[PATCH 4.9 122/177] sm501fb: dont return zero on failure path in sm501fb_start()

From: Greg Kroah-Hartman
Date: Fri Mar 23 2018 - 06:10:20 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/video/fbdev/sm501fb.c | 1 +
1 file changed, 1 insertion(+)

--- a/drivers/video/fbdev/sm501fb.c
+++ b/drivers/video/fbdev/sm501fb.c
@@ -1600,6 +1600,7 @@ static int sm501fb_start(struct sm501fb_
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;
}