CVE-2025-68338 net: dsa: microchip: Don't free uninitialized ksz_irq
A use-after-free vulnerability in the Microchip DSA driver allows local attackers to cause a denial of service by triggering an error path that frees uninitialized IRQ resources.
- 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-2025-68338?
CVE-2025-68338 is an use after free vulnerability in Linux, published on 23 Dec 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:
net: dsa: microchip: Don't free uninitialized ksz_irq
If something goes wrong at setup, ksz_irq_free() can be called on uninitialized ksz_irq (for example when ksz_ptp_irq_setup() fails). It leads to freeing uninitialized IRQ numbers and/or domains.
Use dsa_switch_for_each_user_port_continue_reverse() in the error path to iterate only over the fully initialized ports.
Which versions are affected by CVE-2025-68338?
How do I fix CVE-2025-68338?
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-2025-68338 being exploited?
There is no known exploitation of CVE-2025-68338 in the wild and no public exploit code.
Sources
Also known as AZL-72983, BELL-CVE-2025-68338, DEBIAN-CVE-2025-68338, GHSA-4mf7-7hx2-42fv, ROOT-OS-DEBIAN-13-CVE-2025-68338, ROOT-OS-UBUNTU-2404-CVE-2025-68338 and 1 more.