CVE-2024-58069

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

rtc: pcf85063: fix potential OOB write in PCF85063 NVMEM read

The nvmem interface supports variable buffer sizes, while the regmap interface operates with fixed-size storage. If an nvmem client uses a buffer size less than 4 bytes, regmap_read will write out of bounds as it expects the buffer to point at an unsigned int.

Fix this by using an intermediary unsigned int to hold the value.

The issue is actual only for the latest versions of Red Hat Enterprise Linux (starting from the Red Hat Enterprise Linux 9). The bug could happen only if PCF85063 RTC chip being used. Only privileged user could trigger it (if have access to read some parameters from such device). The security impact is limited, because only few bytes of data corruption could happen (but still potentially could be used for privileges escalation).

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent module rtc-pcf85063 from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.