linux-kernel - [PATCH] m501fb: don't return zero on failure path in sm501fb

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Date:   Sat, 29 Apr 2017 21:33:39 +0200
From:   Alexey Khoroshilov <khoroshilov@...ras.ru>
To:     Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Tomi Valkeinen <tomi.valkeinen@...com>
Cc:     Alexey Khoroshilov <khoroshilov@...ras.ru>,
        linux-fbdev@...r.kernel.org, linux-kernel@...r.kernel.org,
        ldv-project@...uxtesting.org
Subject: [PATCH] m501fb: don't return zero on failure path in sm501fb_start()

If fbmem iomemory mapping failed, sm501fb_start() breaks off
initialization, deallocates resources, but returns zero.
As a result, double deallocation can happen in sm501fb_stop().

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

Signed-off-by: Alexey Khoroshilov <khoroshilov@...ras.ru>
---
 drivers/video/fbdev/sm501fb.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/video/fbdev/sm501fb.c b/drivers/video/fbdev/sm501fb.c
index d80bc8a3200f..67e314fdd947 100644
--- a/drivers/video/fbdev/sm501fb.c
+++ b/drivers/video/fbdev/sm501fb.c
@@ -1600,6 +1600,7 @@ static int sm501fb_start(struct sm501fb_info *info,
 	info->fbmem = ioremap(res->start, resource_size(res));
 	if (info->fbmem == NULL) {
 		dev_err(dev, "cannot remap framebuffer\n");
+		ret = -ENXIO;
 		goto err_mem_res;
 	}
 
-- 
2.7.4