CVE-2021-47434

In the Linux kernel, the following vulnerability has been resolved: xhci: Fix command ring pointer corruption while aborting a command The command ring pointer is located at [6:63] bits of the command ring control register (CRCR). All the control bits like command stop, abort are located at [0:3] bits. While aborting a command, we read the CRCR and set the abort bit and write to the CRCR. The read will always give command ring pointer as all zeros. So we essentially write only the control bits. Since we split the 64 bit write into two 32 bit writes, there is a possibility of xHC command ring stopped before the upper dword (all zeros) is written. If that happens, xHC updates the upper dword of its internal command ring pointer with all zeros. Next time, when the command ring is restarted, we see xHC memory access failures. Fix this issue by only writing to the lower dword of CRCR where all control bits are located.
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:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*

History

25 Sep 2025, 15:58

Type Values Removed Values Added
CPE cpe:2.3:o:linux:linux_kernel:5.15:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.15:rc3:*:*:*:*:*:*
First Time Linux linux Kernel
Linux
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 5.5
CWE NVD-CWE-noinfo
References () https://git.kernel.org/stable/c/01c2dcb67e71c351006dd17cbba86c26b7f61eaf - () https://git.kernel.org/stable/c/01c2dcb67e71c351006dd17cbba86c26b7f61eaf - Patch
References () https://git.kernel.org/stable/c/22bcb65ea41072ab5d03c0c6290e04e0df6d09a0 - () https://git.kernel.org/stable/c/22bcb65ea41072ab5d03c0c6290e04e0df6d09a0 - Patch
References () https://git.kernel.org/stable/c/62c182b5e763e5f4062e72678e72ce3e02dd4d1b - () https://git.kernel.org/stable/c/62c182b5e763e5f4062e72678e72ce3e02dd4d1b - Patch
References () https://git.kernel.org/stable/c/dec944bb7079b37968cf69c8a438f91f15c4cc61 - () https://git.kernel.org/stable/c/dec944bb7079b37968cf69c8a438f91f15c4cc61 - Patch
References () https://git.kernel.org/stable/c/e54abefe703ab7c4e5983e889babd1447738ca42 - () https://git.kernel.org/stable/c/e54abefe703ab7c4e5983e889babd1447738ca42 - Patch
References () https://git.kernel.org/stable/c/ff0e50d3564f33b7f4b35cadeabd951d66cfc570 - () https://git.kernel.org/stable/c/ff0e50d3564f33b7f4b35cadeabd951d66cfc570 - Patch

21 Nov 2024, 06:36

Type Values Removed Values Added
References () https://git.kernel.org/stable/c/01c2dcb67e71c351006dd17cbba86c26b7f61eaf - () https://git.kernel.org/stable/c/01c2dcb67e71c351006dd17cbba86c26b7f61eaf -
References () https://git.kernel.org/stable/c/22bcb65ea41072ab5d03c0c6290e04e0df6d09a0 - () https://git.kernel.org/stable/c/22bcb65ea41072ab5d03c0c6290e04e0df6d09a0 -
References () https://git.kernel.org/stable/c/62c182b5e763e5f4062e72678e72ce3e02dd4d1b - () https://git.kernel.org/stable/c/62c182b5e763e5f4062e72678e72ce3e02dd4d1b -
References () https://git.kernel.org/stable/c/dec944bb7079b37968cf69c8a438f91f15c4cc61 - () https://git.kernel.org/stable/c/dec944bb7079b37968cf69c8a438f91f15c4cc61 -
References () https://git.kernel.org/stable/c/e54abefe703ab7c4e5983e889babd1447738ca42 - () https://git.kernel.org/stable/c/e54abefe703ab7c4e5983e889babd1447738ca42 -
References () https://git.kernel.org/stable/c/ff0e50d3564f33b7f4b35cadeabd951d66cfc570 - () https://git.kernel.org/stable/c/ff0e50d3564f33b7f4b35cadeabd951d66cfc570 -
Summary
  • (es) En el kernel de Linux, se resolvió la siguiente vulnerabilidad: xhci: corrige la corrupción del puntero del anillo de comando al cancelar un comando. El puntero del anillo de comando está ubicado en los bits [6:63] del registro de control del anillo de comando (CRCR). Todos los bits de control, como el comando de parada y cancelación, se encuentran en bits [0:3]. Mientras abortamos un comando, leemos el CRCR, configuramos el bit de cancelación y escribimos en el CRCR. La lectura siempre dará un puntero de anillo de comando como todo ceros. Básicamente, escribimos sólo los bits de control. Dado que dividimos la escritura de 64 bits en dos escrituras de 32 bits, existe la posibilidad de que el anillo de comando xHC se detenga antes de que se escriba la palabra d superior (todo ceros). Si eso sucede, xHC actualiza la palabra clave superior de su puntero de anillo de comando interno con todo ceros. La próxima vez, cuando se reinicie el anillo de comando, veremos fallas de acceso a la memoria xHC. Solucione este problema escribiendo únicamente en la palabra clave inferior de CRCR donde se encuentran todos los bits de control.

22 May 2024, 07:15

Type Values Removed Values Added
New CVE

Information

Published : 2024-05-22 07:15

Updated : 2025-09-25 15:58


NVD link : CVE-2021-47434

Mitre link : CVE-2021-47434

CVE.ORG link : CVE-2021-47434


JSON object : View

Products Affected

linux

  • linux_kernel