[PATCH 4.17 12/46] staging: android: ion: Return an ERR_PTR in ion_map_kernel

[Greg Kroah-Hartman]

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Laura Abbott <labbott@xxxxxxxxxx>

commit 0a2bc00341dcfcc793c0dbf4f8d43adf60458b05 upstream.

The expected return value from ion_map_kernel is an ERR_PTR. The error
path for a vmalloc failure currently just returns NULL, triggering
a warning in ion_buffer_kmap_get. Encode the vmalloc failure as an ERR_PTR.

Reported-by: syzbot+55b1d9f811650de944c6@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Laura Abbott <labbott@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/staging/android/ion/ion_heap.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/staging/android/ion/ion_heap.c
+++ b/drivers/staging/android/ion/ion_heap.c
@@ -29,7 +29,7 @@ void *ion_heap_map_kernel(struct ion_hea
 	struct page **tmp = pages;
 
 	if (!pages)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	if (buffer->flags & ION_FLAG_CACHED)
 		pgprot = PAGE_KERNEL;