msm: kgsl: improved bounds checking on user-specified parameters

Verify that the user specified length for a PMEM region is smaller than the
size of the entire region as reported by the kernel APIs.

Change-Id: Ic0dedbad0127bdaed70eafc00238b44f982b093b
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Iliyan Malchev <malchev@google.com>
diff --git a/drivers/gpu/msm/kgsl_sharedmem.h b/drivers/gpu/msm/kgsl_sharedmem.h
index 034ade4..7dc78b2 100644
--- a/drivers/gpu/msm/kgsl_sharedmem.h
+++ b/drivers/gpu/msm/kgsl_sharedmem.h
@@ -117,6 +117,8 @@
 		unsigned int physaddr, unsigned int size)
 {
 	memdesc->sg = kgsl_sg_alloc(1);
+	if (!memdesc->sg)
+		return -ENOMEM;
 
 	kmemleak_not_leak(memdesc->sg);