CVE-2023-52676 bpf: Guard stack limits against 32bit overflow
Integer overflow in Linux kernel BPF verifier stack limit checks allows attackers to bypass bounds, potentially leading to code execution or privilege escalation.
- 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-2023-52676?
CVE-2023-52676 is a high-severity vulnerability in Linux kernel, published on 17 May 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: Guard stack limits against 32bit overflow
This patch promotes the arithmetic around checking stack bounds to be done in the 64-bit domain, instead of the current 32bit. The arithmetic implies adding together a 64-bit register with a int offset. The register was checked to be below 1<<29 when it was variable, but not when it was fixed. The offset either comes from an instruction (in which case it is 16 bit), from another register (in which case the caller checked it to be below 1<<29 [1]), or from the size of an argument to a kfunc (in which case it can be a u32 [2]). Between the register being inconsistently checked to be below 1<<29, and the offset being up to an u32, it appears that we were open to overflowing the `int`s which were currently used for arithmetic.
[1] https://github.com/torvalds/linux/blob/815fb87b753055df2d9e50f6cd80eb10235fe3e9/kernel/bpf/verifier.c#L7494-L7498 [2] https://github.com/torvalds/linux/blob/815fb87b753055df2d9e50f6cd80eb10235fe3e9/kernel/bpf/verifier.c#L11904
Weakness: CWE-190
Which versions are affected by CVE-2023-52676?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-52676?
Apply the vendor's patch.
Is CVE-2023-52676 being exploited?
There is no known exploitation of CVE-2023-52676 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-67731, BELL-CVE-2023-52676, DEBIAN-CVE-2023-52676, GHSA-x25x-hhpj-pjqp, ROOT-OS-DEBIAN-11-CVE-2023-52676, ROOT-OS-DEBIAN-12-CVE-2023-52676 and 2 more.