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From: Zhipeng Lu <alexious@zju.edu.cn>
To: alexious@zju.edu.cn
Cc: Hans de Goede <hdegoede@redhat.com>,
	Mauro Carvalho Chehab <mchehab@kernel.org>,
	Sakari Ailus <sakari.ailus@linux.intel.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	Kate Hsuan <hpa@redhat.com>,
	Andy Shevchenko <andy.shevchenko@gmail.com>,
	Dan Carpenter <error27@gmail.com>,
	Brent Pappas <bpappas@pappasbrent.com>,
	linux-media@vger.kernel.org,
	linux-staging@lists.linux.dev,
	linux-kernel@vger.kernel.org
Subject: [PATCH] media: atomisp: ssh_css: Fix a null-pointer dereference in load_video_binaries
Date: Fri, 12 Jan 2024 16:34:19 +0800
Message-Id: <20240112083421.3728017-1-alexious@zju.edu.cn>
Precedence: bulk
MIME-Version: 1.0
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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@zju.edu.cn>
---
 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