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 23430BA45 for ; Tue, 7 Mar 2023 18:09:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9482EC4339C; Tue, 7 Mar 2023 18:09:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678212550; bh=7IDupy/uympF3yiDf3YB1jvkydvCTx1b3QoNG5dHuEs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cFO5mc9w31uR/DWyCej6PPepVDbpVJTI7lM4AHh2KrA6ZvoaZr2BhnsZ+hPkC1u7r SXy4x56s50ouymFOe7fablpLgYUFNz4WrIhQ7NkXI1M6Bi3FpGK3z5VaG38XbIwc85 KjZ1A3WIjOv7maN3QVnV40I5/FDjJPzjhtal8+kg= 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 6.1 220/885] libbpf: Fix alen calculation in libbpf_nla_dump_errormsg() Date: Tue, 7 Mar 2023 17:52:34 +0100 Message-Id: <20230307170011.650376326@linuxfoundation.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230307170001.594919529@linuxfoundation.org> References: <20230307170001.594919529@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 3900d052ed19e..975e265eab3bf 100644 --- a/tools/lib/bpf/nlattr.c +++ b/tools/lib/bpf/nlattr.c @@ -178,7 +178,7 @@ 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