CVE-2024-26982 Squashfs: check the inode number is not the invalid value of zero
A missing check for invalid inode numbers in the Linux kernel's Squashfs driver allows out-of-bounds memory access, potentially causing crashes or data leaks.
- 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-2024-26982?
CVE-2024-26982 is a high-severity memory corruption vulnerability in Linux kernel, published on 1 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:
Squashfs: check the inode number is not the invalid value of zero
Syskiller has produced an out of bounds access in fill_meta_index().
That out of bounds access is ultimately caused because the inode has an inode number with the invalid value of zero, which was not checked.
The reason this causes the out of bounds access is due to following sequence of events:
1. Fill_meta_index() is called to allocate (via empty_meta_index()) and fill a metadata index. It however suffers a data read error and aborts, invalidating the newly returned empty metadata index. It does this by setting the inode number of the index to zero, which means unused (zero is not a valid inode number).
2. When fill_meta_index() is subsequently called again on another read operation, locate_meta_index() returns the previous index because it matches the inode number of 0. Because this index has been returned it is expected to have been filled, and because it hasn't been, an out of bounds access is performed.
This patch adds a sanity check which checks that the inode number is not zero when the inode is created and returns -EINVAL if it is.
[phillip@squashfs.org.uk: whitespace fix]
Weakness: CWE-125
Which versions are affected by CVE-2024-26982?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-26982?
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-2024-26982 being exploited?
There is no known exploitation of CVE-2024-26982 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-57731, BELL-CVE-2024-26982, DEBIAN-CVE-2024-26982, GHSA-8jh7-gcv4-cq6q, UBUNTU-CVE-2024-26982.