CVE-2026-99066

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: can: dev: init_can_skb(): restore skb header initialization Commit 9f10374bb024 ("can: remove private CAN skb headroom infrastructure") removed the skb_reset_mac_header()/skb_reset_network_header()/ skb_reset_transport_header() calls from init_can_skb(). As a result, RX skbs from alloc_can_skb() and friends again carry mac_header = 0xFFFF. When such an skb reaches packet_rcv_spkt() (SOCK_PACKET), the push length calculation overflows and triggers skb_under_panic -> kernel BUG -> full machine panic. The same issue was originally reported in 2014 on linux-can and fixed by commit 969439016d2c ("can: add missing initialisations in CAN related skbuffs"). packet_rcv_spkt() itself has never been hardened: only packet_rcv() and tpacket_rcv() gained dev_has_header() checks in commit d549699048b4 ("net/packet: fix packet receive on L3 devices without visible hard header").

Severity

Not scored

CVSS score

Not available

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-10-23 13:17:30.477000

Last modified

2026-10-23 13:17:30.477000

View original CVE JSON

{
  "id": "CVE-2026-99066",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-10-23T13:17:30.477",
  "lastModified": "2026-10-23T13:17:30.477",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: dev: init_can_skb(): restore skb header initialization\n\nCommit 9f10374bb024 (\"can: remove private CAN skb headroom infrastructure\")\nremoved the skb_reset_mac_header()/skb_reset_network_header()/\nskb_reset_transport_header() calls from init_can_skb(). As a result, RX\nskbs from alloc_can_skb() and friends again carry mac_header = 0xFFFF.\nWhen such an skb reaches packet_rcv_spkt() (SOCK_PACKET), the push length\ncalculation overflows and triggers skb_under_panic -> kernel BUG -> full\nmachine panic.\n\nThe same issue was originally reported in 2014 on linux-can and fixed by\ncommit 969439016d2c (\"can: add missing initialisations in CAN related\nskbuffs\"). packet_rcv_spkt() itself has never been hardened: only\npacket_rcv() and tpacket_rcv() gained dev_has_header() checks in\ncommit d549699048b4 (\"net/packet: fix packet receive on L3 devices\nwithout visible hard header\")."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/net/can/dev/skb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "9f10374bb024593a611e6845847f0444841a231b",
              "lessThan": "8078375dfd0baecd9f1b7b06bb2d6f88d7cb8632",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "9f10374bb024593a611e6845847f0444841a231b",
              "lessThan": "0a04c0cb8606ff88399489d03ef255afe90d0d5f",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/net/can/dev/skb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "7.0",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "7.0",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.11",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {},
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0a04c0cb8606ff88399489d03ef255afe90d0d5f",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/8078375dfd0baecd9f1b7b06bb2d6f88d7cb8632",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}