[PATCH AUTOSEL for 4.9 139/190] sm501fb: don't return zero on failure path in sm501fb_start()

[Sasha Levin]

From: Alexey Khoroshilov <khoroshilov@xxxxxxxxx>

[ Upstream commit dc85e9a87420613b3129d5cc5ecd79c58351c546 ]

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@xxxxxxxxx>
Cc: Tomi Valkeinen <tomi.valkeinen@xxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 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 d0a4e2f79a57..d215faacce04 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;
 	}
 
-- 
2.14.1