CVE-2021-47434
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).
Does this matter?
Lower severity and a low EPSS score (0.24%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.24% probability · 15th percentile
- CISA KEV
- Not listed
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/01c2dcb67e71c351006dd17cbba86c26b7f61eafPatch
- https://git.kernel.org/stable/c/22bcb65ea41072ab5d03c0c6290e04e0df6d09a0Patch
- https://git.kernel.org/stable/c/62c182b5e763e5f4062e72678e72ce3e02dd4d1bPatch
- https://git.kernel.org/stable/c/dec944bb7079b37968cf69c8a438f91f15c4cc61Patch
- https://git.kernel.org/stable/c/e54abefe703ab7c4e5983e889babd1447738ca42Patch
- https://git.kernel.org/stable/c/ff0e50d3564f33b7f4b35cadeabd951d66cfc570Patch
- https://git.kernel.org/stable/c/01c2dcb67e71c351006dd17cbba86c26b7f61eafPatch
- https://git.kernel.org/stable/c/22bcb65ea41072ab5d03c0c6290e04e0df6d09a0Patch
- https://git.kernel.org/stable/c/62c182b5e763e5f4062e72678e72ce3e02dd4d1bPatch
- https://git.kernel.org/stable/c/dec944bb7079b37968cf69c8a438f91f15c4cc61Patch
- https://git.kernel.org/stable/c/e54abefe703ab7c4e5983e889babd1447738ca42Patch
- https://git.kernel.org/stable/c/ff0e50d3564f33b7f4b35cadeabd951d66cfc570Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.