From: Vasiliy Kulikov <segoon@openwall.com>
To: kernel-janitors@vger.kernel.org
Cc: Jaya Kumar <jayalk@intworks.biz>,
linux-fbdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] video: arcfb: fix buffer overflow
Date: Sun, 21 Nov 2010 17:40:01 +0000 [thread overview]
Message-ID: <1290361202-15065-1-git-send-email-segoon@openwall.com> (raw)
(count + p) is not checked for integer overflow. If p < fbmemlength
and count = (size_t)(1 - p) (very big unsigned integer) then
count + p = 1 < fbmemlength and copy_to_user(base_addr+p, buf, count)
overflows base_addr.
Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
---
Compile tested only.
drivers/video/arcfb.c | 2 +-
1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/drivers/video/arcfb.c b/drivers/video/arcfb.c
index 3ec4923..67a4cd4 100644
--- a/drivers/video/arcfb.c
+++ b/drivers/video/arcfb.c
@@ -454,7 +454,7 @@ static ssize_t arcfb_write(struct fb_info *info, const char __user *buf,
xres = info->var.xres;
fbmemlength = (xres * info->var.yres)/8;
- if (p > fbmemlength)
+ if (p > fbmemlength || (p + count < p))
return -ENOSPC;
err = 0;
--
1.7.0.4
next reply other threads:[~2010-11-21 17:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-21 17:40 Vasiliy Kulikov [this message]
2010-11-24 6:25 ` [PATCH] video: arcfb: fix buffer overflow Paul Mundt
2010-11-24 6:46 ` Dan Carpenter
2010-11-24 6:59 ` Paul Mundt
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