CVE-2024-40984 Information

Description

In the Linux kernel the following vulnerability has been resolved:

ACPICA: Revert \ACPICA: avoid Info: mapping multiple BARs. Your kernel is fine.\n Undo the modifications made in commit d410ee5109a1 (\ACPICA: avoid \Info: mapping multiple BARs. Your kernel is fine.). The initial purpose of this commit was to stop memory mappings for operation regions from overlapping page boundaries as it can trigger warnings if different page attributes are present.

However it was found that when this situation arises mapping continues until the boundary’s end but there is still an attempt to read/write the entire length of the map leading to a NULL pointer deference. For example if a four-byte mapping request is made but only one byte is mapped because it hits the current page boundary’s end a four-byte read/write attempt is still made resulting in a NULL pointer deference.

Instead map the entire length as the ACPI specification does not mandate that it must be within the same page boundary. It is permissible for it to be mapped across different regions.

Reference

https://git.kernel.org/stable/c/435ecc978c3d5d0c4e172ec5b956dc1904061d98 https://git.kernel.org/stable/c/ae465109d82f4fb03c5adbe85f2d6a6a3d59124c https://git.kernel.org/stable/c/6eca23100e9030725f69c1babacd58803f29ec8d https://git.kernel.org/stable/c/dc5017c57f5eee80020c73ff8b67ba7f9fd08b1f https://git.kernel.org/stable/c/ddc1f5f124479360a1fd43f73be950781d172239 https://git.kernel.org/stable/c/434c6b924e1f4c219aab2d9e05fe79c5364e37d3 https://git.kernel.org/stable/c/e21a4c9129c72fa54dd00f5ebf71219b41d43c04 https://git.kernel.org/stable/c/a83e1385b780d41307433ddbc86e3c528db031f0