Messages in this thread | | | Date | Wed, 7 Sep 2011 17:06:21 -0700 | From | Andrew Morton <> | Subject | Re: [PATCH][REPOST] Check maxlen on strnlen_user usage |
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On Thu, 08 Sep 2011 09:54:18 +1000 Ryan Mallon <rmallon@gmail.com> wrote:
> strnlen_user returns the length of the string including the nul > terminator. In the case where maxlen is reached strnlen_user returns > maxlen + 1. Most callsites already check for this condition. Fix the > call to strnlen_user in fs/exec.c to check for the maxlen case. > > diff --git a/fs/exec.c b/fs/exec.c > index 25dcbe5..e19588c 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -481,7 +481,7 @@ static int copy_strings(int argc, struct > user_arg_ptr argv, > goto out; > > len = strnlen_user(str, MAX_ARG_STRLEN); > - if (!len) > + if (!len || len> MAX_ARG_STRLEN) > goto out; > > ret = -E2BIG;
The following call to vald_arg_len() already does this?
This change will cause copy_strings() to incorrectly return -EFAULT, rather than -E2BIG.
Your email client is wordwrapping and space-stuffing the patches, btw.
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