In the Linux kernel, the following vulnerability has been resolved: blk-mq: pop cached request if it is usable When submitting a bio to blk-mq, if the task should sleep after peeking a cached request, but before it pops it, the plug flushes and calls blk_mq_free_plug_rqs, freeing the cached_rqs. This creates a use-after-free bug. Fix this by popping the cached request before any possible blocking calls if it is suitable for use. Popping this request first holds a queue reference, so avoid any serialization races with queue freezes and can safely proceed with dispatching that request to the driver. This potentially increases a timing window from when a driver wants to freeze its queue to when requests stop being dispatched. That scenario is off the fast path though, and drivers need to appropriately handle requests during a freeze request anyway. The downside is the popped element needs to be individually freed when we performed a bio plug merge. The cached request would have had to be freed later anyway, but this patch does it inline with building the plug list instead of after flushing it.

The remote AlmaLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the ALSA-2026:47040 advisory.

    * kernel: xfrm: Duplicate SPI Handling (CVE-2025-39797)
      * kernel: lib/buildid: use __kernel_read() for sleepable context (CVE-2026-23002)
      * kernel: futex: Drop CLONE_THREAD requirement for private default hash alloc (CVE-2026-52973)
      * kernel: iommu/vt-d: Avoid NULL pointer dereference or refcount corruption (CVE-2026-53281)
      * kernel: blk-mq: pop cached request if it is usable (CVE-2026-64017)


    Bug Fix(es) and Enhancement(s):

      * general protection fault during exportfs / nfsd4_revoke_states [almalinux-9.8.z]     (JIRA:AlmaLinux-188257)
      * Enable Pretimeout Watchdog Panic Functionality on x86 [almalinux-9.8.z] (JIRA:AlmaLinux-193729)

Tenable has extracted the preceding description block directly from the AlmaLinux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Oracle Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the ELSA-2026-47040 advisory.

    - blk-mq: reinsert cached request to the list (CKI Backport Bot) [RHEL-213163] {CVE-2026-64017}
    - blk-mq: pop cached request if it is usable (CKI Backport Bot) [RHEL-213163] {CVE-2026-64017}
    - futex: Drop CLONE_THREAD requirement for private default hash alloc (Audra Mitchell) [RHEL-193517]     {CVE-2026-52973}
    - xfrm: xfrm_alloc_spi shouldn't use 0 as SPI (Sabrina Dubroca) [RHEL-180033] {CVE-2025-39797}
    - xfrm: Duplicate SPI Handling (Sabrina Dubroca) [RHEL-180033] {CVE-2025-39797}
    - iommu/vt-d: Avoid NULL pointer dereference or refcount corruption (Eder Zulian) [RHEL-190342]     {CVE-2026-53281}
    - lib/buildid: use __kernel_read() for sleepable context (CKI Backport Bot) [RHEL-189962] {CVE-2026-23002}

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote RockyLinux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RLSA-2026:47040 advisory.

    * kernel: xfrm: Duplicate SPI Handling (CVE-2025-39797)

    * kernel: lib/buildid: use __kernel_read() for sleepable context (CVE-2026-23002)

    * kernel: futex: Drop CLONE_THREAD requirement for private default hash alloc (CVE-2026-52973)

    * kernel: iommu/vt-d: Avoid NULL pointer dereference or refcount corruption (CVE-2026-53281)

    * kernel: blk-mq: pop cached request if it is usable (CVE-2026-64017)

    Bug Fix(es) and Enhancement(s):

    * general protection fault during exportfs / nfsd4_revoke_states [rhel-9.8.z] (JIRA:Rocky Linux-188257)

    * Enable Pretimeout Watchdog Panic Functionality on x86 [rhel-9.8.z] (JIRA:Rocky Linux-193729)

Tenable has extracted the preceding description block directly from the RockyLinux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:47040 advisory.

    The kernel packages contain the Linux kernel, the core of any Linux operating system.

    Security Fix(es):

    * kernel: xfrm: Duplicate SPI Handling (CVE-2025-39797)

    * kernel: lib/buildid: use __kernel_read() for sleepable context (CVE-2026-23002)

    * kernel: futex: Drop CLONE_THREAD requirement for private default hash alloc (CVE-2026-52973)

    * kernel: iommu/vt-d: Avoid NULL pointer dereference or refcount corruption (CVE-2026-53281)

    * kernel: blk-mq: pop cached request if it is usable (CVE-2026-64017)

    Bug Fix(es) and Enhancement(s):

    * general protection fault during exportfs / nfsd4_revoke_states [rhel-9.8.z] (JIRA:RHEL-188257)

    * Enable Pretimeout Watchdog Panic Functionality on x86 [rhel-9.8.z] (JIRA:RHEL-193729)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - blk-mq: pop cached request if it is usable When submitting a bio to blk-mq, if the task should sleep after     peeking a cached request, but before it pops it, the plug flushes and calls blk_mq_free_plug_rqs, freeing     the cached_rqs. This creates a use-after-free bug. Fix this by popping the cached request before any     possible blocking calls if it is suitable for use. Popping this request first holds a queue reference, so     avoid any serialization races with queue freezes and can safely proceed with dispatching that request to     the driver. This potentially increases a timing window from when a driver wants to freeze its queue to     when requests stop being dispatched. That scenario is off the fast path though, and drivers need to     appropriately handle requests during a freeze request anyway. The downside is the popped element needs to     be individually freed when we performed a bio plug merge. The cached request would have had to be freed     later anyway, but this patch does it inline with building the plug list instead of after flushing it.
    (CVE-2026-64017)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
331609	AlmaLinux 9 : kernel (ALSA-2026:47040)	Nessus	Alma Linux Local Security Checks	Local	high
331544	Oracle Linux 9 : kernel (ELSA-2026-47040)	Nessus	Oracle Linux Local Security Checks	Local	high
331314	RockyLinux 9 : kernel (RLSA-2026:47040)	Nessus	Rocky Linux Local Security Checks	Local	high
330427	RHEL 9 : kernel (RHSA-2026:47040)	Nessus	Red Hat Local Security Checks	Local	high
327910	Linux Distros Unpatched Vulnerability : CVE-2026-64017	Nessus	Misc.	Local	high

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CVE-2026-64017

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Tenable Plugins

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