lkml.org 
[lkml]   [2019]   [Mar]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
SubjectRe: [PATCH] media: rga: fix NULL pointer dereferences
Date
On 09/03/2019 06:35, Kangjie Lu wrote:
> In case __get_free_pages fails, return -ENOMEM to avoid NULL
> pointer dereferences.
>
> Signed-off-by: Kangjie Lu <kjlu@umn.edu>
> ---
> drivers/media/platform/rockchip/rga/rga.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/media/platform/rockchip/rga/rga.c b/drivers/media/platform/rockchip/rga/rga.c
> index 5c653287185f..d42b214977a9 100644
> --- a/drivers/media/platform/rockchip/rga/rga.c
> +++ b/drivers/media/platform/rockchip/rga/rga.c
> @@ -892,8 +892,13 @@ 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)
> + return -ENOMEM;
> +
> rga->dst_mmu_pages =
> (unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);
> + if (!rga->dst_mmu_pages)
> + return -ENOMEM;

I believe you need to perform clean up when probe fails, not just return
early, e.g. with a 'goto' to the existing clean up code at the end of
the function.

Also from what I can tell there is already a potential memory leak if
video_register_device() fails. You probably want something more like the
(completely untested) change below.

Steve

----8<----
diff --git a/drivers/media/platform/rockchip/rga/rga.c
b/drivers/media/platform/rockchip/rga/rga.c
index 5c653287185f..8df1945594ab 100644
--- a/drivers/media/platform/rockchip/rga/rga.c
+++ b/drivers/media/platform/rockchip/rga/rga.c
@@ -895,6 +895,11 @@ static int rga_probe(struct platform_device *pdev)
rga->dst_mmu_pages =
(unsigned int *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, 3);

+ if (!rga->src_mmu_pages || !rga->dst_mmu_pages) {
+ ret = -ENOMEM;
+ goto free_mem;
+ }
+
def_frame.stride = (def_frame.width * def_frame.fmt->depth) >> 3;
def_frame.size = def_frame.stride * def_frame.height;

@@ -911,6 +916,9 @@ static int rga_probe(struct platform_device *pdev)

rel_vdev:
video_device_release(vfd);
+free_mem:
+ free_pages((unsigned long)rga->src_mmu_pages, 3);
+ free_pages((unsigned long)rga->dst_mmu_pages, 3);
unreg_video_dev:
video_unregister_device(rga->vfd);
unreg_v4l2_dev:
\
 
 \ /
  Last update: 2019-03-11 14:16    [W:0.098 / U:14.252 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site