media: exynos4-is: Prevent NULL pointer dereference in __isp_video_try_fmt()

[ Upstream commit 7c1b9a5aeed91bef98988ac0fcf38c8c1f4f9a3a ]

This patch fixes potential NULL pointer dereference as indicated
by the following static checker warning:

drivers/media/platform/exynos4-is/fimc-isp-video.c:408 isp_video_try_fmt_mplane()
error: NULL dereference inside function '__isp_video_try_fmt(isp, &f->fmt.pix_mp, (0))()'.

Fixes: 34947b8aebe3: ("[media] exynos4-is: Add the FIMC-IS ISP capture DMA driver")

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/media/platform/exynos4-is/fimc-isp-video.c b/drivers/media/platform/exynos4-is/fimc-isp-video.c
index 6e66484..667d372 100644 (file)
--- a/drivers/media/platform/exynos4-is/fimc-isp-video.c
+++ b/drivers/media/platform/exynos4-is/fimc-isp-video.c
@@ -391,12 +391,17 @@ static void __isp_video_try_fmt(struct fimc_isp *isp,
                                struct v4l2_pix_format_mplane *pixm,
                                const struct fimc_fmt **fmt)
 {
-       *fmt = fimc_isp_find_format(&pixm->pixelformat, NULL, 2);
+       const struct fimc_fmt *__fmt;
+
+       __fmt = fimc_isp_find_format(&pixm->pixelformat, NULL, 2);
+
+       if (fmt)
+               *fmt = __fmt;
 
        pixm->colorspace = V4L2_COLORSPACE_SRGB;
        pixm->field = V4L2_FIELD_NONE;
-       pixm->num_planes = (*fmt)->memplanes;
-       pixm->pixelformat = (*fmt)->fourcc;
+       pixm->num_planes = __fmt->memplanes;
+       pixm->pixelformat = __fmt->fourcc;
        /*
         * TODO: double check with the docmentation these width/height
         * constraints are correct.