CVE-2025-39854 ice: fix NULL access of tx->in_use in ice_ll_ts_intr
A missing initialization check in the Intel E810 network driver allows attackers to trigger a null pointer dereference, causing a system crash.
- 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-2025-39854?
CVE-2025-39854 is a high-severity vulnerability in Linux kernel, published on 19 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:
ice: fix NULL access of tx->in_use in ice_ll_ts_intr
Recent versions of the E810 firmware have support for an extra interrupt to handle report of the "low latency" Tx timestamps coming from the specialized low latency firmware interface. Instead of polling the registers, software can wait until the low latency interrupt is fired.
This logic makes use of the Tx timestamp tracking structure, ice_ptp_tx, as it uses the same "ready" bitmap to track which Tx timestamps complete.
Unfortunately, the ice_ll_ts_intr() function does not check if the tracker is initialized before its first access. This results in NULL dereference or use-after-free bugs similar to the issues fixed in the ice_ptp_ts_irq() function.
Fix this by only checking the in_use bitmap (and other fields) if the tracker is marked as initialized. The reset flow will clear the init field under lock before it tears the tracker down, thus preventing any use-after-free or NULL access.
Weakness: CWE-416
Which versions are affected by CVE-2025-39854?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-39854?
Apply the vendor's patch.
Is CVE-2025-39854 being exploited?
There is no known exploitation of CVE-2025-39854 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-39854, DEBIAN-CVE-2025-39854, GHSA-6fhv-p8f6-8rjf, ROOT-OS-DEBIAN-13-CVE-2025-39854, ROOT-OS-UBUNTU-2404-CVE-2025-39854, UBUNTU-CVE-2025-39854.