[PATCH] media: atomisp: ssh_css: Fix a null-pointer dereference in load_video_binaries

[Zhipeng Lu]

The allocation failure of mycs->yuv_scaler_binary in load_video_binaries
is followed with a dereference of mycs->yuv_scaler_binary after the
following call chain:

sh_css_pipe_load_binaries
  |-> load_video_binaries (mycs->yuv_scaler_binary == NULL)
  |
  |-> sh_css_pipe_unload_binaries
        |-> unload_video_binaries

In unload_video_binaries, it calls to ia_css_binary_unload with argument
&pipe->pipe_settings.video.yuv_scaler_binary[i], which refers to the
same memory slot as mycs->yuv_scaler_binary. Thus, a null-pointer
dereference is triggered.

Fixes: ad85094b293e ("Revert "media: staging: atomisp: Remove driver"")
Signed-off-by: Zhipeng Lu <alexious@xxxxxxxxxx>
---
 drivers/staging/media/atomisp/pci/sh_css.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/media/atomisp/pci/sh_css.c b/drivers/staging/media/atomisp/pci/sh_css.c
index f35c90809414..eb43f4e99d02 100644
--- a/drivers/staging/media/atomisp/pci/sh_css.c
+++ b/drivers/staging/media/atomisp/pci/sh_css.c
@@ -4936,9 +4936,10 @@ unload_video_binaries(struct ia_css_pipe *pipe)
 	ia_css_binary_unload(&pipe->pipe_settings.video.video_binary);
 	ia_css_binary_unload(&pipe->pipe_settings.video.vf_pp_binary);
 
-	for (i = 0; i < pipe->pipe_settings.video.num_yuv_scaler; i++)
-		ia_css_binary_unload(&pipe->pipe_settings.video.yuv_scaler_binary[i]);
-
+	if (pipe->pipe_settings.video.yuv_scaler_binary)
+		for (i = 0; i < pipe->pipe_settings.video.num_yuv_scaler; i++)
+			ia_css_binary_unload(&pipe->pipe_settings.video.yuv_scaler_binary[i]);
+		
 	kfree(pipe->pipe_settings.video.is_output_stage);
 	pipe->pipe_settings.video.is_output_stage = NULL;
 	kfree(pipe->pipe_settings.video.yuv_scaler_binary);
-- 
2.34.1