CVE-2022-49147 block: Fix the maximum minor value is blk_alloc_ext_minor()

What is CVE-2022-49147?

CVE-2022-49147 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

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.

Which versions are affected by CVE-2022-49147?

It affects 1 product.

Products include Linux kernel.

How do I fix CVE-2022-49147?

Apply the vendor's patch.

Is CVE-2022-49147 being exploited?

There is no known exploitation of CVE-2022-49147 in the wild and no public exploit code.

Other vulnerabilities in Linux kernel

• CVE-2026-53266 Linux Kernel Out-of-Bounds Write Exploited High 8.8
• CVE-2013-6282 Linux Kernel Improper Input Validation Exploited High 8.8
• CVE-2022-0185 Linux Kernel Heap-Based Buffer Overflow Exploited High 8.4
• CVE-2013-2094 Linux Kernel Privilege Escalation Exploited High 8.4
• CVE-2026-53362 Linux Kernel Unspecified Exploited High 7.8

All Linux kernel vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as DEBIAN-CVE-2022-49147, GHSA-3mph-xfrg-5928, UBUNTU-CVE-2022-49147.