CVE-2022-50286 ext4: fix delayed allocation bug in ext4_clu_mapped for bigalloc + inline
A bug in the Linux kernel ext4 filesystem can cause kernel panics and memory leaks when using bigalloc and inline data options.
- 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-2022-50286?
CVE-2022-50286 is a high-severity memory corruption vulnerability in Linux kernel, published on 15 Sep 2025. 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: fix delayed allocation bug in ext4_clu_mapped for bigalloc + inline
When converting files with inline data to extents, delayed allocations made on a file system created with both the bigalloc and inline options can result in invalid extent status cache content, incorrect reserved cluster counts, kernel memory leaks, and potential kernel panics.
With bigalloc, the code that determines whether a block must be delayed allocated searches the extent tree to see if that block maps to a previously allocated cluster. If not, the block is delayed allocated, and otherwise, it isn't. However, if the inline option is also used, and if the file containing the block is marked as able to store data inline, there isn't a valid extent tree associated with the file. The current code in ext4_clu_mapped() calls ext4_find_extent() to search the non-existent tree for a previously allocated cluster anyway, which typically finds nothing, as desired. However, a side effect of the search can be to cache invalid content from the non-existent tree (garbage) in the extent status tree, including bogus entries in the pending reservation tree.
To fix this, avoid searching the extent tree when allocating blocks for bigalloc + inline files that are being converted from inline to extent mapped.
Which versions are affected by CVE-2022-50286?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50286?
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-2022-50286 being exploited?
There is no known exploitation of CVE-2022-50286 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50286, GHSA-r6cc-hxch-c8pj, UBUNTU-CVE-2022-50286.