CVE-2021-46941

MEDIUMCVSS 5.5/10EPSS 0.22%

Last modified

CVE-2021-46941 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: core: Do core softreset when switch mode According to the programming guide, to switch mode for DRD controller, the driver needs to do the following. To switch from device to host: 1. Reset controller with GCTL.CoreSoftReset 2. EPSS estimates a 0.22% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: core: Do core softreset when switch mode According to the programming guide, to switch mode for DRD controller, the driver needs to do the following. To switch from device to host: 1. Reset controller with GCTL.CoreSoftReset 2. Set GCTL.PrtCapDir(host mode) 3. Reset the host with USBCMD.HCRESET 4. Then follow up with the initializing host registers sequence To switch from host to device: 1. Reset controller with GCTL.CoreSoftReset 2. Set GCTL.PrtCapDir(device mode) 3. Reset the device with DCTL.CSftRst 4. Then follow up with the initializing registers sequence Currently we're missing step 1) to do GCTL.CoreSoftReset and step 3) of switching from host to device. John Stult reported a lockup issue seen with HiKey960 platform without these steps[1]. Similar issue is observed with Ferry's testing platform[2]. So, apply the required steps along with some fixes to Yu Chen's and John Stultz's version. The main fixes to their versions are the missing wait for clocks synchronization before clearing GCTL.CoreSoftReset and only apply DCTL.CSftRst when switching from host to device. [1] https://lore.kernel.org/linux-usb/20210108015115.27920-1-john.stultz@linaro.org/ [2] https://lore.kernel.org/linux-usb/0ba7a6ba-e6a7-9cd4-0695-64fc927e01f1@gmail.com/

Metrics

CVSS 3.1
5.5/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Probability
0.22%

13.0th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

VendorProductVersions
LinuxLinux Kernel>= 4.12.0, < 5.10.36
LinuxLinux Kernel>= 5.11.0, < 5.11.20
LinuxLinux Kernel>= 5.12.0, < 5.12.3

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-46941?
In the Linux kernel, the following vulnerability has been resolved: usb: dwc3: core: Do core softreset when switch mode According to the programming guide, to switch mode for DRD controller, the driver needs to do the following. To switch from device to host: 1. Reset controller with GCTL.CoreSoftReset 2. Set GCTL.PrtCapDir(host mode) 3. Reset the host with USBCMD.HCRESET 4. Then follow up with the initializing host registers sequence To switch from host to device: 1. Reset controller with GCTL.CoreSoftReset 2. Set GCTL.PrtCapDir(device mode) 3. Reset the device with DCTL.CSftRst 4. Then follow up with the initializing registers sequence Currently we're missing step 1) to do GCTL.CoreSoftReset and step 3) of switching from host to device. John Stult reported a lockup issue seen with HiKey960 platform without these steps[1]. Similar issue is observed with Ferry's testing platform[2]. So, apply the required steps along with some fixes to Yu Chen's and John Stultz's version. The main fixes to their versions are the missing wait for clocks synchronization before clearing GCTL.CoreSoftReset and only apply DCTL.CSftRst when switching from host to device. [1] https://lore.kernel.org/linux-usb/20210108015115.27920-1-john.stultz@linaro.org/ [2] https://lore.kernel.org/linux-usb/0ba7a6ba-e6a7-9cd4-0695-64fc927e01f1@gmail.com/
How severe is CVE-2021-46941?
CVE-2021-46941 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.22% probability of exploitation in the next 30 days.
How do I fix CVE-2021-46941?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST