In the Linux kernel, the following vulnerability has been resolved:
arm64: process: Fix context switching MTE store-only tag check
SCTLR_EL1.TCSO0 is set when user opt-in for MTE store-only tag check
mode. However, it is not part of SCTLR_USER_MASK which imply that on
context switch we never clear SCTLR_EL1.TCSO0, so we are leaking that
setting into another task.
Fix that by including SCTLR_EL1_TCSO0_MASK into SCTLR_USER_MASK
