From patchwork Thu May 27 18:32:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Scott Mayhew X-Patchwork-Id: 12285091 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 15851C47089 for ; Thu, 27 May 2021 18:32:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EAA50613D3 for ; Thu, 27 May 2021 18:32:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235783AbhE0SeQ (ORCPT ); Thu, 27 May 2021 14:34:16 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:56154 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234155AbhE0SeQ (ORCPT ); Thu, 27 May 2021 14:34:16 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1622140362; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8xMY4lDW+kazwRYs3gnhaN1WpUl2Eg5FQN7ELoY4IZc=; b=VWhG9kFyiVcKQsuBOI2W8h2DMUrkLUUBa6Ag40ho9Zhhxpp5AlCHI5MIKYM5MZ3LlzGCpl sBUqnFm7NuJ1sSr4wwZ2FOWg+PjkqDqCm4jLphFYsKsevN4lxHJSdr2Ili8X3u9ub1Lp+m kXk+m1Rt5JmXWVyCLfY+9hScH6FiEsg= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-472-0aE2Q1ohMjWDWJ1ZEgWkfw-1; Thu, 27 May 2021 14:32:40 -0400 X-MC-Unique: 0aE2Q1ohMjWDWJ1ZEgWkfw-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 019F91903101 for ; Thu, 27 May 2021 18:32:40 +0000 (UTC) Received: from aion.usersys.redhat.com (ovpn-114-18.rdu2.redhat.com [10.10.114.18]) by smtp.corp.redhat.com (Postfix) with ESMTPS id C45C1163CB for ; Thu, 27 May 2021 18:32:39 +0000 (UTC) Received: by aion.usersys.redhat.com (Postfix, from userid 1000) id 038DD1A0026; Thu, 27 May 2021 14:32:39 -0400 (EDT) From: Scott Mayhew To: linux-nfs@vger.kernel.org Subject: [nfs-utils PATCH v2 1/2] gssd: deal with failed thread creation Date: Thu, 27 May 2021 14:32:37 -0400 Message-Id: <20210527183238.584349-2-smayhew@redhat.com> In-Reply-To: <20210527183238.584349-1-smayhew@redhat.com> References: <20210527183238.584349-1-smayhew@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org If we fail to create a thread to handle an upcall, we still need to do a downcall to tell the kernel about the failure, otherwise the process that is trying to establish gss credentials will hang. This patch shifts the thread creation down a level in the call chain so now the main thread does a little more work up front (reading & parsing the data from the pipefs file) so it has the info it needs to be able to do the error downcall. Signed-off-by: Scott Mayhew --- utils/gssd/gssd.c | 83 +----------------- utils/gssd/gssd.h | 11 ++- utils/gssd/gssd_proc.c | 188 +++++++++++++++++++++++++++++++++-------- 3 files changed, 164 insertions(+), 118 deletions(-) diff --git a/utils/gssd/gssd.c b/utils/gssd/gssd.c index 1541d371..eb440470 100644 --- a/utils/gssd/gssd.c +++ b/utils/gssd/gssd.c @@ -364,7 +364,7 @@ out: /* Actually frees clp and fields that might be used from other * threads if was last reference. */ -static void +void gssd_free_client(struct clnt_info *clp) { int refcnt; @@ -416,55 +416,6 @@ gssd_destroy_client(struct clnt_info *clp) static void gssd_scan(void); -static int -start_upcall_thread(void (*func)(struct clnt_upcall_info *), void *info) -{ - pthread_attr_t attr; - pthread_t th; - int ret; - - ret = pthread_attr_init(&attr); - if (ret != 0) { - printerr(0, "ERROR: failed to init pthread attr: ret %d: %s\n", - ret, strerror(errno)); - return ret; - } - ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); - if (ret != 0) { - printerr(0, "ERROR: failed to create pthread attr: ret %d: " - "%s\n", ret, strerror(errno)); - return ret; - } - - ret = pthread_create(&th, &attr, (void *)func, (void *)info); - if (ret != 0) - printerr(0, "ERROR: pthread_create failed: ret %d: %s\n", - ret, strerror(errno)); - return ret; -} - -static struct clnt_upcall_info *alloc_upcall_info(struct clnt_info *clp) -{ - struct clnt_upcall_info *info; - - info = malloc(sizeof(struct clnt_upcall_info)); - if (info == NULL) - return NULL; - - pthread_mutex_lock(&clp_lock); - clp->refcount++; - pthread_mutex_unlock(&clp_lock); - info->clp = clp; - - return info; -} - -void free_upcall_info(struct clnt_upcall_info *info) -{ - gssd_free_client(info->clp); - free(info); -} - /* For each upcall read the upcall info into the buffer, then create a * thread in a detached state so that resources are released back into * the system without the need for a join. @@ -473,44 +424,16 @@ static void gssd_clnt_gssd_cb(int UNUSED(fd), short UNUSED(which), void *data) { struct clnt_info *clp = data; - struct clnt_upcall_info *info; - - info = alloc_upcall_info(clp); - if (info == NULL) - return; - info->lbuflen = read(clp->gssd_fd, info->lbuf, sizeof(info->lbuf)); - if (info->lbuflen <= 0 || info->lbuf[info->lbuflen-1] != '\n') { - printerr(0, "WARNING: %s: failed reading request\n", __func__); - free_upcall_info(info); - return; - } - info->lbuf[info->lbuflen-1] = 0; - - if (start_upcall_thread(handle_gssd_upcall, info)) - free_upcall_info(info); + handle_gssd_upcall(clp); } static void gssd_clnt_krb5_cb(int UNUSED(fd), short UNUSED(which), void *data) { struct clnt_info *clp = data; - struct clnt_upcall_info *info; - - info = alloc_upcall_info(clp); - if (info == NULL) - return; - - if (read(clp->krb5_fd, &info->uid, - sizeof(info->uid)) < (ssize_t)sizeof(info->uid)) { - printerr(0, "WARNING: %s: failed reading uid from krb5 " - "upcall pipe: %s\n", __func__, strerror(errno)); - free_upcall_info(info); - return; - } - if (start_upcall_thread(handle_krb5_upcall, info)) - free_upcall_info(info); + handle_krb5_upcall(clp); } static struct clnt_info * diff --git a/utils/gssd/gssd.h b/utils/gssd/gssd.h index 1e8c58d4..6d53647e 100644 --- a/utils/gssd/gssd.h +++ b/utils/gssd/gssd.h @@ -84,14 +84,17 @@ struct clnt_info { struct clnt_upcall_info { struct clnt_info *clp; - char lbuf[RPC_CHAN_BUF_SIZE]; - int lbuflen; uid_t uid; + int fd; + char *srchost; + char *target; + char *service; }; -void handle_krb5_upcall(struct clnt_upcall_info *clp); -void handle_gssd_upcall(struct clnt_upcall_info *clp); +void handle_krb5_upcall(struct clnt_info *clp); +void handle_gssd_upcall(struct clnt_info *clp); void free_upcall_info(struct clnt_upcall_info *info); +void gssd_free_client(struct clnt_info *clp); #endif /* _RPC_GSSD_H_ */ diff --git a/utils/gssd/gssd_proc.c b/utils/gssd/gssd_proc.c index e830f497..ebec414e 100644 --- a/utils/gssd/gssd_proc.c +++ b/utils/gssd/gssd_proc.c @@ -80,6 +80,8 @@ #include "nfslib.h" #include "gss_names.h" +extern pthread_mutex_t clp_lock; + /* Encryption types supported by the kernel rpcsec_gss code */ int num_krb5_enctypes = 0; krb5_enctype *krb5_enctypes = NULL; @@ -723,22 +725,133 @@ out_return_error: goto out; } -void -handle_krb5_upcall(struct clnt_upcall_info *info) +static struct clnt_upcall_info * +alloc_upcall_info(struct clnt_info *clp, uid_t uid, int fd, char *srchost, + char *target, char *service) { - struct clnt_info *clp = info->clp; + struct clnt_upcall_info *info; + + info = malloc(sizeof(struct clnt_upcall_info)); + if (info == NULL) + return NULL; + + memset(info, 0, sizeof(*info)); + pthread_mutex_lock(&clp_lock); + clp->refcount++; + pthread_mutex_unlock(&clp_lock); + info->clp = clp; + info->uid = uid; + info->fd = fd; + if (srchost) { + info->srchost = strdup(srchost); + if (info->srchost == NULL) + goto out_info; + } + if (target) { + info->target = strdup(target); + if (info->target == NULL) + goto out_srchost; + } + if (service) { + info->service = strdup(service); + if (info->service == NULL) + goto out_target; + } + +out: + return info; + +out_target: + if (info->target) + free(info->target); +out_srchost: + if (info->srchost) + free(info->srchost); +out_info: + free(info); + info = NULL; + goto out; +} - printerr(2, "\n%s: uid %d (%s)\n", __func__, info->uid, clp->relpath); +void free_upcall_info(struct clnt_upcall_info *info) +{ + gssd_free_client(info->clp); + if (info->service) + free(info->service); + if (info->target) + free(info->target); + if (info->srchost) + free(info->srchost); + free(info); +} - process_krb5_upcall(clp, info->uid, clp->krb5_fd, NULL, NULL, NULL); +static void +gssd_work_thread_fn(struct clnt_upcall_info *info) +{ + process_krb5_upcall(info->clp, info->uid, info->fd, info->srchost, info->target, info->service); free_upcall_info(info); } +static int +start_upcall_thread(void (*func)(struct clnt_upcall_info *), void *info) +{ + pthread_attr_t attr; + pthread_t th; + int ret; + + ret = pthread_attr_init(&attr); + if (ret != 0) { + printerr(0, "ERROR: failed to init pthread attr: ret %d: %s\n", + ret, strerror(errno)); + return ret; + } + ret = pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED); + if (ret != 0) { + printerr(0, "ERROR: failed to create pthread attr: ret %d: " + "%s\n", ret, strerror(errno)); + return ret; + } + + ret = pthread_create(&th, &attr, (void *)func, (void *)info); + if (ret != 0) + printerr(0, "ERROR: pthread_create failed: ret %d: %s\n", + ret, strerror(errno)); + return ret; +} + +void +handle_krb5_upcall(struct clnt_info *clp) +{ + uid_t uid; + struct clnt_upcall_info *info; + int err; + + if (read(clp->krb5_fd, &uid, sizeof(uid)) < (ssize_t)sizeof(uid)) { + printerr(0, "WARNING: failed reading uid from krb5 " + "upcall pipe: %s\n", strerror(errno)); + return; + } + printerr(2, "\n%s: uid %d (%s)\n", __func__, uid, clp->relpath); + + info = alloc_upcall_info(clp, uid, clp->krb5_fd, NULL, NULL, NULL); + if (info == NULL) { + printerr(0, "%s: failed to allocate clnt_upcall_info\n", __func__); + do_error_downcall(clp->krb5_fd, uid, -EACCES); + return; + } + err = start_upcall_thread(gssd_work_thread_fn, info); + if (err != 0) { + do_error_downcall(clp->krb5_fd, uid, -EACCES); + free_upcall_info(info); + } +} + void -handle_gssd_upcall(struct clnt_upcall_info *info) +handle_gssd_upcall(struct clnt_info *clp) { - struct clnt_info *clp = info->clp; uid_t uid; + char lbuf[RPC_CHAN_BUF_SIZE]; + int lbuflen = 0; char *p; char *mech = NULL; char *uidstr = NULL; @@ -746,20 +859,22 @@ handle_gssd_upcall(struct clnt_upcall_info *info) char *service = NULL; char *srchost = NULL; char *enctypes = NULL; - char *upcall_str; - char *pbuf = info->lbuf; pthread_t tid = pthread_self(); + struct clnt_upcall_info *info; + int err; - printerr(2, "\n%s(0x%x): '%s' (%s)\n", __func__, tid, - info->lbuf, clp->relpath); - - upcall_str = strdup(info->lbuf); - if (upcall_str == NULL) { - printerr(0, "ERROR: malloc failure\n"); - goto out_nomem; + lbuflen = read(clp->gssd_fd, lbuf, sizeof(lbuf)); + if (lbuflen <= 0 || lbuf[lbuflen-1] != '\n') { + printerr(0, "WARNING: handle_gssd_upcall: " + "failed reading request\n"); + return; } + lbuf[lbuflen-1] = 0; + + printerr(2, "\n%s(0x%x): '%s' (%s)\n", __func__, tid, + lbuf, clp->relpath); - while ((p = strsep(&pbuf, " "))) { + for (p = strtok(lbuf, " "); p; p = strtok(NULL, " ")) { if (!strncmp(p, "mech=", strlen("mech="))) mech = p + strlen("mech="); else if (!strncmp(p, "uid=", strlen("uid="))) @@ -777,8 +892,8 @@ handle_gssd_upcall(struct clnt_upcall_info *info) if (!mech || strlen(mech) < 1) { printerr(0, "WARNING: handle_gssd_upcall: " "failed to find gss mechanism name " - "in upcall string '%s'\n", upcall_str); - goto out; + "in upcall string '%s'\n", lbuf); + return; } if (uidstr) { @@ -790,21 +905,21 @@ handle_gssd_upcall(struct clnt_upcall_info *info) if (!uidstr) { printerr(0, "WARNING: handle_gssd_upcall: " "failed to find uid " - "in upcall string '%s'\n", upcall_str); - goto out; + "in upcall string '%s'\n", lbuf); + return; } if (enctypes && parse_enctypes(enctypes) != 0) { printerr(0, "WARNING: handle_gssd_upcall: " "parsing encryption types failed: errno %d\n", errno); - goto out; + return; } if (target && strlen(target) < 1) { printerr(0, "WARNING: handle_gssd_upcall: " "failed to parse target name " - "in upcall string '%s'\n", upcall_str); - goto out; + "in upcall string '%s'\n", lbuf); + return; } /* @@ -818,21 +933,26 @@ handle_gssd_upcall(struct clnt_upcall_info *info) if (service && strlen(service) < 1) { printerr(0, "WARNING: handle_gssd_upcall: " "failed to parse service type " - "in upcall string '%s'\n", upcall_str); - goto out; + "in upcall string '%s'\n", lbuf); + return; } - if (strcmp(mech, "krb5") == 0 && clp->servername) - process_krb5_upcall(clp, uid, clp->gssd_fd, srchost, target, service); - else { + if (strcmp(mech, "krb5") == 0 && clp->servername) { + info = alloc_upcall_info(clp, uid, clp->gssd_fd, srchost, target, service); + if (info == NULL) { + printerr(0, "%s: failed to allocate clnt_upcall_info\n", __func__); + do_error_downcall(clp->gssd_fd, uid, -EACCES); + return; + } + err = start_upcall_thread(gssd_work_thread_fn, info); + if (err != 0) { + do_error_downcall(clp->gssd_fd, uid, -EACCES); + free_upcall_info(info); + } + } else { if (clp->servername) printerr(0, "WARNING: handle_gssd_upcall: " "received unknown gss mech '%s'\n", mech); do_error_downcall(clp->gssd_fd, uid, -EACCES); } -out: - free(upcall_str); -out_nomem: - free_upcall_info(info); - return; }