releases/4.19.238/video-fbdev-w100fb-reset-global-state.patch

From ab9bfb1764eec6bee5f7215b232bebde488e0147 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Wed, 11 Aug 2021 19:58:26 +0300
Subject: video: fbdev: w100fb: Reset global state

From: Evgeny Novikov <novikov@ispras.ru>

[ Upstream commit 8738ddcac644964ae128ccd3d80d48773c8d528e ]

w100fb_probe() did not reset the global state to its initial state. This
can result in invocation of iounmap() even when there was not the
appropriate successful call of ioremap(). For instance, this may be the
case if first probe fails after two successful ioremap() while second
probe fails when first ioremap() fails. The similar issue is with
w100fb_remove(). The patch fixes both bugs.

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

Signed-off-by: Evgeny Novikov <novikov@ispras.ru>
Co-developed-by: Kirill Shilimanov <kirill.shilimanov@huawei.com>
Signed-off-by: Kirill Shilimanov <kirill.shilimanov@huawei.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/video/fbdev/w100fb.c | 15 ++++++++++++---
 1 file changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/video/fbdev/w100fb.c b/drivers/video/fbdev/w100fb.c
index 967030176d87..307066113c35 100644
--- a/drivers/video/fbdev/w100fb.c
+++ b/drivers/video/fbdev/w100fb.c
@@ -773,12 +773,18 @@ int w100fb_probe(struct platform_device *pdev)
 		fb_dealloc_cmap(&info->cmap);
 		kfree(info->pseudo_palette);
 	}
-	if (remapped_fbuf != NULL)
+	if (remapped_fbuf != NULL) {
 		iounmap(remapped_fbuf);
-	if (remapped_regs != NULL)
+		remapped_fbuf = NULL;
+	}
+	if (remapped_regs != NULL) {
 		iounmap(remapped_regs);
-	if (remapped_base != NULL)
+		remapped_regs = NULL;
+	}
+	if (remapped_base != NULL) {
 		iounmap(remapped_base);
+		remapped_base = NULL;
+	}
 	if (info)
 		framebuffer_release(info);
 	return err;
@@ -803,8 +809,11 @@ static int w100fb_remove(struct platform_device *pdev)
 	fb_dealloc_cmap(&info->cmap);
 
 	iounmap(remapped_base);
+	remapped_base = NULL;
 	iounmap(remapped_regs);
+	remapped_regs = NULL;
 	iounmap(remapped_fbuf);
+	remapped_fbuf = NULL;
 
 	framebuffer_release(info);
 
-- 
2.34.1