CVE-2023-52488 serial: sc16is7xx: convert from _raw_ to _noinc_ regmap functions for FIFO
A bug in the SC16IS7XX serial driver caused regmap cache corruption when using raw functions for FIFO access, fixed by switching to noinc functions.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-52488?
CVE-2023-52488 is a medium-severity vulnerability in Linux kernel, published on 29 Feb 2024. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
serial: sc16is7xx: convert from _raw_ to _noinc_ regmap functions for FIFO
The SC16IS7XX IC supports a burst mode to access the FIFOs where the initial register address is sent ($00), followed by all the FIFO data without having to resend the register address each time. In this mode, the IC doesn't increment the register address for each R/W byte.
The regmap_raw_read() and regmap_raw_write() are functions which can perform IO over multiple registers. They are currently used to read/write from/to the FIFO, and although they operate correctly in this burst mode on the SPI bus, they would corrupt the regmap cache if it was not disabled manually. The reason is that when the R/W size is more than 1 byte, these functions assume that the register address is incremented and handle the cache accordingly.
Convert FIFO R/W functions to use the regmap _noinc_ versions in order to remove the manual cache control which was a workaround when using the _raw_ versions. FIFO registers are properly declared as volatile so cache will not be used/updated for FIFO accesses.
Which versions are affected by CVE-2023-52488?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2023-52488?
Apply the vendor's patch.
Is CVE-2023-52488 being exploited?
There is no known exploitation of CVE-2023-52488 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-56816, BELL-CVE-2023-52488, DEBIAN-CVE-2023-52488, GHSA-857w-h46r-9g9g, UBUNTU-CVE-2023-52488.