CVE-2021-46941

Summary

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/

Affected Software

VendorProductVersion RangeStatus
LinuxLinux41ce1456e1dbbc7355d0fcc10cf7c337c13def24 < fce7bbcd07d59ac30dba8ce225316b3b4c1c7b50affected
LinuxLinux41ce1456e1dbbc7355d0fcc10cf7c337c13def24 < 800f58217626c8b147aa40660e572ed8a0d56e3baffected
LinuxLinux41ce1456e1dbbc7355d0fcc10cf7c337c13def24 < 1c10fd60c8595ea7ff7e29d3cf1fa88069941da3affected
LinuxLinux41ce1456e1dbbc7355d0fcc10cf7c337c13def24 < f88359e1588b85cf0e8209ab7d6620085f3441d9affected
LinuxLinux4.12affected
LinuxLinux0 < 4.12unaffected
LinuxLinux5.10.36 <= 5.10.*unaffected
LinuxLinux5.11.20 <= 5.11.*unaffected
LinuxLinux5.12.3 <= 5.12.*unaffected
LinuxLinux5.13 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References