[systemd-devel] [PATCH] cryptsetup: check that password is not null

[Greg KH]

On Thu, Jun 12, 2014 at 11:49:35PM +0200, Thomas H.P. Andersen wrote:
> On Thu, Jun 12, 2014 at 11:08 PM, Greg KH <gregkh at linuxfoundation.org> wrote:
> > On Thu, Jun 12, 2014 at 10:55:50PM +0200, Thomas H.P. Andersen wrote:
> >> From: Thomas Hindoe Paaboel Andersen <phomes at gmail.com>
> >>
> >> Beef up the assert to protect against passing null to strlen.
> >>
> >> Found with scan-build.
> >> ---
> >>  src/cryptsetup/cryptsetup.c | 2 +-
> >>  1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/src/cryptsetup/cryptsetup.c b/src/cryptsetup/cryptsetup.c
> >> index 812b32f..a67d85e 100644
> >> --- a/src/cryptsetup/cryptsetup.c
> >> +++ b/src/cryptsetup/cryptsetup.c
> >> @@ -344,7 +344,7 @@ static int attach_tcrypt(struct crypt_device *cd,
> >>
> >>          assert(cd);
> >>          assert(name);
> >> -        assert(key_file || passwords);
> >> +        assert(key_file || (passwords && passwords[0]));
> >
> > Shouldn't strlen of an "empty" string just return 0?
> 
> Passing null to strlen is undefined behavior and seg faults reliably for me.

NULL, yes, but that's already checked.  Passing a string that is "\0"
should work properly, which is all you added the test for here, right?

Oh doh, that's an array of an array, nevermind, the patch is correct,
my fault.

greg k-h