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From: Vasiliy Kulikov <segoon@openwall.com>
To: kernel-janitors@vger.kernel.org
Cc: Dave Airlie <airlied@redhat.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Tiago Vignatti <tiago.vignatti@nokia.com>,
	Mike Travis <travis@sgi.com>, "H. Peter Anvin" <hpa@zytor.com>,
	linux-kernel@vger.kernel.org
Subject: [PATCH v2] gpu: vga: limit kmalloc'ed memory size
Date: Mon, 22 Nov 2010 17:11:03 +0000	[thread overview]
Message-ID: <1290445864-13657-1-git-send-email-segoon@openwall.com> (raw)

count is not checked before kmalloc() call.  Too big value would
generate stack dump.  To prevent this limit 'count' maximum value.
1024 looks OK - the data should be the string of tens of bytes.

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
---
 Compile tested only.

 v1 had incorrect comment text, as Dan Rosenberg noticed.

 drivers/gpu/vga/vgaarb.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/drivers/gpu/vga/vgaarb.c b/drivers/gpu/vga/vgaarb.c
index c380c65..09e3090 100644
--- a/drivers/gpu/vga/vgaarb.c
+++ b/drivers/gpu/vga/vgaarb.c
@@ -836,6 +836,8 @@ static ssize_t vga_arb_write(struct file *file, const char __user * buf,
 	int ret_val;
 	int i;
 
+	if (count > 1024)
+		count = 1024;
 
 	kbuf = kmalloc(count + 1, GFP_KERNEL);
 	if (!kbuf)
-- 
1.7.0.4


             reply	other threads:[~2010-11-22 17:11 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2010-11-22 17:11 Vasiliy Kulikov [this message]
2010-11-22 18:09 ` [PATCH v2] gpu: vga: limit kmalloc'ed memory size Andrew Morton
2010-11-23 19:08   ` Vasiliy Kulikov
2010-11-23 20:46     ` Andrew Morton
2010-11-24 18:33       ` Vasiliy Kulikov

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