CVE-2024-40984 ACPICA: Revert "ACPICA: avoid Info: mapping multiple BARs. Your kernel is fine."
A NULL pointer dereference in the Linux kernel ACPICA component can cause a system crash when mapping operation regions across page boundaries.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2024-40984?
CVE-2024-40984 is a high-severity vulnerability in Linux kernel, published on 12 Jul 2024. 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:
ACPICA: Revert "ACPICA: avoid Info: mapping multiple BARs. Your kernel is fine."
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.
Weakness: CWE-476
Which versions are affected by CVE-2024-40984?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-40984?
Apply the vendor's patch.
Is CVE-2024-40984 being exploited?
There is no known exploitation of CVE-2024-40984 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-40984, DEBIAN-CVE-2024-40984, GHSA-j2gx-qfwv-h2pp, UBUNTU-CVE-2024-40984.