[PATCH v2] media: rga: fix NULL pointer dereferences and a memory leak

[Kangjie Lu]

In case __get_free_pages fails, the fix releases resources and
return -ENOMEM to avoid NULL pointer dereferences.

Also, the fix frees pages when video_register_device fails to
avoid a memory leak.

Signed-off-by: Kangjie Lu <k...@umn.edu>
---
 drivers/media/platform/rockchip/rga/rga.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/rockchip/rga/rga.c 
b/drivers/media/platform/rockchip/rga/rga.c
index 5c653287185f..307b7ab0ab64 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -892,8 +892,17 @@ static int rga_probe(struct platform_device *pdev)
 
        rga->src_mmu_pages =
                (unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+       if (!rga->src_mmu_pages) {
+               ret = -ENOMEM;
+               goto rel_vdev;
+       }
+
        rga->dst_mmu_pages =
                (unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
+       if (!rga->dst_mmu_pages) {
+               ret = -ENOMEM;
+               goto free_dst_pages;
+       }
 
        def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
        def_frame.size = def_frame.stride * def_frame.height;
@@ -901,7 +910,7 @@ static int rga_probe(struct platform_device *pdev)
        ret = video_register_device(vfd, VFL_TYPE_GRABBER, -1);
        if (ret) {
                v4l2_err(&rga->v4l2_dev, "Failed to register video device\n");
-               goto rel_vdev;
+               goto free_pages;
        }
 
        v4l2_info(&rga->v4l2_dev, "Registered %s as /dev/%s\n",
@@ -909,6 +918,10 @@ static int rga_probe(struct platform_device *pdev)
 
        return 0;
 
+free_pages:
+       free_pages((unsigned long)rga->src_mmu_pages, 3);
+free_dst_pages:
+       free_pages((unsigned long)rga->dst_mmu_pages, 3);
 rel_vdev:
        video_device_release(vfd);
 unreg_video_dev:
-- 
2.17.1