Instituto Nacional de ciberseguridad. Sección Incibe
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CVE-2021-47649

Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
26/02/2025
Last modified:
14/10/2025

Description

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

Impact

Vector 3.x
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H CVSS v3.1 Severity and Metrics:

Base Score: 5.50 MEDIUM
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack Vector (AV): Local
Attack Complexity (AC): Low
Privileges Required (PR): Low
User Interaction (UI): None
Scope (S): Unchanged
Confidentiality (C): None
Integrity (I): None
Availability (A): High

Base Score 3.x
5.50
Severity 3.x
MEDIUM

Vulnerable products and versions

CPE From Up to
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 4.20 (including) 5.4.189 (excluding)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 5.5 (including) 5.10.110 (excluding)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 5.11 (including) 5.15.33 (excluding)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 5.16 (including) 5.16.19 (excluding)
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* 5.17 (including) 5.17.2 (excluding)

To consult the complete list of CPE names with products and versions, see this page


References to Advisories, Solutions, and Tools