CVE-2024-26884 bpf: Fix hashtab overflow check on 32-bit arches
An integer overflow in the Linux kernel BPF hashtab code on 32-bit architectures can lead to undefined behavior and potential denial of service.
- 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-2024-26884?
CVE-2024-26884 is a high-severity vulnerability in Linux kernel, published on 17 Apr 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:
bpf: Fix hashtab overflow check on 32-bit arches
The hashtab code relies on roundup_pow_of_two() to compute the number of hash buckets, and contains an overflow check by checking if the resulting value is 0. However, on 32-bit arches, the roundup code itself can overflow by doing a 32-bit left-shift of an unsigned long value, which is undefined behaviour, so it is not guaranteed to truncate neatly. This was triggered by syzbot on the DEVMAP_HASH type, which contains the same check, copied from the hashtab code. So apply the same fix to hashtab, by moving the overflow check to before the roundup.
Which versions are affected by CVE-2024-26884?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-26884?
Apply the vendor's patch.
Is CVE-2024-26884 being exploited?
There is no known exploitation of CVE-2024-26884 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-40103, BELL-CVE-2024-26884, DEBIAN-CVE-2024-26884, GHSA-8p54-55f6-pg9j, UBUNTU-CVE-2024-26884.