PT-2024-11065 · Linux · Linux Kernel

Ignat Korchagin · Published 2021-04-27 · Updated 2024-04-10 · CVE-2021-46947

Positive Technologies (AI Summary)

CVSS v3.1

5.5

Medium

Base vector

AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Name of the Vulnerable Software and Affected Versions Linux kernel version 5.10.20-cloudflare-2021.3.1

Description The issue arises from the efx->xdp tx queue count being initially initialized to num possible cpus() and later used to allocate and traverse efx->xdp tx queues lookup array. However, not all array slots may be initialized with real queues during probing, resulting in a NULL pointer dereference when running commands like ethtool -S <iface>. This can lead to a kernel crash.

Recommendations To resolve this issue, adjust efx->xdp tx queue count after probing to reflect the true value of initialized slots in efx->xdp tx queues. This adjustment ensures that the kernel accurately accounts for the number of queues available, preventing NULL pointer dereferences and subsequent crashes.

Fix

NULL Pointer Dereference

Weakness Enumeration

CWE-476

Related Identifiers

BDU:2025-02870

CVE-2021-46947

Affected Products

Linux Kernel

References · 15

• https://git.kernel.org/stable/c/99ba0ea616aabdc8e26259fd722503e012199a76 · Patch
• https://git.kernel.org/stable/c/ebeac958b690123a0b40aa61f688f2f170035fad · Patch
• https://nvd.nist.gov/vuln/detail/CVE-2021-46947 · Security Note
• https://osv.dev/vulnerability/UBUNTU-CVE-2021-46947 · Vendor Advisory
• https://security-tracker.debian.org/tracker/CVE-2021-46947 · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2021-46947 · Vendor Advisory
• https://bdu.fstec.ru/vul/2025-02870 · Security Note
• https://cve.org/CVERecord?id=CVE-2021-46947 · Security Note
• https://ubuntu.com/security/CVE-2021-46947 · Vendor Advisory
• https://kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.3 · Note
• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-46947 · Note
• https://lore.kernel.org/linux-cve-announce/[e-mail]/T/#u · Note
• https://lore.kernel.org/linux-cve-announce/[e-mail] · Note
• https://git.kernel.org/linus/99ba0ea616aabdc8e26259fd722503e012199a76 · Note
• https://twitter.com/CVEnew/status/1762551319854768518 · Twitter Post