From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Carpenter Date: Fri, 23 Jul 2010 11:47:06 +0000 Subject: [patch] message/i2o: add sanity check Message-Id: <20100723114706.GH26313@bicker> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-kernel@vger.kernel.org, Markus.Lidel@shadowconnect.com Cc: kernel-janitors@vger.kernel.org We use "reply_size" to determine the size of the "reply" buffer. These days the "reply" buffer is just some context information, an error code, and a bunch of zeroes. We stopped using it for useful information four years ago in dcceafe25a5f47 "[PATCH] I2O: Bugfixes" This patch ensures that "reply" is large enough to hold the context information. In the current code if "reply_size" is zero that would cause memory corruption when we save the error code: reply[4] = ((u32) rcode) << 24; Signed-off-by: Dan Carpenter diff --git a/drivers/message/i2o/i2o_config.c b/drivers/message/i2o/i2o_config.c index c4b117f..8b1d55e 100644 --- a/drivers/message/i2o/i2o_config.c +++ b/drivers/message/i2o/i2o_config.c @@ -817,6 +817,11 @@ static int i2o_cfg_passthru(unsigned long arg) reply_size >>= 16; reply_size <<= 2; + if (reply_size < 5 * sizeof(u32)) { + rcode = -EINVAL; + goto out; + } + reply = kzalloc(reply_size, GFP_KERNEL); if (!reply) { printk(KERN_WARNING "%s: Could not allocate reply buffer\n",