CVE-2021-47479

What it is

In the Linux kernel, the following vulnerability has been resolved: staging: rtl8712: fix use-after-free in rtl8712_dl_fw Syzbot reported use-after-free in rtl8712_dl_fw(). The problem was in race condition between r871xu_dev_remove() ->ndo_open() callback. It's easy to see from crash log, that driver accesses released firmware in ->ndo_open() callback. It may happen, since driver was releasing firmware _before_ unregistering netdev. Fix it by moving unregister_netdev() before cleaning up resources. Call Trace: ... rtl871x_open_fw drivers/staging/rtl8712/hal_init.c:83 [inline] rtl8712_dl_fw+0xd95/0xe10 drivers/staging/rtl8712/hal_init.c:170 rtl8712_hal_init drivers/staging/rtl8712/hal_init.c:330 [inline] rtl871x_hal_init+0xae/0x180 drivers/staging/rtl8712/hal_init.c:394 netdev_open+0xe6/0x6c0 drivers/staging/rtl8712/os_intfs.c:380 __dev_open+0x2bc/0x4d0 net/core/dev.c:1484 Freed by task 1306: ... release_firmware+0x1b/0x30 drivers/base/firmware_loader/main.c:1053 r871xu_dev_remove+0xcc/0x2c0 drivers/staging/rtl8712/usb_intf.c:599 usb_unbind_interface+0x1d8/0x8d0 drivers/usb/core/driver.c:458

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, data tampering, service disruption.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2024-05-22 09:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 04:17 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 7.0 HIGH (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2024-05-22 09:15 UTC

Last modified

2026-06-17 04:17 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-416 · Use after free

Record status

Analyzed

Affected

• Linux Kernel < 3.3
• Linux Kernel < 5.10.79
• Linux Kernel < 5.14.18
• Linux Kernel < 5.15.2
• Linux Kernel 3.3

Attack profile CVSS 3.1 · 7.0

Attack vector

Local

Complexity

High

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2021-47479.md and follow it. Check whether this project is affected by CVE-2021-47479. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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