[media] media: vb2: fix queueing of userptr buffers with null buffer pointer
[media] media: vb2: fix queueing of userptr buffers with null buffer pointer

Heuristic that checks if the memory pointer has been changed lacked a check
if the pointer was actually provided by the userspace, what allowed one to
queue a NULL pointer which was accepted without further checking. This
patch fixes this issue.

Reported-by: Sylwester Nawrocki <1ca386fdc5066df13f7236f0837f22126191d06b@samsung.com>
Signed-off-by: Marek Szyprowski <2a0259761cc3e88db42be5300c1579a67c77e65e@samsung.com>
Signed-off-by: Kyungmin Park <504c23c4986a3760712724894be3105092c27331@samsung.com>
CC: Pawel Osciak <5564a40b3044389cdd055bde6a926496e668fbf8@osciak.com>
Signed-off-by: Mauro Carvalho Chehab <ad86ba2154032c9f55743a190faa2459a9d61d42@redhat.com>

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas