CVE-2023-52488

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> serial: sc16is7xx: convert from _raw_ to _noinc_ regmap functions for FIFO<br /> <br /> The SC16IS7XX IC supports a burst mode to access the FIFOs where the<br /> initial register address is sent ($00), followed by all the FIFO data<br /> without having to resend the register address each time. In this mode, the<br /> IC doesn&amp;#39;t increment the register address for each R/W byte.<br /> <br /> The regmap_raw_read() and regmap_raw_write() are functions which can<br /> perform IO over multiple registers. They are currently used to read/write<br /> from/to the FIFO, and although they operate correctly in this burst mode on<br /> the SPI bus, they would corrupt the regmap cache if it was not disabled<br /> manually. The reason is that when the R/W size is more than 1 byte, these<br /> functions assume that the register address is incremented and handle the<br /> cache accordingly.<br /> <br /> Convert FIFO R/W functions to use the regmap _noinc_ versions in order to<br /> remove the manual cache control which was a workaround when using the<br /> _raw_ versions. FIFO registers are properly declared as volatile so<br /> cache will not be used/updated for FIFO accesses.