CVE-2026-98029 eth: nfp: bound the ntuple rule dump by the caller's buffer size
A local user can cause a kernel crash by triggering a null pointer dereference in the NFP network driver when dumping flow steering rules with a zero-sized buffer.
- 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-2026-98029?
CVE-2026-98029 is a high-severity 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:
eth: nfp: bound the ntuple rule dump by the caller's buffer size
nfp_net_get_fs_loc() dumps every entry of nn->fs.list into rule_locs[] without consulting cmd->rule_cnt, which is how many entries the caller had room for. ETHTOOL_GRXCLSRLALL requires no CAP_NET_ADMIN and the ioctl sizes the buffer from the rule_cnt userspace passes in, so once an admin has installed flow steering rules any user can ask for fewer slots than there are rules and run off the end of the allocation. A rule_cnt of 0 leaves the buffer pointer NULL and the walk dereferences it.
Bail out with -EMSGSIZE when the buffer fills up, the way the other ntuple capable drivers do, and report how many locations were filled so a shrinking rule list does not leave the caller reading stale slots.
Which versions are affected by CVE-2026-98029?
How do I fix CVE-2026-98029?
Apply the vendor's patch.
Is CVE-2026-98029 being exploited?
There is no known exploitation of CVE-2026-98029 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2026-98029, DEBIAN-CVE-2026-98029, GHSA-q4vw-6vrx-f5xg, UBUNTU-CVE-2026-98029.