CVE-2021-47520 can: pch_can: pch_can_rx_normal: fix use after free

2024-05-2415:09:33

Linux

github.com

linux kernel

vulnerability resolved

can_frame

netif_receive_skb

skb

use after free

pch_can

AI Score

6.9

Confidence

Low

EPSS

Percentile

5.1%

SSVC

Exploitation

none

Automatable

Technical Impact

partial

JSON

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

can: pch_can: pch_can_rx_normal: fix use after free

After calling netif_receive_skb(skb), dereferencing skb is unsafe.
Especially, the can_frame cf which aliases skb memory is dereferenced
just after the call netif_receive_skb(skb).

Reordering the lines solves the issue.

CNA Affected

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "b21d18b51b31",
        "lessThan": "bafe343a885c",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b21d18b51b31",
        "lessThan": "3a3c46e2eff0",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b21d18b51b31",
        "lessThan": "affbad02bf80",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b21d18b51b31",
        "lessThan": "3e193ef4e0a3",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b21d18b51b31",
        "lessThan": "abb4eff3dcd2",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b21d18b51b31",
        "lessThan": "703dde112021",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b21d18b51b31",
        "lessThan": "6c73fc931658",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b21d18b51b31",
        "lessThan": "94cddf1e9227",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/net/can/pch_can.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "2.6.37"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "2.6.37",
        "versionType": "custom"
      },
      {
        "status": "unaffected",
        "version": "4.4.295",
        "versionType": "custom",
        "lessThanOrEqual": "4.4.*"
      },
      {
        "status": "unaffected",
        "version": "4.9.293",
        "versionType": "custom",
        "lessThanOrEqual": "4.9.*"
      },
      {
        "status": "unaffected",
        "version": "4.14.258",
        "versionType": "custom",
        "lessThanOrEqual": "4.14.*"
      },
      {
        "status": "unaffected",
        "version": "4.19.221",
        "versionType": "custom",
        "lessThanOrEqual": "4.19.*"
      },
      {
        "status": "unaffected",
        "version": "5.4.165",
        "versionType": "custom",
        "lessThanOrEqual": "5.4.*"
      },
      {
        "status": "unaffected",
        "version": "5.10.85",
        "versionType": "custom",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.8",
        "versionType": "custom",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "5.16",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/net/can/pch_can.c"
    ],
    "defaultStatus": "affected"
  }
]