soundwire: cadence: fix invalid PDI offset

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: soundwire: cadence: fix invalid PDI offset For some reason, we add an offset to the PDI, presumably to skip the PDI0 and PDI1 which are reserved for BPT. This code is however completely wrong and leads to an out-of-bounds access. We were just lucky so far since we used only a couple of PDIs and remained within the PDI array bounds. A Fixes: tag is not provided since there are no known platforms where the out-of-bounds would be accessed, and the initial code had problems as well. A follow-up patch completely removes this useless offset.

References

• https://git.kernel.org/stable/c/002364b2d594a9afc0385c09e00994c510b1d089
• https://git.kernel.org/stable/c/fd4bcb991ebaf0d1813d81d9983cfa99f9ef5328
• https://git.kernel.org/stable/c/902f6d656441a511ac25c6cffce74496db10a078
• https://git.kernel.org/stable/c/2ebcaa0e5db9b6044bb487ae1cf41bc601761567
• https://git.kernel.org/stable/c/7eeef1e935d23db5265233d92395bd5c648a4021
• https://git.kernel.org/stable/c/4e99103f757cdf636c6ee860994a19a346a11785
• https://git.kernel.org/stable/c/8ee1b439b1540ae543149b15a2a61b9dff937d91