media: tegra-video: Fix memory leak in __tegra_channel_try_format()

The state object allocated by __v4l2_subdev_state_alloc() must be freed
with __v4l2_subdev_state_free() when it is no longer needed.

In __tegra_channel_try_format(), two error paths return directly after
v4l2_subdev_call() fails, without freeing the allocated 'sd_state'
object. This violates the requirement and causes a memory leak.

Fix this by introducing a cleanup label and using goto statements in the
error paths to ensure that __v4l2_subdev_state_free() is always called
before the function returns.

Fixes: 56f64b82356b7 ("media: tegra-video: Use zero crop settings if subdev has no get_selection")
Fixes: 1ebaeb09830f3 ("media: tegra-video: Add support for external sensor capture")
Cc: stable@vger.kernel.org
Signed-off-by: Zilin Guan <zilin@seu.edu.cn>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>

diff --git a/drivers/staging/media/tegra-video/vi.c b/drivers/staging/media/tegra-video/vi.c
index c9276ff76157fa2d17e05df271c6ebea4b4455ed..14b327afe045e60e6c7381390db8a219c43c88a0 100644 (file)
--- a/drivers/staging/media/tegra-video/vi.c
+++ b/drivers/staging/media/tegra-video/vi.c
@@ -438,7 +438,7 @@ static int __tegra_channel_try_format(struct tegra_vi_channel *chan,
                .target = V4L2_SEL_TGT_CROP_BOUNDS,
        };
        struct v4l2_rect *try_crop;
-       int ret;
+       int ret = 0;
 
        subdev = tegra_channel_get_remote_source_subdev(chan);
        if (!subdev)
@@ -482,8 +482,10 @@ static int __tegra_channel_try_format(struct tegra_vi_channel *chan,
                } else {
                        ret = v4l2_subdev_call(subdev, pad, get_selection,
                                               NULL, &sdsel);
-                       if (ret)
-                               return -EINVAL;
+                       if (ret) {
+                               ret = -EINVAL;
+                               goto out_free;
+                       }
 
                        try_crop->width = sdsel.r.width;
                        try_crop->height = sdsel.r.height;
@@ -495,14 +497,15 @@ static int __tegra_channel_try_format(struct tegra_vi_channel *chan,
 
        ret = v4l2_subdev_call(subdev, pad, set_fmt, sd_state, &fmt);
        if (ret < 0)
-               return ret;
+               goto out_free;
 
        v4l2_fill_pix_format(pix, &fmt.format);
        chan->vi->ops->vi_fmt_align(pix, fmtinfo->bpp);
 
+out_free:
        __v4l2_subdev_state_free(sd_state);
 
-       return 0;
+       return ret;
 }
 
 static int tegra_channel_try_format(struct file *file, void *fh,