From patchwork Fri Mar 8 20:45:12 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Florian Weimer X-Patchwork-Id: 31789 Received: (qmail 19796 invoked by alias); 8 Mar 2019 20:45:42 -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 19631 invoked by uid 89); 8 Mar 2019 20:45:20 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-19.8 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=consistently X-HELO: mx1.redhat.com Date: Fri, 08 Mar 2019 21:45:12 +0100 To: libc-alpha@sourceware.org Subject: [PATCH] nss_dns: More consistency in corrupt message handling in getnetby* User-Agent: Heirloom mailx 12.5 7/5/10 MIME-Version: 1.0 Message-Id: <20190308204512.4EC1780DD6B5@oldenburg2.str.redhat.com> From: Florian Weimer If a parse error is encountered, fail with NO_RECOVERY and NSS_STATUS_UNAVAIL. 2019-03-08 Florian Weimer * resolv/nss_dns/dns-network.c (getanswer_r): Handle unparseable messages more consistently. diff --git a/resolv/nss_dns/dns-network.c b/resolv/nss_dns/dns-network.c index 9c0082d270..68266d57c9 100644 --- a/resolv/nss_dns/dns-network.c +++ b/resolv/nss_dns/dns-network.c @@ -336,14 +336,11 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result, bp[0] = '\0'; if (n < 0) - break; + goto bad_message; cp += n; if (end_of_message - cp < 10) - { - __set_h_errno (NO_RECOVERY); - return NSS_STATUS_UNAVAIL; - } + goto bad_message; int type, class; GETSHORT (type, cp); @@ -352,10 +349,7 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result, uint16_t rdatalen; GETSHORT (rdatalen, cp); if (end_of_message - cp < rdatalen) - { - __set_h_errno (NO_RECOVERY); - return NSS_STATUS_UNAVAIL; - } + goto bad_message; if (class == C_IN && type == T_PTR) { @@ -370,13 +364,7 @@ getanswer_r (const querybuf *answer, int anslen, struct netent *result, } if (n < 0) - { - /* XXX What does this mean? The original form from bind - returns NULL. Incrementing cp has no effect in any case. - What should I return here. ??? */ - cp += n; - return NSS_STATUS_UNAVAIL; - } + goto bad_message; cp += rdatalen; if (alias_pointer + 2 < &net_data->aliases[MAX_NR_ALIASES]) {