Lucene search

416baaa9-dc9f-4396-8d5f-8c081fb06d67CVE-2021-46935

HistoryFeb 27, 2024 - 10:15 a.m.

CVE-2021-46935

2024-02-2710:15:07

CWE-668

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

web.nvd.nist.gov

533

linux kernel

vulnerability

fix

binder

async_free_space

cve-2021-46935

nvd

5.5 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

NONE

Availability Impact

NONE

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

6.5 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

10.4%

JSON

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

binder: fix async_free_space accounting for empty parcels

In 4.13, commit 74310e06be4d (“android: binder: Move buffer out of area shared with user space”)
fixed a kernel structure visibility issue. As part of that patch,
sizeof(void *) was used as the buffer size for 0-length data payloads so
the driver could detect abusive clients sending 0-length asynchronous
transactions to a server by enforcing limits on async_free_size.

Unfortunately, on the “free” side, the accounting of async_free_space
did not add the sizeof(void *) back. The result was that up to 8-bytes of
async_free_space were leaked on every async transaction of 8-bytes or
less. These small transactions are uncommon, so this accounting issue
has gone undetected for several years.

The fix is to use “buffer_size” (the allocated buffer size) instead of
“size” (the logical buffer size) when updating the async_free_space
during the free operation. These are the same except for this
corner case of asynchronous transactions with payloads < 8 bytes.

Affected configurations

Vulners

NVD

Node

linuxlinux_kernelRange4.14–4.14.261

linuxlinux_kernelRange4.15.0–4.19.224

linuxlinux_kernelRange4.20.0–5.4.170

linuxlinux_kernelRange5.5.0–5.10.90

linuxlinux_kernelRange5.11.0–5.15.13

linuxlinux_kernelRange5.16.0≥

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

Vendor	Product	Version	CPE
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::
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": [
      "drivers/android/binder_alloc.c"
    ],
    "versions": [
      {
        "version": "74310e06be4d",
        "lessThan": "2d2df539d052",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "74310e06be4d",
        "lessThan": "7c7064402609",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "74310e06be4d",
        "lessThan": "103b16a8c51f",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "74310e06be4d",
        "lessThan": "1cb8444f3114",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "74310e06be4d",
        "lessThan": "17691bada6b2",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "74310e06be4d",
        "lessThan": "cfd0d84ba28c",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/android/binder_alloc.c"
    ],
    "versions": [
      {
        "version": "4.14",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "4.14",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.14.261",
        "lessThanOrEqual": "4.14.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.224",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.170",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.90",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.13",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.16",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]