"version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8",
"lessThan": "e4a4ccfa470f910b747b3ee8d18670ed8ac8a236",
"versionType": "git"
},
{
"status": "affected",
"version": "07d91ef510fb16a2e0ca7453222105835b7ba3b8",
"lessThan": "a3b8d46fe401cba3a5c46dea610e6eb3dc15370e",
"versionType": "git"
}
],
"programFiles": [
"kernel/futex/requeue.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.15"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.15",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.51",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.5",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"kernel/futex/requeue.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-90003
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #36436 · Revision 1
- Added to Heist Feed
- Publisher date