CVE-2021-47434

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinuxb92cc66c047ff7cf587b318fe377061a353c120f < 22bcb65ea41072ab5d03c0c6290e04e0df6d09a0affected
LinuxLinuxb92cc66c047ff7cf587b318fe377061a353c120f < 62c182b5e763e5f4062e72678e72ce3e02dd4d1baffected
LinuxLinuxb92cc66c047ff7cf587b318fe377061a353c120f < 01c2dcb67e71c351006dd17cbba86c26b7f61eafaffected
LinuxLinuxb92cc66c047ff7cf587b318fe377061a353c120f < dec944bb7079b37968cf69c8a438f91f15c4cc61affected
LinuxLinuxb92cc66c047ff7cf587b318fe377061a353c120f < e54abefe703ab7c4e5983e889babd1447738ca42affected
LinuxLinuxb92cc66c047ff7cf587b318fe377061a353c120f < ff0e50d3564f33b7f4b35cadeabd951d66cfc570affected
LinuxLinuxbc47204b268516ae4085ebdc81a34ddda71b77c4affected
LinuxLinux88bd928daafb5912c269af628b1e5347620c9a62affected
LinuxLinux2818247b6565b7adfbcd53b74509448a8e1fad84affected
LinuxLinuxef6273930e170a4f70a2c7f57a214813c5cf30bbaffected
LinuxLinuxf83994f3e2438b982fb9821d948199b3327638d8affected
LinuxLinux3.0.49 < 3.1affected
LinuxLinux3.2.32 < 3.3affected
LinuxLinux3.4.13 < 3.5affected
LinuxLinux3.5.6 < 3.6affected
LinuxLinux3.6.1 < 3.7affected
LinuxLinux3.7affected
LinuxLinux0 < 3.7unaffected
LinuxLinux4.14.252 <= 4.14.*unaffected
LinuxLinux4.19.213 <= 4.19.*unaffected
LinuxLinux5.4.155 <= 5.4.*unaffected
LinuxLinux5.10.75 <= 5.10.*unaffected
LinuxLinux5.14.14 <= 5.14.*unaffected
LinuxLinux5.15 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

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

CVE Program Container

Additional References

References