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From:   Evgeny Novikov <novikov@ispras.ru>
To:     Antoine Jacquet <royale@zerezo.com>
Cc:     Evgeny Novikov <novikov@ispras.ru>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-usb@vger.kernel.org, linux-media@vger.kernel.org,
        linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org
Subject: [PATCH] media: zr364xx: propagate errors from zr364xx_start_readpipe()
Date:   Tue,  6 Oct 2020 20:21:22 +0300
Message-Id: <20201006172122.25038-1-novikov@ispras.ru>
Precedence: bulk

zr364xx_start_readpipe() can fail but callers do not care about that.
This can result in various negative consequences. The patch adds missed
error handling.

Found by Linux Driver Verification project (linuxtesting.org).

Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
---
 drivers/media/usb/zr364xx/zr364xx.c | 31 ++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/drivers/media/usb/zr364xx/zr364xx.c b/drivers/media/usb/zr364xx/zr364xx.c
index 8c670934d920..d65d3c2a034e 100644
--- a/drivers/media/usb/zr364xx/zr364xx.c
+++ b/drivers/media/usb/zr364xx/zr364xx.c
@@ -1327,6 +1327,7 @@ static int zr364xx_board_init(struct zr364xx_camera *cam)
 {
 	struct zr364xx_pipeinfo *pipe = cam->pipe;
 	unsigned long i;
+	int err;
 
 	DBG("board init: %p\n", cam);
 	memset(pipe, 0, sizeof(*pipe));
@@ -1359,9 +1360,8 @@ static int zr364xx_board_init(struct zr364xx_camera *cam)
 
 	if (i == 0) {
 		printk(KERN_INFO KBUILD_MODNAME ": out of memory. Aborting\n");
-		kfree(cam->pipe->transfer_buffer);
-		cam->pipe->transfer_buffer = NULL;
-		return -ENOMEM;
+		err = -ENOMEM;
+		goto err_free;
 	} else
 		cam->buffer.dwFrames = i;
 
@@ -1376,9 +1376,17 @@ static int zr364xx_board_init(struct zr364xx_camera *cam)
 	/*** end create system buffers ***/
 
 	/* start read pipe */
-	zr364xx_start_readpipe(cam);
+	err = zr364xx_start_readpipe(cam);
+	if (err)
+		goto err_free;
+
 	DBG(": board initialized\n");
 	return 0;
+
+err_free:
+	kfree(cam->pipe->transfer_buffer);
+	cam->pipe->transfer_buffer = NULL;
+	return err;
 }
 
 static int zr364xx_probe(struct usb_interface *intf,
@@ -1575,10 +1583,19 @@ static int zr364xx_resume(struct usb_interface *intf)
 	if (!cam->was_streaming)
 		return 0;
 
-	zr364xx_start_readpipe(cam);
+	res = zr364xx_start_readpipe(cam);
+	if (res)
+		return res;
+
 	res = zr364xx_prepare(cam);
-	if (!res)
-		zr364xx_start_acquire(cam);
+	if (res)
+		goto err_prepare;
+
+	zr364xx_start_acquire(cam);
+	return 0;
+
+err_prepare:
+	zr364xx_stop_readpipe(cam);
 	return res;
 }
 #endif
-- 
2.26.2