CVE-2026-31421

CVE-2026-31421 – Linux kernel net/sched cls_fw NULL pointer dereference . Root cause: in fw_classify(), the old-method path uses tcf_block_q() and dereferences q->handle; for shared blocks, block->q is NULL, causing a NULL pointer dereference when a nonzero skb is classified. The fix preven...

CVE-2026-31421

In the Linux kernel, the following vulnerability has been resolved: net/sched: clsfw: fix NULL pointer dereference on shared blocks The old-method path in fwclassify calls tcfblockq and dereferences q-handle. Shared blocks leave block-q NULL, causing a NULL deref when an empty clsfw filter is...

PT-2023-4446

Name of the Vulnerable Software and Affected Versions Linux kernel affected versions not specified Description The issue is related to a use-after-free flaw in the Linux kernel's net/sched component, specifically in the classifiers cls fw, cls u32, and cls route. This flaw can be exploited by a...