On 09/03/15 20:08, Matteo Semenzato wrote:
From: Matteo Semenzato <mattew8...@gmail.com>

The comedi_cmd struct has an hole after chanlist_len that could contain 
uninitialized
memory, this struct is copied to userspace.

Signed-off-by: Matteo Semenato <mattew8...@gmail.com>
---
  drivers/staging/comedi/comedi_fops.c | 2 ++
  1 file changed, 2 insertions(+)

diff --git a/drivers/staging/comedi/comedi_fops.c 
b/drivers/staging/comedi/comedi_fops.c
index 727640e..1cdf0a2 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -1718,6 +1718,8 @@ static int do_cmdtest_ioctl(struct comedi_device *dev,
        unsigned int __user *user_chanlist;
        int ret;

+       memset(&cmd, 0, sizeof(cmd));
+
        /* get the user's cmd and do some simple validation */
        ret = __comedi_get_user_cmd(dev, arg, &cmd);
        if (ret)


I see no information leak there. The cmd variable gets copied over with user memory by the call to __comedi_get_user_cmd(), so zero-filling it first is rather pointless.

--
-=( Ian Abbott @ MEV Ltd.    E-mail: <abbo...@mev.co.uk> )=-
-=(                          Web: http://www.mev.co.uk/  )=-
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