CVE-2021-47461

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  2. Vulnerabilities (CVE)
  3. CVE-2021-47461

4.7 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.0 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

I

n the Linux kernel, the following vulnerability has been resolved: userfaultfd: fix a race between writeprotect and exit_mmap() A race is possible when a process exits, its VMAs are removed by exit_mmap() and at the same time userfaultfd_writeprotect() is called. The race was detected by KASAN on a development kernel, but it appears to be possible on vanilla kernels as well. Use mmget_not_zero() to prevent the race as done in other userfaultfd operations.

References
Link Resource
https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a Patch
https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525 Patch
https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca Patch
https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a Patch
https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525 Patch
https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc6:*:*:*:*:*:*
History

24 Sep 2025, 12:38

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 4.7
CPE cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
References () https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a - () https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a - Patch
References () https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525 - () https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525 - Patch
References () https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca - () https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca - Patch
First Time Linux
Linux linux Kernel
CWE CWE-362

21 Nov 2024, 06:36

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a - () https://git.kernel.org/stable/c/149958ecd0627a9f1e9c678c25c665400054cd6a -
References () https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525 - () https://git.kernel.org/stable/c/3cda4bfffd4f755645577aaa9e96a606657b4525 -
References () https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca - () https://git.kernel.org/stable/c/cb185d5f1ebf900f4ae3bf84cee212e6dd035aca -
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: userfaultfd: corrige una ejecución entre writeprotect y exit_mmap() Una ejecución es posible cuando un proceso sale, sus VMA son eliminados por exit_mmap() y al mismo tiempo se llama a userfaultfd_writeprotect() . KASAN detectó la ejecución en un núcleo de desarrollo, pero parece ser posible también en núcleos de vainilla. Utilice mmget_not_zero() para evitar la ejecución como se hace en otras operaciones de userfaultfd.

22 May 2024, 07:15

Type Values Removed Values Added
New CVE
Information

Published : 2024-05-22 07:15

Updated : 2025-09-24 12:38

NVD link : CVE-2021-47461

Mitre link : CVE-2021-47461

CVE.ORG link : CVE-2021-47461

JSON object : View

Products Affected

linux

CWE
CWE-362

Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')