CVE-2023-52566 nilfs2: fix potential use after free in nilfs_gccache_submit_read_data()
A use-after-free vulnerability in the Linux kernel nilfs2 filesystem allows local attackers to potentially execute code or escalate privileges by triggering a specific garbage collection path.
- 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-2023-52566?
CVE-2023-52566 is a medium-severity use after free vulnerability in Linux kernel, published on 2 Mar 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:
nilfs2: fix potential use after free in nilfs_gccache_submit_read_data()
In nilfs_gccache_submit_read_data(), brelse(bh) is called to drop the reference count of bh when the call to nilfs_dat_translate() fails. If the reference count hits 0 and its owner page gets unlocked, bh may be freed. However, bh->b_page is dereferenced to put the page after that, which may result in a use-after-free bug. This patch moves the release operation after unlocking and putting the page.
NOTE: The function in question is only called in GC, and in combination with current userland tools, address translation using DAT does not occur in that function, so the code path that causes this issue will not be executed. However, it is possible to run that code path by intentionally modifying the userland GC library or by calling the GC ioctl directly.
[[email protected]: NOTE added to the commit log]
Weakness: CWE-416
Which versions are affected by CVE-2023-52566?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-52566?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2023-52566 being exploited?
There is no known exploitation of CVE-2023-52566 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2023-52566, DEBIAN-CVE-2023-52566, GHSA-4c64-w6qg-97qw, UBUNTU-CVE-2023-52566.