In the Linux kernel, the following vulnerability has been resolved: arm64: percpu: Fix LSE...

In the Linux kernel, the following vulnerability has been resolved:

arm64: percpu: Fix LSE operations on {8,16}-bit types

The assembly for _percpu##name##case##sz() and _percpu##name##return_case##sz() doesn't use the 'sfx' macro argument to form the LSE instruction. Without 'sfx', a W register argument will imply a 32-bit memory location, and consequently {8,16}-bit ops will erroneously read and write 32 bits of memory when the LSE instruction is used.

Fix this by appending 'sfx' to 'op_lse' to LSE instruction. It is not necessary (and not valid) to append 'sfx' to 'op_llsc', as 'op_llsc' is a register-register operation which does not access memory (and does not take a size suffix).