CVE-2025-21894 net: enetc: VFs do not support HWTSTAMP_TX_ONESTEP_SYNC
A null pointer dereference in the ENETC network driver causes a kernel crash when VFs attempt one-step timestamping, leading to 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-2025-21894?
CVE-2025-21894 is a medium-severity vulnerability in Linux kernel, published on 1 Apr 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: enetc: VFs do not support HWTSTAMP_TX_ONESTEP_SYNC
Actually ENETC VFs do not support HWTSTAMP_TX_ONESTEP_SYNC because only ENETC PF can access PMa_SINGLE_STEP registers. And there will be a crash if VFs are used to test one-step timestamp, the crash log as follows.
[ 129.110909] Unable to handle kernel paging request at virtual address 00000000000080c0 [ 129.287769] Call trace: [ 129.290219] enetc_port_mac_wr+0x30/0xec (P) [ 129.294504] enetc_start_xmit+0xda4/0xe74 [ 129.298525] enetc_xmit+0x70/0xec [ 129.301848] dev_hard_start_xmit+0x98/0x118
Which versions are affected by CVE-2025-21894?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2025-21894?
Apply the vendor's patch.
Is CVE-2025-21894 being exploited?
There is no known exploitation of CVE-2025-21894 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2025-21894, DEBIAN-CVE-2025-21894, GHSA-m7gq-vr78-836g, ROOT-OS-DEBIAN-11-CVE-2025-21894, ROOT-OS-DEBIAN-12-CVE-2025-21894, ROOT-OS-UBUNTU-2204-CVE-2025-21894 and 2 more.