From: Zheyu Ma <zheyuma97@gmail.com>
To: deller@gmx.de
Cc: linux-fbdev@vger.kernel.org, Zheyu Ma <zheyuma97@gmail.com>,
linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: [PATCH 3/7] video: fbdev: kyro: Error out if 'lineclock' equals zero
Date: Mon, 4 Apr 2022 16:47:19 +0800 [thread overview]
Message-ID: <20220404084723.79089-4-zheyuma97@gmail.com> (raw)
In-Reply-To: <20220404084723.79089-1-zheyuma97@gmail.com>
The userspace program could pass any values to the driver through
ioctl() interface. If the driver doesn't check the value of 'lineclock',
it may cause divide error.
Fix this by checking whether 'lineclock' is zero.
The following log reveals it:
[ 33.404918] divide error: 0000 [#1] PREEMPT SMP KASAN PTI
[ 33.404932] RIP: 0010:kyrofb_set_par+0x30d/0xd80
[ 33.404976] Call Trace:
[ 33.404978] <TASK>
[ 33.404987] fb_set_var+0x604/0xeb0
[ 33.405038] do_fb_ioctl+0x234/0x670
[ 33.405083] fb_ioctl+0xdd/0x130
[ 33.405091] do_syscall_64+0x3b/0x90
Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
---
drivers/video/fbdev/kyro/fbdev.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/video/fbdev/kyro/fbdev.c b/drivers/video/fbdev/kyro/fbdev.c
index 25801e8e3f74..d57772f96ad2 100644
--- a/drivers/video/fbdev/kyro/fbdev.c
+++ b/drivers/video/fbdev/kyro/fbdev.c
@@ -494,6 +494,8 @@ static int kyrofb_set_par(struct fb_info *info)
info->var.hsync_len +
info->var.left_margin)) / 1000;
+ if (!lineclock)
+ return -EINVAL;
/* time for a frame in ns (precision in 32bpp) */
frameclock = lineclock * (info->var.yres +
--
2.25.1
next prev parent reply other threads:[~2022-04-04 8:47 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-04 8:47 [PATCH 0/7] Fix divide errors in fbdev drivers Zheyu Ma
2022-04-04 8:47 ` [PATCH 1/7] video: fbdev: i740fb: Error out if 'pixclock' equals zero Zheyu Ma
2022-04-07 19:49 ` Helge Deller
2022-04-08 1:58 ` Zheyu Ma
2022-04-10 9:02 ` Ondrej Zary
2022-04-11 6:18 ` Helge Deller
2022-04-04 8:47 ` [PATCH 2/7] video: fbdev: neofb: Fix the check of 'var->pixclock' Zheyu Ma
2022-04-04 8:47 ` Zheyu Ma [this message]
2022-04-04 8:47 ` [PATCH 4/7] video: fbdev: vt8623fb: Error out if 'pixclock' equals zero Zheyu Ma
2022-04-04 11:47 ` Geert Uytterhoeven
2022-04-04 8:47 ` [PATCH 5/7] video: fbdev: tridentfb: " Zheyu Ma
2022-04-04 8:47 ` [PATCH 6/7] video: fbdev: arkfb: " Zheyu Ma
2022-04-04 15:52 ` Geert Uytterhoeven
2022-04-04 8:47 ` [PATCH 7/7] video: fbdev: s3fb: " Zheyu Ma
2022-04-04 15:52 ` Geert Uytterhoeven
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