CVE-2024-47749

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

RDMA/cxgb4: Added NULL check for lookup_atid

The lookup_atid() function can return NULL if the ATID is
invalid or does not exist in the identifier table, which
could lead to dereferencing a null pointer without a
check in the `act_establish()` and `act_open_rpl()` functions.
Add a NULL check to prevent null pointer dereferencing.

Found by Linux Verification Center (linuxtesting.org) with SVACE.