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CVE-2026-43238

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_skbedit: fix divide-by-zero in tcf_skbedit_hash() Commit 38a6f0865796 ("net: sched: support hash selecting tx queue") added SKBEDIT_F_TXQ_SKBHASH support. The inclusive range size is computed as: mapping_mod = queue_mapping_max - queue_mapping + 1; The range size can be 65536 when the requested range covers all possible u16 queue IDs (e.g. queue_mapping=0 and queue_mapping_max=U16_MAX). That value cannot be represented in a u16 and previously wrapped to 0, so tcf_skbedit_hash() could trigger a divide-by-zero: queue_mapping += skb_get_hash(skb) % params->mapping_mod; Compute mapping_mod in a wider type and reject ranges larger than U16_MAX to prevent params->mapping_mod from becoming 0 and avoid the crash.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-05-06 12:16:44.093000
Last modified
2026-11-06 16:18:28.887000
View original CVE JSON 
{
  "id": "CVE-2026-43238",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-05-06T12:16:44.093",
  "lastModified": "2026-11-06T16:18:28.887",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_skbedit: fix divide-by-zero in tcf_skbedit_hash()\n\nCommit 38a6f0865796 (\"net: sched: support hash selecting tx queue\")\nadded SKBEDIT_F_TXQ_SKBHASH support. The inclusive range size is\ncomputed as:\n\nmapping_mod = queue_mapping_max - queue_mapping + 1;\n\nThe range size can be 65536 when the requested range covers all possible\nu16 queue IDs (e.g. queue_mapping=0 and queue_mapping_max=U16_MAX).\nThat value cannot be represented in a u16 and previously wrapped to 0,\nso tcf_skbedit_hash() could trigger a divide-by-zero:\n\nqueue_mapping += skb_get_hash(skb) % params->mapping_mod;\n\nCompute mapping_mod in a wider type and reject ranges larger than U16_MAX\nto prevent params->mapping_mod from becoming 0 and avoid the crash."
    }
  ],
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      "affectedData": [
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              "versionType": "original_commit_for_fix",
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  ],
  "metrics": {
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          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
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  "weaknesses": [
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      "source": "[email protected]",
      "type": "Primary",
      "description": [
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          "value": "CWE-369"
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}