linux-kernel - [PATCH] [video/fbdev] mbxfb_remove: fix null pointer dereference

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Date:   Sun, 26 Jul 2020 01:20:45 -0400
From:   Gaurav Singh <gaurav1086@...il.com>
To:     gaurav1086@...il.com,
        Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>,
        Arnd Bergmann <arnd@...db.de>,
        Daniel Vetter <daniel.vetter@...ll.ch>,
        Jani Nikula <jani.nikula@...el.com>,
        dri-devel@...ts.freedesktop.org (open list:FRAMEBUFFER LAYER),
        linux-fbdev@...r.kernel.org (open list:FRAMEBUFFER LAYER),
        linux-kernel@...r.kernel.org (open list)
Subject: [PATCH] [video/fbdev] mbxfb_remove: fix null pointer dereference

Function mbxfb_debugfs_remove() accesses fbi->par without NULL check,
hence do the NULL check in the caller mbxfb_remove().

Signed-off-by: Gaurav Singh <gaurav1086@...il.com>
---
 drivers/video/fbdev/mbx/mbxfb.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/mbx/mbxfb.c b/drivers/video/fbdev/mbx/mbxfb.c
index 6dc287c819cb..515c0cda1994 100644
--- a/drivers/video/fbdev/mbx/mbxfb.c
+++ b/drivers/video/fbdev/mbx/mbxfb.c
@@ -1012,11 +1012,10 @@ static int mbxfb_remove(struct platform_device *dev)
 
 	write_reg_dly(SYSRST_RST, SYSRST);
 
-	mbxfb_debugfs_remove(fbi);
-
 	if (fbi) {
 		struct mbxfb_info *mfbi = fbi->par;
 
+		mbxfb_debugfs_remove(fbi);
 		unregister_framebuffer(fbi);
 		if (mfbi) {
 			if (mfbi->platform_remove)
-- 
2.17.1