CVE-2024-47408

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

net/smc: check smcd_v2_ext_offset when receiving proposal msg

When receiving proposal msg in server, the field smcd_v2_ext_offset in
proposal msg is from the remote client and can not be fully trusted.
Once the value of smcd_v2_ext_offset exceed the max value, there has
the chance to access wrong address, and crash may happen.

This patch checks the value of smcd_v2_ext_offset before using it.