CVE-2021-47649

MediumCVSS 5.5/10Last modified Jun 17, 2026

Description

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().

Metrics

CVSS 3.1 5.5/10CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected software

No affected versions have been published.

Timeline

Published
Feb 26, 2025
Last modified
Jun 17, 2026
NVD status
Analyzed

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CVE-2021-47649: Medium severity, CVSS 5.5 | Vulnix