From: Danila Chernetsov <listdansp@mail.ru>
Date: Wed, 19 Mar 2025 01:30:11 +0000 (+0000)
Subject: fbdev: sm501fb: Add some geometry checks.
X-Git-Tag: v6.12.23~330
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=238ece4937aa5f103bc65b55678b2b1b2700c3f8;p=thirdparty%2Fkernel%2Fstable.git

fbdev: sm501fb: Add some geometry checks.

[ Upstream commit aee50bd88ea5fde1ff4cc021385598f81a65830c ]

Added checks for xoffset, yoffset settings.
Incorrect settings of these parameters can lead to errors
in sm501fb_pan_ functions.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 5fc404e47bdf ("[PATCH] fb: SM501 framebuffer driver")
Signed-off-by: Danila Chernetsov <listdansp@mail.ru>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/video/fbdev/sm501fb.c b/drivers/video/fbdev/sm501fb.c
index 86ecbb2d86db8..2eb27ebf822e8 100644
--- a/drivers/video/fbdev/sm501fb.c
+++ b/drivers/video/fbdev/sm501fb.c
@@ -326,6 +326,13 @@ static int sm501fb_check_var(struct fb_var_screeninfo *var,
 	if (var->xres_virtual > 4096 || var->yres_virtual > 2048)
 		return -EINVAL;
 
+	/* geometry sanity checks */
+	if (var->xres + var->xoffset > var->xres_virtual)
+		return -EINVAL;
+
+	if (var->yres + var->yoffset > var->yres_virtual)
+		return -EINVAL;
+
 	/* can cope with 8,16 or 32bpp */
 
 	if (var->bits_per_pixel <= 8)