Fd is a user-accessible value, referring it multiple times
leads to TOCTOU issues. Dma_buf can be freed after the 1st
use of fd and userspace can create another dma_buf but with
same fd. In such scenario, during 2nd use of fd, we may get
a different dma_buf with different length. To avoid this, we
can use same dma_buf instead of retrieving it twice using same
fd. In this change FD is accessed only once in syscall.
CRs-Fixed: 3159446
Change-Id: I00eb6dd3d798165f5c6c0bd59feabe80a68592b1
Signed-off-by: Yash Upadhyay <quic_yupadhya@quicinc.com>
336163ddec