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 A281E848D for ; Fri, 10 Mar 2023 14:29:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2B011C433D2; Fri, 10 Mar 2023 14:29:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678458592; bh=Az3N/3XPSg9v745Mfocz9qQnO+r1aek9yqfMVuJ3a/w=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WEXKmhamo06VfdL7wZjqNgkAd4gcOdvmHU0ARpgwj7D0qCK0ktzHt5BDj6Hsp92xt KxdnkPwbZB2VKTdkcunFnstbc/NkmKn1uRIV5HCT/bO92p8rdDDmD6Q8rlLZvl/WNS ycWyg8HevZty99pFlwaq6yb0Dlwu8ZxM7qmxJutQ= 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 5.4 078/357] libbpf: Fix alen calculation in libbpf_nla_dump_errormsg() Date: Fri, 10 Mar 2023 14:36:07 +0100 Message-Id: <20230310133737.425071271@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230310133733.973883071@linuxfoundation.org> References: <20230310133733.973883071@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 1e69c0c8d413f..e610becd03e85 100644 --- a/tools/lib/bpf/nlattr.c +++ b/tools/lib/bpf/nlattr.c @@ -177,7 +177,7 @@ int libbpf_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 (libbpf_nla_parse(tb, NLMSGERR_ATTR_MAX, attr, alen, extack_policy) != 0) { -- 2.39.2