From mboxrd@z Thu Jan 1 00:00:00 1970 From: Junio C Hamano Subject: Re: [PATCH v2] revision.c: fix possible null pointer access Date: Mon, 07 Dec 2015 12:31:11 -0800 Message-ID: References: <1449329244-4585-1-git-send-email-stefan.naewe@gmail.com> Mime-Version: 1.0 Content-Type: text/plain Cc: git@vger.kernel.org To: Stefan Naewe X-From: git-owner@vger.kernel.org Mon Dec 07 21:31:19 2015 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1a62RK-0001nK-SJ for gcvg-git-2@plane.gmane.org; Mon, 07 Dec 2015 21:31:19 +0100 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932815AbbLGUbP (ORCPT ); Mon, 7 Dec 2015 15:31:15 -0500 Received: from pb-smtp0.int.icgroup.com ([208.72.237.35]:56740 "EHLO sasl.smtp.pobox.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932690AbbLGUbO (ORCPT ); Mon, 7 Dec 2015 15:31:14 -0500 Received: from sasl.smtp.pobox.com (unknown [127.0.0.1]) by pb-smtp0.pobox.com (Postfix) with ESMTP id 6B6CE32117; Mon, 7 Dec 2015 15:31:13 -0500 (EST) DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; s=sasl; bh=GmAIkVQMT4XvmXvJ7XnZiLw0UFA=; b=ObA8HJ 5nfuo5y4MUpTSznRpVCCXgXknq+Iz4s+RG7XjmX9M0eOh20GCPrR0wvk1M+ByJvV Ot8aB/tNgZdB+a21MH/Npcx3Or8Y+A4XDGMBp78QhRgGbRmYVaqFlrXrHlDQKbJA xHWLwtTe7VEg/WTDhZGziIZbcBdroztXM6TF8= DomainKey-Signature: a=rsa-sha1; c=nofws; d=pobox.com; h=from:to:cc :subject:references:date:in-reply-to:message-id:mime-version :content-type; q=dns; s=sasl; b=GnmrOO90FpDp66ek82tBw7RKHg2A4koM 4paFffg0KTSScnjbAAWa5A1ONybaNW4OdfSyGX54OVjgiihbts1KPcV1yuUYAumD alwPJHyQGAJtjpDoM48Fo3ApDaMc0E38+PTsNVYZPH+HV0vPcg7EksXFQRzePd9N sn0YSQf9c2I= Received: from pb-smtp0.int.icgroup.com (unknown [127.0.0.1]) by pb-smtp0.pobox.com (Postfix) with ESMTP id 6419F32116; Mon, 7 Dec 2015 15:31:13 -0500 (EST) Received: from pobox.com (unknown [216.239.45.64]) (using TLSv1.2 with cipher DHE-RSA-AES128-SHA (128/128 bits)) (No client certificate requested) by pb-smtp0.pobox.com (Postfix) with ESMTPSA id A04AD32113; Mon, 7 Dec 2015 15:31:12 -0500 (EST) In-Reply-To: <1449329244-4585-1-git-send-email-stefan.naewe@gmail.com> (Stefan Naewe's message of "Sat, 5 Dec 2015 16:27:24 +0100") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.3 (gnu/linux) X-Pobox-Relay-ID: 74F9CCEC-9D21-11E5-88D7-6BD26AB36C07-77302942!pb-smtp0.pobox.com Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Stefan Naewe writes: > mark_tree_uninteresting dereferences a tree pointer before checking > if the pointer is valid. Fix that by doing the check first. > > Signed-off-by: Stefan Naewe > --- I still have a problem with "dereferences", as "dereference" is about computing an address and accessing memory based on the result, and only the first half is happening here. I can live with "The function does a pointer arithmetic on 'tree' before it makes sure that 'tree' is not NULL", but in any case, let's queue this as-is for now and wait for a while to see if others can come up with a more appropriate phrases. Thanks. > revision.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/revision.c b/revision.c > index 0fbb684..8c569cc 100644 > --- a/revision.c > +++ b/revision.c > @@ -135,10 +135,12 @@ static void mark_tree_contents_uninteresting(struct tree *tree) > > void mark_tree_uninteresting(struct tree *tree) > { > - struct object *obj = &tree->object; > + struct object *obj; > > if (!tree) > return; > + > + obj = &tree->object; > if (obj->flags & UNINTERESTING) > return; > obj->flags |= UNINTERESTING;