CVE-2021-47649

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2021-47649
In the Linux kernel, the following vulnerability has been resolved: udmabuf: validate ubuf->pagecount Syzbot has reported GPF in sg_alloc_append_table_from_pages(). The problem was in ubuf->pages == ZERO_PTR. ubuf->pagecount is calculated from arguments passed from user-space. If user creates udmabuf with list.size == 0 then ubuf->pagecount will be also equal to zero; it causes kmalloc_array() to return ZERO_PTR. Fix it by validating ubuf->pagecount before passing it to kmalloc_array().

5.5 /10

CVSS v3 : MEDIUM

V3 Legend

Vector :

Exploitability : 1.8 / Impact : 3.6

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/2b6dd600dd72573c23ea180b5b0b2f1813405882 Patch
https://git.kernel.org/stable/c/5d50f851dd307c07ca5591297093f19967c834a9 Patch
https://git.kernel.org/stable/c/811b667cefbea9cb7511a874b169d6a92907137e Patch
https://git.kernel.org/stable/c/9e9b4a269f84d3230f2af84ff42322db676440d9 Patch
https://git.kernel.org/stable/c/a3728d32fc61eb0fe283cb8ff60b2c8f751e2202 Patch
https://git.kernel.org/stable/c/b267a8118c2b171bf7d67b90ed64154eeab9fae0 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:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
History

14 Oct 2025, 19:08

Type Values Removed Values Added
First Time Linux
Linux linux Kernel
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 5.5
CWE NVD-CWE-noinfo
Summary
  • (es) En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: udmabuf: validar ubuf->pagecount Syzbot ha informado de un GPF en sg_alloc_append_table_from_pages(). El problema estaba en ubuf->pages == ZERO_PTR. ubuf->pagecount se calcula a partir de los argumentos pasados desde el espacio de usuario. Si el usuario crea udmabuf con list.size == 0, entonces ubuf->pagecount también será igual a cero; esto hace que kmalloc_array() devuelva ZERO_PTR. Arréglelo validando ubuf->pagecount antes de pasarlo a kmalloc_array().
References () https://git.kernel.org/stable/c/2b6dd600dd72573c23ea180b5b0b2f1813405882 - () https://git.kernel.org/stable/c/2b6dd600dd72573c23ea180b5b0b2f1813405882 - Patch
References () https://git.kernel.org/stable/c/5d50f851dd307c07ca5591297093f19967c834a9 - () https://git.kernel.org/stable/c/5d50f851dd307c07ca5591297093f19967c834a9 - Patch
References () https://git.kernel.org/stable/c/811b667cefbea9cb7511a874b169d6a92907137e - () https://git.kernel.org/stable/c/811b667cefbea9cb7511a874b169d6a92907137e - Patch
References () https://git.kernel.org/stable/c/9e9b4a269f84d3230f2af84ff42322db676440d9 - () https://git.kernel.org/stable/c/9e9b4a269f84d3230f2af84ff42322db676440d9 - Patch
References () https://git.kernel.org/stable/c/a3728d32fc61eb0fe283cb8ff60b2c8f751e2202 - () https://git.kernel.org/stable/c/a3728d32fc61eb0fe283cb8ff60b2c8f751e2202 - Patch
References () https://git.kernel.org/stable/c/b267a8118c2b171bf7d67b90ed64154eeab9fae0 - () https://git.kernel.org/stable/c/b267a8118c2b171bf7d67b90ed64154eeab9fae0 - Patch
CPE cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

26 Feb 2025, 06:37

Type Values Removed Values Added
New CVE
Information

Published : 2025-02-26 06:37

Updated : 2025-10-14 19:08

NVD link : CVE-2021-47649

Mitre link : CVE-2021-47649

CVE.ORG link : CVE-2021-47649

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
NVD-CWE-noinfo