[PATCH 5.4 100/154] fbdev: sm501fb: Add some geometry checks.

Greg Kroah-Hartman
2025-04-08T12:06:44Z

From: Danila Chernetsov <listdansp@mail.ru>

[ 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>
---
drivers/video/fbdev/sm501fb.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/drivers/video/fbdev/sm501fb.c b/drivers/video/fbdev/sm501fb.c
index 3dd1b1d76e983..a7acf0acd3e92 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)
--
2.39.5