CVE-2022-49147

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux22ae8ce8b89241c94ac00c237752c0ffa37ba5ae < 5b9ac3727e4abb11c9cfbe9c0781fc05dfdd7cfbaffected
LinuxLinux22ae8ce8b89241c94ac00c237752c0ffa37ba5ae < 0f8cf8f5ccbad25ed6828875b222dbab29d5c272affected
LinuxLinux22ae8ce8b89241c94ac00c237752c0ffa37ba5ae < fbe2cc4525480ddd20c866bb5c0578071e01451aaffected
LinuxLinux22ae8ce8b89241c94ac00c237752c0ffa37ba5ae < d1868328dec5ae2cf210111025fcbc71f78dd5caaffected
LinuxLinux5.11affected
LinuxLinux0 < 5.11unaffected
LinuxLinux5.15.33 <= 5.15.*unaffected
LinuxLinux5.16.19 <= 5.16.*unaffected
LinuxLinux5.17.2 <= 5.17.*unaffected
LinuxLinux5.18 <= *unaffected

Weaknesses

References