CVE-2024-26773 ext4: avoid allocating blocks from corrupted group in ext4_mb_try_best_found()
A race condition in the Linux kernel ext4 filesystem allows allocating blocks from a corrupted group, potentially leading to system instability or denial of service.
- 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-2024-26773?
CVE-2024-26773 is a high-severity vulnerability in Debian Debian Linux, published on 3 Apr 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:
ext4: avoid allocating blocks from corrupted group in ext4_mb_try_best_found()
Determine if the group block bitmap is corrupted before using ac_b_ex in ext4_mb_try_best_found() to avoid allocating blocks from a group with a corrupted block bitmap in the following concurrency and making the situation worse.
ext4_mb_regular_allocator ext4_lock_group(sb, group) ext4_mb_good_group // check if the group bbitmap is corrupted ext4_mb_complex_scan_group // Scan group gets ac_b_ex but doesn't use it ext4_unlock_group(sb, group) ext4_mark_group_bitmap_corrupted(group) // The block bitmap was corrupted during // the group unlock gap. ext4_mb_try_best_found ext4_lock_group(ac->ac_sb, group) ext4_mb_use_best_found mb_mark_used // Allocating blocks in block bitmap corrupted group
Which versions are affected by CVE-2024-26773?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2024-26773?
Apply the vendor's patch.
Is CVE-2024-26773 being exploited?
There is no known exploitation of CVE-2024-26773 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2024-26773, DEBIAN-CVE-2024-26773, GHSA-j648-rgv6-ccc8, UBUNTU-CVE-2024-26773.