CVE-2021-47434

xhci: Fix command ring pointer corruption while aborting a command

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.

N/A
CVSS
Severity:
EPSS 0.13%
Affected: Linux Linux
Affected: Linux Linux
Published at:
Updated at:

References

Frequently Asked Questions

What is the severity of CVE-2021-47434?
CVE-2021-47434 has not yet been assigned a CVSS score.
How to fix CVE-2021-47434?
To fix CVE-2021-47434, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-47434 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-47434 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-47434?
CVE-2021-47434 affects Linux Linux, Linux Linux.
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