FKIE_CVE-2026-31422

Vulnerability from fkie_nvd - Published: 2026-04-13 14:16 - Updated: 2026-04-18 09:16
Severity ?
Summary
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) [...] =======================================================================
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1a280dd4bd1d616a01d6ffe0de284c907b555504
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/415ea0c973c754b9f375225807810eb9045f4293
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/4a09f72007201c9f667dc47f64517ec23eea65e5
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/57f94ac7e953eece5ed4819605a18f3cdfc63dcc
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/942813276edeb1741fa5b0a73471beb4e495fa08
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9bf5fc36a43f7b8b5507c96e74fb81f1e8b4957e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a208c3e1232997e9317887294c20008dfcb75449
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cc707a4fd4c3b6ab2722e06bc359aa010e13d408
Impacted products
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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": "CVE-2026-31422",
  "lastModified": "2026-04-18T09:16:32.090",
  "metrics": {},
  "published": "2026-04-13T14:16:11.907",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1a280dd4bd1d616a01d6ffe0de284c907b555504"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/415ea0c973c754b9f375225807810eb9045f4293"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/4a09f72007201c9f667dc47f64517ec23eea65e5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/57f94ac7e953eece5ed4819605a18f3cdfc63dcc"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/942813276edeb1741fa5b0a73471beb4e495fa08"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9bf5fc36a43f7b8b5507c96e74fb81f1e8b4957e"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a208c3e1232997e9317887294c20008dfcb75449"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cc707a4fd4c3b6ab2722e06bc359aa010e13d408"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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