CVE-2024-38621 media: stk1160: fix bounds checking in stk1160_copy_video()
A buffer overflow in the stk1160 video driver allows attackers to execute arbitrary code or cause a system crash via crafted video data.
- 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-2024-38621?
CVE-2024-38621 is a high-severity memory corruption vulnerability in Linux kernel, published on 21 Jun 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:
media: stk1160: fix bounds checking in stk1160_copy_video()
The subtract in this condition is reversed. The ->length is the length of the buffer. The ->bytesused is how many bytes we have copied thus far. When the condition is reversed that means the result of the subtraction is always negative but since it's unsigned then the result is a very high positive value. That means the overflow check is never true.
Additionally, the ->bytesused doesn't actually work for this purpose because we're not writing to "buf->mem + buf->bytesused". Instead, the math to calculate the destination where we are writing is a bit involved. You calculate the number of full lines already written, multiply by two, skip a line if necessary so that we start on an odd numbered line, and add the offset into the line.
To fix this buffer overflow, just take the actual destination where we are writing, if the offset is already out of bounds print an error and return. Otherwise, write up to buf->length bytes.
Weakness: CWE-787
Which versions are affected by CVE-2024-38621?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-38621?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2024-38621 being exploited?
There is no known exploitation of CVE-2024-38621 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-38621, DEBIAN-CVE-2024-38621, GHSA-q3h4-pxwf-237f, UBUNTU-CVE-2024-38621.