CVE-2021-47649

MEDIUM EPSS 13.3%
Published Feb 26, 20251y ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Feb 26, 2025 1y ago
Last Modified Jun 17, 2026 1w ago

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().

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
13.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 5

VendorProductVersionRange
linuxlinux_kernel*≥4.20  –  <5.4.189
linuxlinux_kernel*≥5.5  –  <5.10.110
linuxlinux_kernel*≥5.11  –  <5.15.33
linuxlinux_kernel*≥5.16  –  <5.16.19
linuxlinux_kernel*≥5.17  –  <5.17.2

References 6

  • git.kernel.org https://git.kernel.org/stable/c/2b6dd600dd72573c23ea180b5b0b2f1813405882
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5d50f851dd307c07ca5591297093f19967c834a9
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/811b667cefbea9cb7511a874b169d6a92907137e
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9e9b4a269f84d3230f2af84ff42322db676440d9
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a3728d32fc61eb0fe283cb8ff60b2c8f751e2202
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b267a8118c2b171bf7d67b90ed64154eeab9fae0
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/2b6dd600dd72573c23ea180b5b0b2f1813405882
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/5d50f851dd307c07ca5591297093f19967c834a9
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/811b667cefbea9cb7511a874b169d6a92907137e
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9e9b4a269f84d3230f2af84ff42322db676440d9
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a3728d32fc61eb0fe283cb8ff60b2c8f751e2202
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b267a8118c2b171bf7d67b90ed64154eeab9fae0
    Patch