CVE-2021-47479

  1. OpenCVE
  2. Vulnerabilities (CVE)
  3. CVE-2021-47479
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

7.0 /10

CVSS v3 : HIGH

V3 Legend

Vector :

Exploitability : 1.0 / Impact : 5.9

Attack Vector LOCAL

Attack Complexity HIGH

Privileges Required LOW

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact HIGH

Scope UNCHANGED

References
Link Resource
https://git.kernel.org/stable/c/a65c9afe9f2f55b7a7fb4a25ab654cd4139683a4 Patch
https://git.kernel.org/stable/c/befd23bd3b17f1a3f9c943a8580b47444c7c63ed Patch
https://git.kernel.org/stable/c/c052cc1a069c3e575619cf64ec427eb41176ca70 Patch
https://git.kernel.org/stable/c/c430094541a80575259a94ff879063ef01473506 Patch
https://git.kernel.org/stable/c/a65c9afe9f2f55b7a7fb4a25ab654cd4139683a4 Patch
https://git.kernel.org/stable/c/befd23bd3b17f1a3f9c943a8580b47444c7c63ed Patch
https://git.kernel.org/stable/c/c052cc1a069c3e575619cf64ec427eb41176ca70 Patch
https://git.kernel.org/stable/c/c430094541a80575259a94ff879063ef01473506 Patch
Configurations

Configuration 1 (hide)

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.3:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.3:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.3:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.3:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.3:rc7:*:*:*:*:*:*
History

24 Sep 2025, 19:04

Type Values Removed Values Added
CVSS v2 : unknown
v3 : unknown 		v2 : unknown
v3 : 7.0
References () https://git.kernel.org/stable/c/a65c9afe9f2f55b7a7fb4a25ab654cd4139683a4 - () https://git.kernel.org/stable/c/a65c9afe9f2f55b7a7fb4a25ab654cd4139683a4 - Patch
References () https://git.kernel.org/stable/c/befd23bd3b17f1a3f9c943a8580b47444c7c63ed - () https://git.kernel.org/stable/c/befd23bd3b17f1a3f9c943a8580b47444c7c63ed - Patch
References () https://git.kernel.org/stable/c/c052cc1a069c3e575619cf64ec427eb41176ca70 - () https://git.kernel.org/stable/c/c052cc1a069c3e575619cf64ec427eb41176ca70 - Patch
References () https://git.kernel.org/stable/c/c430094541a80575259a94ff879063ef01473506 - () https://git.kernel.org/stable/c/c430094541a80575259a94ff879063ef01473506 - Patch
First Time Linux linux Kernel
Linux
CWE CWE-416
CPE cpe:2.3:o:linux:linux_kernel:3.3:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.3:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.3:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.3:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:3.3:-:*:*:*:*:*:*

21 Nov 2024, 06:36

Type Values Removed Values Added
Summary
  • (es) En el kernel de Linux, se resolvió la siguiente vulnerabilidad: staging: rtl8712: corrige el use-after-free en rtl8712_dl_fw Syzbot informó el use-after-free en rtl8712_dl_fw(). El problema estaba en la condición de ejecución entre la devolución de llamada r871xu_dev_remove() ->ndo_open(). Es fácil ver en el registro de fallos que el controlador accede al firmware lanzado en la devolución de llamada ->ndo_open(). Puede suceder, ya que el controlador estaba lanzando el firmware _antes_ de cancelar el registro de netdev. Solucionarlo moviendo unregister_netdev() antes de limpiar los recursos. Traza de llamada: ... RTL871X_OPEN_FW : 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 Liberado por tarea 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
References () https://git.kernel.org/stable/c/a65c9afe9f2f55b7a7fb4a25ab654cd4139683a4 - () https://git.kernel.org/stable/c/a65c9afe9f2f55b7a7fb4a25ab654cd4139683a4 -
References () https://git.kernel.org/stable/c/befd23bd3b17f1a3f9c943a8580b47444c7c63ed - () https://git.kernel.org/stable/c/befd23bd3b17f1a3f9c943a8580b47444c7c63ed -
References () https://git.kernel.org/stable/c/c052cc1a069c3e575619cf64ec427eb41176ca70 - () https://git.kernel.org/stable/c/c052cc1a069c3e575619cf64ec427eb41176ca70 -
References () https://git.kernel.org/stable/c/c430094541a80575259a94ff879063ef01473506 - () https://git.kernel.org/stable/c/c430094541a80575259a94ff879063ef01473506 -

22 May 2024, 09:15

Type Values Removed Values Added
New CVE
Information

Published : 2024-05-22 09:15

Updated : 2025-09-24 19:04

NVD link : CVE-2021-47479

Mitre link : CVE-2021-47479

CVE.ORG link : CVE-2021-47479

JSON object : View

Products Affected

linux

  • linux_kernel
CWE
CWE-416

Use After Free