On Tue, 31 Jan 2012 14:25:08 +0300 Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > On Tue, Jan 31, 2012 at 05:49:37AM -0500, Jeff Layton wrote: > > On Tue, 31 Jan 2012 11:52:01 +0300 > > Dan Carpenter <dan.carpenter@xxxxxxxxxx> wrote: > > > > > We should check that we're not copying memory from beyond the end of the > > > blob. > > > > > > Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> > > > > > > diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c > > > index d85efad..eb76741 100644 > > > --- a/fs/cifs/sess.c > > > +++ b/fs/cifs/sess.c > > > @@ -395,6 +395,10 @@ static int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len, > > > ses->ntlmssp->server_flags = le32_to_cpu(pblob->NegotiateFlags); > > > tioffset = le32_to_cpu(pblob->TargetInfoArray.BufferOffset); > > > tilen = le16_to_cpu(pblob->TargetInfoArray.Length); > > > + if (tioffset > blob_len || tioffset + tilen > blob_len) { > > > + cERROR(1, "tioffset + tilen too high %u + %u", tioffset, tilen); > > > + return -EINVAL; > > > + } > > > > Good catch. > > > > Do we really need a || here though? Would it not be sufficient to check > > if tioffset + tilen > blob_len? Or are you concerned about that value > > wrapping? > > Yep. I was concerned about value wrapping. > > regards, > dan carpenter > Seems reasonable then. Thanks... Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
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