CVE-2021-47434
XHCI Command Ring Pointer Corruption Write Countermeasures
Description
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.
INFO
Published Date :
May 22, 2024, 7:15 a.m.
Last Modified :
Nov. 21, 2024, 6:36 a.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
Exploitability Score :
References to Advisories, Solutions, and Tools
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CVE-2021-47434.
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The following list is the news that have been mention
CVE-2021-47434 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2021-47434 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Nov. 21, 2024
Action Type Old Value New Value Added Reference https://git.kernel.org/stable/c/01c2dcb67e71c351006dd17cbba86c26b7f61eaf Added Reference https://git.kernel.org/stable/c/22bcb65ea41072ab5d03c0c6290e04e0df6d09a0 Added Reference https://git.kernel.org/stable/c/62c182b5e763e5f4062e72678e72ce3e02dd4d1b Added Reference https://git.kernel.org/stable/c/dec944bb7079b37968cf69c8a438f91f15c4cc61 Added Reference https://git.kernel.org/stable/c/e54abefe703ab7c4e5983e889babd1447738ca42 Added Reference https://git.kernel.org/stable/c/ff0e50d3564f33b7f4b35cadeabd951d66cfc570 -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 28, 2024
Action Type Old Value New Value -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
May. 22, 2024
Action Type Old Value New Value Added Description 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. Added Reference kernel.org https://git.kernel.org/stable/c/22bcb65ea41072ab5d03c0c6290e04e0df6d09a0 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/62c182b5e763e5f4062e72678e72ce3e02dd4d1b [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/01c2dcb67e71c351006dd17cbba86c26b7f61eaf [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/dec944bb7079b37968cf69c8a438f91f15c4cc61 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/e54abefe703ab7c4e5983e889babd1447738ca42 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/ff0e50d3564f33b7f4b35cadeabd951d66cfc570 [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-47434 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2021-47434
weaknesses.