CVE-2026-31422

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_flow: fix NULL pointer dereference on shared blocks flow_change() calls tcf_block_q() and dereferences q->handle to derive a default baseclass. Shared blocks leave block->q NULL, causing a NULL deref when a flow filter without a fully qualified baseclass is created on a shared block. Check tcf_block_shared() before accessing block->q and return -EINVAL for shared blocks. This avoids the null-deref shown below: ======================================================================= KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:flow_change (net/sched/cls_flow.c:508) Call Trace: tc_new_tfilter (net/sched/cls_api.c:2432) rtnetlink_rcv_msg (net/core/rtnetlink.c:6980) [...] =======================================================================

The following products are affected by CVE-2026-31422 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2026-31422.

URL	Resource
https://git.kernel.org/stable/c/1a280dd4bd1d616a01d6ffe0de284c907b555504
https://git.kernel.org/stable/c/415ea0c973c754b9f375225807810eb9045f4293
https://git.kernel.org/stable/c/4a09f72007201c9f667dc47f64517ec23eea65e5
https://git.kernel.org/stable/c/57f94ac7e953eece5ed4819605a18f3cdfc63dcc
https://git.kernel.org/stable/c/942813276edeb1741fa5b0a73471beb4e495fa08
https://git.kernel.org/stable/c/9bf5fc36a43f7b8b5507c96e74fb81f1e8b4957e
https://git.kernel.org/stable/c/a208c3e1232997e9317887294c20008dfcb75449
https://git.kernel.org/stable/c/cc707a4fd4c3b6ab2722e06bc359aa010e13d408
https://lore.kernel.org/linux-cve-announce/2026041356-CVE-2026-31422-04eb@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2026-31422
https://www.cve.org/CVERecord?id=CVE-2026-31422