CVE-2021-47259

2024-05-2115:15:14

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

web.nvd.nist.gov

nfs vulnerability fix

kasan reports

use-after-free

kernel version

mount

nic

server

clear_bit call

refcounting

clp pointer

nfs_put_client

6.7 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.

Affected configurations

Vulners

Node

linuxlinux_kernelRange4.13–4.14.237

linuxlinux_kernelRange4.15.0–4.19.195

linuxlinux_kernelRange4.20.0–5.4.126

linuxlinux_kernelRange5.5.0–5.10.44

linuxlinux_kernelRange5.11.0–5.12.11

linuxlinux_kernelRange5.13.0≥

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"
      }
    ]
  }
]