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CVE-2026-53014

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: act_mirred: fix wrong device for mac_header_xmit check in tcf_blockcast_redir In tcf_blockcast_redir(), when iterating block ports to redirect packets to multiple devices, the mac_header_xmit flag is queried from the wrong device. The loop sends to dev_prev but queries dev_is_mac_header_xmit(dev) — which is the NEXT device in the iteration, not the one being sent to. This causes tcf_mirred_to_dev() to make incorrect decisions about whether to push or pull the MAC header. When the block contains mixed device types (e.g., an ethernet veth and a tunnel device), intermediate devices get the wrong mac_header_xmit flag, leading to skb header corruption. In the worst case, skb_push_rcsum with an incorrect mac_len can exhaust headroom and panic. The last device in the loop is handled correctly (line 365-366 uses dev_is_mac_header_xmit(dev_prev)), confirming this is a copy-paste oversight for the intermediate devices. Fix by using dev_prev instead of dev for the mac_header_xmit query, consistent with the device actually being sent to.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-06-24 17:17:12.683000
Last modified
2026-11-06 17:18:01.510000
View original CVE JSON
{
  "id": "CVE-2026-53014",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-06-24T17:17:12.683",
  "lastModified": "2026-11-06T17:18:01.510",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: act_mirred: fix wrong device for mac_header_xmit check in tcf_blockcast_redir\n\nIn tcf_blockcast_redir(), when iterating block ports to redirect\npackets to multiple devices, the mac_header_xmit flag is queried\nfrom the wrong device. The loop sends to dev_prev but queries\ndev_is_mac_header_xmit(dev) — which is the NEXT device in the\niteration, not the one being sent to.\n\nThis causes tcf_mirred_to_dev() to make incorrect decisions about\nwhether to push or pull the MAC header. When the block contains\nmixed device types (e.g., an ethernet veth and a tunnel device),\nintermediate devices get the wrong mac_header_xmit flag, leading to\nskb header corruption. In the worst case, skb_push_rcsum with an\nincorrect mac_len can exhaust headroom and panic.\n\nThe last device in the loop is handled correctly (line 365-366 uses\ndev_is_mac_header_xmit(dev_prev)), confirming this is a copy-paste\noversight for the intermediate devices.\n\nFix by using dev_prev instead of dev for the mac_header_xmit query,\nconsistent with the device actually being sent to."
    }
  ],
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          "baseSeverity": "MEDIUM",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
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