CVE-2021-46974

2024-02-2719:04:07

Linux

web.nvd.nist.gov

4675

cve-2021-46974

linux kernel

bpf

vulnerability

fix

security update

nvd

AI Score

6.2

Confidence

Low

EPSS

Percentile

10.3%

JSON

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

bpf: Fix masking negation logic upon negative dst register

The negation logic for the case where the off_reg is sitting in the
dst register is not correct given then we cannot just invert the add
to a sub or vice versa. As a fix, perform the final bitwise and-op
unconditionally into AX from the off_reg, then move the pointer from
the src to dst and finally use AX as the source for the original
pointer arithmetic operation such that the inversion yields a correct
result. The single non-AX mov in between is possible given constant
blinding is retaining it as it’s not an immediate based operation.

Affected configurations

Vulners

Node

linuxlinux_kernelRange5.0–4.14.233

linuxlinux_kernelRange4.15.0–4.19.190

linuxlinux_kernelRange4.20.0–5.4.117

linuxlinux_kernelRange5.5.0–5.10.35

linuxlinux_kernelRange5.11.0–5.11.19

linuxlinux_kernelRange5.12.0–5.12.2

linuxlinux_kernelRange5.13.0≥

VendorProductVersionCPE
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Vendor	Product	Version	CPE
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "kernel/bpf/verifier.c"
    ],
    "versions": [
      {
        "version": "ae03b6b1c880",
        "lessThan": "4d542ddb88fb",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "f92a819b4cbe",
        "lessThan": "0e2dfdc74a7f",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "979d63d50c0c",
        "lessThan": "53e0db429b37",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "979d63d50c0c",
        "lessThan": "2cfa537674cd",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "979d63d50c0c",
        "lessThan": "6eba92a4d4be",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "979d63d50c0c",
        "lessThan": "7cf64d8679ca",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "979d63d50c0c",
        "lessThan": "b9b34ddbe207",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "kernel/bpf/verifier.c"
    ],
    "versions": [
      {
        "version": "5.0",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.0",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.14.233",
        "lessThanOrEqual": "4.14.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.190",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.117",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.35",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.11.19",
        "lessThanOrEqual": "5.11.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.12.2",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.13",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]