CVE-2024-46744 Squashfs: sanity check symbolic link size
A corrupted Squashfs symbolic link size causes an integer overflow, leading to uninitialized memory access and potential denial of service in the Linux kernel.
- 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-2024-46744?
CVE-2024-46744 is a high-severity vulnerability in Linux kernel, published on 18 Sep 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: sanity check symbolic link size
Syzkiller reports a "KMSAN: uninit-value in pick_link" bug.
This is caused by an uninitialised page, which is ultimately caused by a corrupted symbolic link size read from disk.
The reason why the corrupted symlink size causes an uninitialised page is due to the following sequence of events:
1. squashfs_read_inode() is called to read the symbolic link from disk. This assigns the corrupted value 3875536935 to inode->i_size.
2. Later squashfs_symlink_read_folio() is called, which assigns this corrupted value to the length variable, which being a signed int, overflows producing a negative number.
3. The following loop that fills in the page contents checks that the copied bytes is less than length, which being negative means the loop is skipped, producing an uninitialised page.
This patch adds a sanity check which checks that the symbolic link size is not larger than expected.
--
V2: fix spelling mistake.
Weakness: CWE-59
Which versions are affected by CVE-2024-46744?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-46744?
Apply the vendor's patch.
Is CVE-2024-46744 being exploited?
There is no known exploitation of CVE-2024-46744 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-49764, BELL-CVE-2024-46744, DEBIAN-CVE-2024-46744, GHSA-fxvq-h88x-3jfr, UBUNTU-CVE-2024-46744.