CVE-2026-98028eth: nfp: drop the replaced rule from the list when reprogramming fails

Official description

In the Linux kernel, the following vulnerability has been resolved: eth: nfp: drop the replaced rule from the list when reprogramming fails nfp_net_fs_add() replaces an existing rule by deleting it from the hardware, decrementing nn->fs.count and programming the new one. If nfp_net_fs_add_hw() fails the old entry stays on nn->fs.list - only the success path reaches list_replace() - so the list is one longer than nn->fs.count, and it advertises a rule whose hardware entry has already been torn down. nn->fs.count is what ETHTOOL_GRXCLSRLCNT reports, so userspace then sizes its buffer one entry short of what the GRXCLSRLALL walk wants to write. That used to overwrite one u32 past the allocation; since the walk is bounded it is a permanent -EMSGSIZE instead, as nothing ever resyncs the counter.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/603b70093f729f52a37544b48679903cad834856
• https://git.kernel.org/stable/c/edaec279f59f801a05b751df475ed71a0a68c88a
• https://git.kernel.org/stable/c/552e528a7d85cbe088b2ae4f78194713975b46cf
• https://git.kernel.org/stable/c/108bb2142e3a12c9ad625ad662973127a113ddc6