CVE-2026-97605 erofs: preserve LZMA decoders on resize failure
A null pointer dereference in the Linux kernel's EROFS LZMA decoder allows local attackers to cause a denial of service via mount operations.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-97605?
CVE-2026-97605 is a vulnerability in Linux, published on 25 Sep 2026. 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:
erofs: preserve LZMA decoders on resize failure
The pool-resize path frees each stream's old decoder before allocating its replacement. If an allocation fails after some streams have already been replaced, the failed stream is put back on the list with state == NULL. z_erofs_lzma_max_dictsize is still advanced as if the whole pool had been resized.
An existing LZMA mount can select the broken stream and pass NULL to xz_dec_microlzma_reset(). A retry at the same size also skip another resize attempt. Since the global maximum was advanced, thus, the invalid state is left unrepaired.
Allocate each replacement before freeing the old decoder, temporarily retaining one old decoder during allocation. Stop at the first failure and advance z_erofs_lzma_max_dictsize only after all streams satisfy the request.
Record each stream's dictionary capacity so retries can skip streams already enlarged before a partial failure.
Which versions are affected by CVE-2026-97605?
How do I fix CVE-2026-97605?
Apply the vendor's patch.
Is CVE-2026-97605 being exploited?
There is no known exploitation of CVE-2026-97605 in the wild and no public exploit code.
Sources
Also known as AZL-104309, BELL-CVE-2026-97605, DEBIAN-CVE-2026-97605, GHSA-8cg5-7hqp-6rcp, UBUNTU-CVE-2026-97605.