Linux Kernel up to 5.15.32/5.16.18/5.17.1 blk_alloc_ext_minor privilege escalation

Summaryinfo

A vulnerability marked as problematic has been reported in Linux Kernel up to 5.15.32/5.16.18/5.17.1. The impacted element is the function blk_alloc_ext_minor. This manipulation causes an unknown weakness. The identification of this vulnerability is CVE-2022-49147. There is no exploit available. It is suggested to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 5.15.32/5.16.18/5.17.1. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: block: Fix the maximum minor value is blk_alloc_ext_minor() ida_alloc_range(..., min, max, ...) returns values from min to max, inclusive. So, NR_EXT_DEVT is a valid idx returned by blk_alloc_ext_minor(). This is an issue because in device_add_disk(), this value is used in: ddev->devt = MKDEV(disk->major, disk->first_minor); and NR_EXT_DEVT is '(1 << MINORBITS)'. So, should 'disk->first_minor' be NR_EXT_DEVT, it would overflow.

The advisory is shared at git.kernel.org. This vulnerability is known as CVE-2022-49147 since 02/26/2025. Technical details are known, but no exploit is available.

Upgrading to version 5.15.33, 5.16.19 or 5.17.2 eliminates this vulnerability. Applying the patch 5b9ac3727e4abb11c9cfbe9c0781fc05dfdd7cfb/0f8cf8f5ccbad25ed6828875b222dbab29d5c272/fbe2cc4525480ddd20c866bb5c0578071e01451a/d1868328dec5ae2cf210111025fcbc71f78dd5ca 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 vulnerability database at EUVD (EUVD-2022-55078). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.15.0
• 5.15.1
• 5.15.2
• 5.15.3
• 5.15.4
• 5.15.5
• 5.15.6
• 5.15.7
• 5.15.8
• 5.15.9
• 5.15.10
• 5.15.11
• 5.15.12
• 5.15.13
• 5.15.14
• 5.15.15
• 5.15.16
• 5.15.17
• 5.15.18
• 5.15.19
• 5.15.20
• 5.15.21
• 5.15.22
• 5.15.23
• 5.15.24
• 5.15.25
• 5.15.26
• 5.15.27
• 5.15.28
• 5.15.29
• 5.15.30
• 5.15.31
• 5.15.32
• 5.16.0
• 5.16.1
• 5.16.2
• 5.16.3
• 5.16.4
• 5.16.5
• 5.16.6
• 5.16.7
• 5.16.8
• 5.16.9
• 5.16.10
• 5.16.11
• 5.16.12
• 5.16.13
• 5.16.14
• 5.16.15
• 5.16.16
• 5.16.17
• 5.16.18
• 5.17.0
• 5.17.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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