* [PATCH AUTOSEL 4.19 3/5] fbdev: savage: Error out if pixclock equals zero
[not found] <20240202184229.542298-1-sashal@kernel.org>
@ 2024-02-02 18:42 ` Sasha Levin
2024-02-02 18:42 ` [PATCH AUTOSEL 4.19 4/5] fbdev: sis: " Sasha Levin
1 sibling, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2024-02-02 18:42 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Fullway Wang, Helge Deller, Sasha Levin, adaplas, linux-fbdev,
dri-devel
From: Fullway Wang <fullwaywang@outlook.com>
[ Upstream commit 04e5eac8f3ab2ff52fa191c187a46d4fdbc1e288 ]
The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of pixclock,
it may cause divide-by-zero error.
Although pixclock is checked in savagefb_decode_var(), but it is not
checked properly in savagefb_probe(). Fix this by checking whether
pixclock is zero in the function savagefb_check_var() before
info->var.pixclock is used as the divisor.
This is similar to CVE-2022-3061 in i740fb which was fixed by
commit 15cf0b8.
Signed-off-by: Fullway Wang <fullwaywang@outlook.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/video/fbdev/savage/savagefb_driver.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/video/fbdev/savage/savagefb_driver.c b/drivers/video/fbdev/savage/savagefb_driver.c
index c09d7426cd92..d9eafdb89cea 100644
--- a/drivers/video/fbdev/savage/savagefb_driver.c
+++ b/drivers/video/fbdev/savage/savagefb_driver.c
@@ -869,6 +869,9 @@ static int savagefb_check_var(struct fb_var_screeninfo *var,
DBG("savagefb_check_var");
+ if (!var->pixclock)
+ return -EINVAL;
+
var->transp.offset = 0;
var->transp.length = 0;
switch (var->bits_per_pixel) {
--
2.43.0
^ permalink raw reply related [flat|nested] 2+ messages in thread* [PATCH AUTOSEL 4.19 4/5] fbdev: sis: Error out if pixclock equals zero
[not found] <20240202184229.542298-1-sashal@kernel.org>
2024-02-02 18:42 ` [PATCH AUTOSEL 4.19 3/5] fbdev: savage: Error out if pixclock equals zero Sasha Levin
@ 2024-02-02 18:42 ` Sasha Levin
1 sibling, 0 replies; 2+ messages in thread
From: Sasha Levin @ 2024-02-02 18:42 UTC (permalink / raw)
To: linux-kernel, stable
Cc: Fullway Wang, Helge Deller, Sasha Levin, tzimmermann, sam,
javierm, linux-fbdev, dri-devel
From: Fullway Wang <fullwaywang@outlook.com>
[ Upstream commit e421946be7d9bf545147bea8419ef8239cb7ca52 ]
The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of pixclock,
it may cause divide-by-zero error.
In sisfb_check_var(), var->pixclock is used as a divisor to caculate
drate before it is checked against zero. Fix this by checking it
at the beginning.
This is similar to CVE-2022-3061 in i740fb which was fixed by
commit 15cf0b8.
Signed-off-by: Fullway Wang <fullwaywang@outlook.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/video/fbdev/sis/sis_main.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/video/fbdev/sis/sis_main.c b/drivers/video/fbdev/sis/sis_main.c
index 20aff9005978..b7f9da690db2 100644
--- a/drivers/video/fbdev/sis/sis_main.c
+++ b/drivers/video/fbdev/sis/sis_main.c
@@ -1488,6 +1488,8 @@ sisfb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
vtotal = var->upper_margin + var->lower_margin + var->vsync_len;
+ if (!var->pixclock)
+ return -EINVAL;
pixclock = var->pixclock;
if((var->vmode & FB_VMODE_MASK) == FB_VMODE_NONINTERLACED) {
--
2.43.0
^ permalink raw reply related [flat|nested] 2+ messages in thread