Linux Kernel up to 5.14.10 block rq_qos_done_bio denial of service

Summaryinfo

A vulnerability labeled as critical has been found in Linux Kernel up to 5.14.10. The impacted element is the function rq_qos_done_bio of the component block. Executing a manipulation can lead to denial of service. This vulnerability is tracked as CVE-2021-47412. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as critical was found in Linux Kernel up to 5.14.10. This vulnerability affects the function rq_qos_done_bio of the component block. The manipulation with an unknown input leads to a denial of service vulnerability. The CWE definition for the vulnerability is CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. As an impact it is known to affect availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: block: don't call rq_qos_ops->done_bio if the bio isn't tracked rq_qos framework is only applied on request based driver, so: 1) rq_qos_done_bio() needn't to be called for bio based driver 2) rq_qos_done_bio() needn't to be called for bio which isn't tracked, such as bios ended from error handling code. Especially in bio_endio(): 1) request queue is referred via bio->bi_bdev->bd_disk->queue, which may be gone since request queue refcount may not be held in above two cases 2) q->rq_qos may be freed in blk_cleanup_queue() when calling into __rq_qos_done_bio() Fix the potential kernel panic by not calling rq_qos_ops->done_bio if the bio isn't tracked. This way is safe because both ioc_rqos_done_bio() and blkcg_iolatency_done_bio() are nop if the bio isn't tracked.

The advisory is shared for download at git.kernel.org. This vulnerability was named CVE-2021-47412 since 05/21/2024. There are known technical details, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 207773 (Oracle Linux 8 : kernel (ELSA-2024-7000)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.14.11 eliminates this vulnerability. Applying the patch 004b8f8a6912/a647a524a467 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (207773) and CERT Bund (WID-SEC-2024-1197). Once again VulDB remains the best source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• IBM InfoSphere Guardium
• Oracle Linux
• EMC Avamar
• Dell NetWorker
• IBM Security Guardium
• RESF Rocky Linux
• Broadcom Brocade SANnav
• Open Source Linux Kernel
• IBM Business Automation Workflow
• IBM Spectrum Protect Plus
• IBM QRadar SIEM
• Dell Avamar
• Juniper Junos Space
• IBM DB2
• IBM Storage Scale System
• SolarWinds Security Event Manager
• Dell PowerProtect Data Domain
• Dell PowerProtect Data Domain Management Center
• Dell PowerProtect Data Domain OS

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.14.0
• 5.14.1
• 5.14.2
• 5.14.3
• 5.14.4
• 5.14.5
• 5.14.6
• 5.14.7
• 5.14.8
• 5.14.9
• 5.14.10

License

• open-source

Website

• Vendor: https://www.kernel.org/

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Once again VulDB remains the best source for vulnerability data.

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