From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 51C168489 for ; Fri, 10 Mar 2023 14:16:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id CC310C433EF; Fri, 10 Mar 2023 14:16:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678457775; bh=r3R0pKyDDLULWjJjRmPaBgwtEd0dbnEJV2wAA1P6tEE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V++u5FxOvVpcNnsTLx1QWgVjXruNQmfQ4npAJDtuQCVfvfVRwTFr8OX2SHu4G5GtQ Epa39JvA7mkVV51j/VZCrgaLhgd1ZvESJuOS5u2oCk/3XsiiEGiScJ1qkfJ7HXWti/ e2uHjE47flyUiAtDtgyOZiXCZAgc5ZIdxyKhg1kE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Ilya Leoshkevich , Andrii Nakryiko , Sasha Levin Subject: [PATCH 4.19 052/252] libbpf: Fix alen calculation in libbpf_nla_dump_errormsg() Date: Fri, 10 Mar 2023 14:37:02 +0100 Message-Id: <20230310133720.384966750@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230310133718.803482157@linuxfoundation.org> References: <20230310133718.803482157@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ilya Leoshkevich [ Upstream commit 17bcd27a08a21397698edf143084d7c87ce17946 ] The code assumes that everything that comes after nlmsgerr are nlattrs. When calculating their size, it does not account for the initial nlmsghdr. This may lead to accessing uninitialized memory. Fixes: bbf48c18ee0c ("libbpf: add error reporting in XDP") Signed-off-by: Ilya Leoshkevich Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230210001210.395194-8-iii@linux.ibm.com Signed-off-by: Sasha Levin --- tools/lib/bpf/nlattr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/lib/bpf/nlattr.c b/tools/lib/bpf/nlattr.c index 4719434278b20..ac979b4290559 100644 --- a/tools/lib/bpf/nlattr.c +++ b/tools/lib/bpf/nlattr.c @@ -170,7 +170,7 @@ int nla_dump_errormsg(struct nlmsghdr *nlh) hlen += nlmsg_len(&err->msg); attr = (struct nlattr *) ((void *) err + hlen); - alen = nlh->nlmsg_len - hlen; + alen = (void *)nlh + nlh->nlmsg_len - (void *)attr; if (nla_parse(tb, NLMSGERR_ATTR_MAX, attr, alen, extack_policy) != 0) { fprintf(stderr, -- 2.39.2