CVE-2024-26739 net/sched: act_mirred: don't override retval if we already lost the skb

2024-04-0317:00:24

Linux

www.cve.org

linux kernel

vulnerability

fix

net/sched

act_mirred

AI Score

7.5

Confidence

High

EPSS

Percentile

15.5%

JSON

In the Linux kernel, the following vulnerability has been resolved:

net/sched: act_mirred: don’t override retval if we already lost the skb

If we’re redirecting the skb, and haven’t called tcf_mirred_forward(),
yet, we need to tell the core to drop the skb by setting the retcode
to SHOT. If we have called tcf_mirred_forward(), however, the skb
is out of our hands and returning SHOT will lead to UaF.

Move the retval override to the error path which actually need it.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/sched/act_mirred.c"
    ],
    "versions": [
      {
        "version": "e5cf1baf92cb",
        "lessThan": "28cdbbd38a44",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "e5cf1baf92cb",
        "lessThan": "f4e294bbdca8",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "e5cf1baf92cb",
        "lessThan": "166c2c8a6a4d",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "net/sched/act_mirred.c"
    ],
    "versions": [
      {
        "version": "4.19",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "4.19",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.6.19",
        "lessThanOrEqual": "6.6.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.7.7",
        "lessThanOrEqual": "6.7.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]