GHSA-6PMM-J8MH-QWGF
Vulnerability from github – Published: 2026-04-13 15:31 – Updated: 2026-04-18 09:30In 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) [...] =======================================================================
{
"affected": [],
"aliases": [
"CVE-2026-31422"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-13T14:16:11Z",
"severity": null
},
"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=======================================================================",
"id": "GHSA-6pmm-j8mh-qwgf",
"modified": "2026-04-18T09:30:20Z",
"published": "2026-04-13T15:31:42Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31422"
},
{
"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"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.