dmaengine: idxd: Fix potential null dereference on pointer status

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Fix potential null dereference on pointer status There are calls to idxd_cmd_exec that pass a null status pointer however a recent commit has added an assignment to *status that can end up with a null pointer dereference. The function expects a null status pointer sometimes as there is a later assignment to *status where status is first null checked. Fix the issue by null checking status before making the assignment. Addresses-Coverity: ("Explicit null dereferenced")

References

• https://git.kernel.org/stable/c/5756f757c72501ef1a16f5f63f940623044180e9
• https://git.kernel.org/stable/c/2280b4cc29d8cdd2be3d1b2d1ea4f958e2131c97
• https://git.kernel.org/stable/c/7bc402f843e7817a4a808e7b9ab0bcd7ffd55bfa
• https://git.kernel.org/stable/c/28ac8e03c43dfc6a703aa420d18222540b801120