From patchwork Fri Mar 8 20:46:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 31790 Received: (qmail 21571 invoked by alias); 8 Mar 2019 20:46:25 -0000 Mailing-List: contact libc-alpha-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: libc-alpha-owner@sourceware.org Delivered-To: mailing list libc-alpha@sourceware.org Received: (qmail 21203 invoked by uid 89); 8 Mar 2019 20:46:16 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-20.7 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, SPF_HELO_PASS autolearn=ham version=3.3.1 spammy= X-HELO: mx1.redhat.com Date: Fri, 08 Mar 2019 21:46:12 +0100 To: libc-alpha@sourceware.org Subject: [PATCH] nss_dns: Adjust ns_name_ntop failure handling in getnetby* User-Agent: Heirloom mailx 12.5 7/5/10 MIME-Version: 1.0 Message-Id: <20190308204612.5537780DD6B5@oldenburg2.str.redhat.com> From: Florian Weimer If the function fails, the output buffer is not large enough. The function does not fail for any other reason. 2019-03-08 Florian Weimer * resolv/nss_dns/dns-network.c (getanswer_r): On ns_name_ntop failure, the buffer is always too small. diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c index 68266d57c9..9b75ac8233 100644 --- a/resolv/nss_dns/dns-network.c +++ b/resolv/nss_dns/dns-network.c @@ -324,19 +324,14 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result, { int n = __ns_name_unpack (answer->buf, end_of_message, cp, packtmp, sizeof packtmp); - if (n != -1 && __ns_name_ntop (packtmp, bp, linebuflen) == -1) - { - if (errno == EMSGSIZE) - goto too_small; - - n = -1; - } - - if (n > 0 && bp[0] == '.') - bp[0] = '\0'; - if (n < 0) goto bad_message; + if (__ns_name_ntop (packtmp, bp, linebuflen) < 0) + goto too_small; + + if (bp[0] == '.') + bp[0] = '\0'; + cp += n; if (end_of_message - cp < 10) @@ -355,16 +350,11 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result, { n = __ns_name_unpack (answer->buf, end_of_message, cp, packtmp, sizeof packtmp); - if (n != -1 && __ns_name_ntop (packtmp, bp, linebuflen) == -1) - { - if (errno == EMSGSIZE) - goto too_small; - - n = -1; - } - if (n < 0) goto bad_message; + if (__ns_name_ntop (packtmp, bp, linebuflen) < 0) + goto too_small; + cp += rdatalen; if (alias_pointer + 2 < &net_data->aliases[MAX_NR_ALIASES]) {