In the Linux kernel, the following vulnerability has been resolved: nvmet: fix NULL pointer dereference in nvmet_execute_identify_nslist()

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

nvmet: fix NULL pointer dereference in nvmet_execute_identify_nslist()

When a host issues an Identify command with CNS 07h (Active Namespace ID
List for a specific I/O Command Set), nvmet_execute_identify_nslist() is
called with match_css set. The command-set filter dereferences req->ns,
but this handler never calls nvmet_req_find_ns(), so req->ns is always
NULL (nvmet_req_init() resets it to NULL). As soon as an enabled
namespace with an NSID greater than the requested value exists,
req->ns->csi dereferences a NULL pointer and oopses.

Besides the crash, the comparison is logically wrong: to filter the list
by command set it must test the command set of the namespace being
iterated, not a single fixed value. Use the loop variable ns->csi.