CVE-2022-49766

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

netlink: Bounds-check struct nlmsgerr creation

In preparation for FORTIFY_SOURCE doing bounds-check on memcpy(), switch from __nlmsg_put to nlmsg_put(), and explain the bounds check for dealing with the memcpy() across a composite flexible array struct. Avoids this future run-time warning:

memcpy: detected field-spanning write (size 32) of single field "&errmsg->msg" at net/netlink/af_netlink.c:2447 (size 16)

This patch introduces bounds-checking when creating struct nlmsgerr messages by replacing __nlmsg_put() and memcpy() with nlmsg_put() and unsafe_memcpy(). This prevents potential overreads.

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.