{"id":"CVE-2026-31422","summary":"net/sched: cls_flow: fix NULL pointer dereference on shared blocks","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: cls_flow: fix NULL pointer dereference on shared blocks\n\nflow_change() calls tcf_block_q() and dereferences q-\u003ehandle to derive\na default baseclass.  Shared blocks leave block-\u003eq NULL, causing a NULL\nderef when a flow filter without a fully qualified baseclass is created\non a shared block.\n\nCheck tcf_block_shared() before accessing block-\u003eq and return -EINVAL\nfor shared blocks.  This avoids the null-deref shown below:\n\n=======================================================================\nKASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]\nRIP: 0010:flow_change (net/sched/cls_flow.c:508)\nCall Trace:\n tc_new_tfilter (net/sched/cls_api.c:2432)\n rtnetlink_rcv_msg (net/core/rtnetlink.c:6980)\n [...]\n=======================================================================","modified":"2026-06-18T03:54:32.369518125Z","published":"2026-04-13T13:40:25.911Z","related":["SUSE-SU-2026:2068-1","SUSE-SU-2026:21841-1","SUSE-SU-2026:21845-1","SUSE-SU-2026:21860-1","SUSE-SU-2026:21876-1","SUSE-SU-2026:21877-1","SUSE-SU-2026:21916-1","SUSE-SU-2026:21919-1","SUSE-SU-2026:2217-1","SUSE-SU-2026:2238-1","openSUSE-SU-2026:20826-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31422.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/1a280dd4bd1d616a01d6ffe0de284c907b555504"},{"type":"WEB","url":"https://git.kernel.org/stable/c/415ea0c973c754b9f375225807810eb9045f4293"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4a09f72007201c9f667dc47f64517ec23eea65e5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/57f94ac7e953eece5ed4819605a18f3cdfc63dcc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/942813276edeb1741fa5b0a73471beb4e495fa08"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9bf5fc36a43f7b8b5507c96e74fb81f1e8b4957e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a208c3e1232997e9317887294c20008dfcb75449"},{"type":"WEB","url":"https://git.kernel.org/stable/c/cc707a4fd4c3b6ab2722e06bc359aa010e13d408"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/31xxx/CVE-2026-31422.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31422"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"1abf272022cf1d18469405f47b4ec49c6a3125db"},{"fixed":"57f94ac7e953eece5ed4819605a18f3cdfc63dcc"},{"fixed":"942813276edeb1741fa5b0a73471beb4e495fa08"},{"fixed":"cc707a4fd4c3b6ab2722e06bc359aa010e13d408"},{"fixed":"4a09f72007201c9f667dc47f64517ec23eea65e5"},{"fixed":"9bf5fc36a43f7b8b5507c96e74fb81f1e8b4957e"},{"fixed":"a208c3e1232997e9317887294c20008dfcb75449"},{"fixed":"415ea0c973c754b9f375225807810eb9045f4293"},{"fixed":"1a280dd4bd1d616a01d6ffe0de284c907b555504"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31422.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.15.0"},{"fixed":"5.10.253"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.203"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.168"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.134"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.81"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.22"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.12"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-31422.json"}}],"schema_version":"1.7.5"}