CVE-2021-47259 NFS: Fix use-after-free in nfs4_init_client()

2024-05-2114:19:52

Linux

github.com

linux kernel

nfs

vulnerability

kasan

use-after-free

mounting

nics

server

patch

refcounting

6.8 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

10.4%

JSON

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

NFS: Fix use-after-free in nfs4_init_client()

KASAN reports a use-after-free when attempting to mount two different
exports through two different NICs that belong to the same server.

Olga was able to hit this with kernels starting somewhere between 5.7
and 5.10, but I traced the patch that introduced the clear_bit() call to
4.13. So something must have changed in the refcounting of the clp
pointer to make this call to nfs_put_client() the very last one.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/nfs/nfs4client.c"
    ],
    "versions": [
      {
        "version": "8dcbec6d20eb",
        "lessThan": "c7eab9e2d7b4",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "8dcbec6d20eb",
        "lessThan": "42c10b0db064",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "8dcbec6d20eb",
        "lessThan": "3e3c7ebbfac1",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "8dcbec6d20eb",
        "lessThan": "c3b6cf64dfe4",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "8dcbec6d20eb",
        "lessThan": "72651c6579a2",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "8dcbec6d20eb",
        "lessThan": "476bdb04c501",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/nfs/nfs4client.c"
    ],
    "versions": [
      {
        "version": "4.13",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "4.13",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.14.237",
        "lessThanOrEqual": "4.14.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.195",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.126",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.44",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.12.11",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.13",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]