[PATCH AUTOSEL 4.9 84/91] fbtft: Make sure string is NULL terminated

[Sasha Levin]

From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

[ Upstream commit 21f585480deb4bcf0d92b08879c35d066dfee030 ]

New GCC warns about inappropriate use of strncpy():

drivers/staging/fbtft/fbtft-core.c: In function âfbtft_framebuffer_allocâ:
drivers/staging/fbtft/fbtft-core.c:665:2: warning: âstrncpyâ specified bound 16 equals destination size [-Wstringop-truncation]
  665 |  strncpy(info->fix.id, dev->driver->name, 16);
      |  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Later on the copy is being used with the assumption to be NULL terminated.
Make sure string is NULL terminated by switching to snprintf().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20191120095716.26628-1-andriy.shevchenko@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/staging/fbtft/fbtft-core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
index d9ba8c0f1353b..ece713d026607 100644
--- a/drivers/staging/fbtft/fbtft-core.c
+++ b/drivers/staging/fbtft/fbtft-core.c
@@ -766,7 +766,7 @@ struct fb_info *fbtft_framebuffer_alloc(struct fbtft_display *display,
 	fbdefio->deferred_io =     fbtft_deferred_io;
 	fb_deferred_io_init(info);
 
-	strncpy(info->fix.id, dev->driver->name, 16);
+	snprintf(info->fix.id, sizeof(info->fix.id), "%s", dev->driver->name);
 	info->fix.type =           FB_TYPE_PACKED_PIXELS;
 	info->fix.visual =         FB_VISUAL_TRUECOLOR;
 	info->fix.xpanstep =	   0;
-- 
2.20.1