From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756013Ab2DHFVJ (ORCPT ); Sun, 8 Apr 2012 01:21:09 -0400 Received: from out08.mta.xmission.com ([166.70.13.238]:56911 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752609Ab2DHFMT (ORCPT ); Sun, 8 Apr 2012 01:12:19 -0400 From: "\"Eric W. Beiderman" To: Cc: , , Linux Containers , Andrew Morton , Linus Torvalds , Al Viro , Cyrill Gorcunov , "Eric W. Biederman" Date: Sat, 7 Apr 2012 22:15:03 -0700 Message-Id: <1333862139-31737-7-git-send-email-ebiederm@xmission.com> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: References: X-XM-SPF: eid=;;;mid=;;;hst=in02.mta.xmission.com;;;ip=98.207.153.68;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX190gwjdoOA0P/Gjsb8cJu+CgZmYkoeWln0= X-SA-Exim-Connect-IP: 98.207.153.68 X-SA-Exim-Mail-From: ebiederm@xmission.com X-Spam-Report: * 1.1 FH_FROMEML_NOTLD E-mail address doesn't have TLD (.com, etc.) * 1.5 XMNoVowels Alpha-numberic number with no vowels * 0.1 XMSubLong Long Subject * 0.0 T_TM2_M_HEADER_IN_MSG BODY: T_TM2_M_HEADER_IN_MSG * -0.0 BAYES_20 BODY: Bayes spam probability is 5 to 20% * [score: 0.1529] * -0.0 DCC_CHECK_NEGATIVE Not listed in DCC * [sa02 1397; Body=1 Fuz1=1 Fuz2=1] * 0.0 T_TooManySym_01 4+ unique symbols in subject * 0.0 T_TooManySym_02 5+ unique symbols in subject * 0.0 T_XMDrugObfuBody_04 obfuscated drug references * 0.4 UNTRUSTED_Relay Comes from a non-trusted relay X-Spam-DCC: XMission; sa02 1397; Body=1 Fuz1=1 Fuz2=1 X-Spam-Combo: ***; X-Spam-Relay-Country: ** Subject: [PATCH 07/43] cred: Refcount the user_ns pointed to by the cred. X-Spam-Flag: No X-SA-Exim-Version: 4.2.1 (built Fri, 06 Aug 2010 16:31:04 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Eric W. Biederman struct user_struct will shortly loose it's user_ns reference so make the cred user_ns reference a proper reference complete with reference counting. Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman --- include/linux/cred.h | 2 +- kernel/cred.c | 8 +++----- kernel/user_namespace.c | 8 +++++--- security/keys/process_keys.c | 2 +- 4 files changed, 10 insertions(+), 10 deletions(-) diff --git a/include/linux/cred.h b/include/linux/cred.h index d12c4e4..2c60ec8 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -146,7 +146,7 @@ struct cred { void *security; /* subjective LSM security */ #endif struct user_struct *user; /* real user ID subscription */ - struct user_namespace *user_ns; /* cached user->user_ns */ + struct user_namespace *user_ns; /* user_ns the caps and keyrings are relative to. */ struct group_info *group_info; /* supplementary groups for euid/fsgid */ struct rcu_head rcu; /* RCU deletion hook */ }; diff --git a/kernel/cred.c b/kernel/cred.c index 97b36ee..7a0d806 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -148,6 +148,7 @@ static void put_cred_rcu(struct rcu_head *rcu) if (cred->group_info) put_group_info(cred->group_info); free_uid(cred->user); + put_user_ns(cred->user_ns); kmem_cache_free(cred_jar, cred); } @@ -303,6 +304,7 @@ struct cred *prepare_creds(void) set_cred_subscribers(new, 0); get_group_info(new->group_info); get_uid(new->user); + get_user_ns(new->user_ns); #ifdef CONFIG_KEYS key_get(new->thread_keyring); @@ -412,11 +414,6 @@ int copy_creds(struct task_struct *p, unsigned long clone_flags) goto error_put; } - /* cache user_ns in cred. Doesn't need a refcount because it will - * stay pinned by cred->user - */ - new->user_ns = new->user->user_ns; - #ifdef CONFIG_KEYS /* new threads get their own thread keyrings if their parent already * had one */ @@ -676,6 +673,7 @@ struct cred *prepare_kernel_cred(struct task_struct *daemon) atomic_set(&new->usage, 1); set_cred_subscribers(new, 0); get_uid(new->user); + get_user_ns(new->user_ns); get_group_info(new->group_info); #ifdef CONFIG_KEYS diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c index f084083..58bb878 100644 --- a/kernel/user_namespace.c +++ b/kernel/user_namespace.c @@ -24,7 +24,7 @@ static struct kmem_cache *user_ns_cachep __read_mostly; */ int create_user_ns(struct cred *new) { - struct user_namespace *ns; + struct user_namespace *ns, *parent_ns = new->user_ns; struct user_struct *root_user; int n; @@ -57,8 +57,10 @@ int create_user_ns(struct cred *new) #endif /* tgcred will be cleared in our caller bc CLONE_THREAD won't be set */ - /* root_user holds a reference to ns, our reference can be dropped */ - put_user_ns(ns); + /* Leave the reference to our user_ns with the new cred */ + new->user_ns = ns; + + put_user_ns(parent_ns); return 0; } diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c index 70febff..447fb76 100644 --- a/security/keys/process_keys.c +++ b/security/keys/process_keys.c @@ -858,7 +858,7 @@ void key_replace_session_keyring(void) new-> sgid = old-> sgid; new->fsgid = old->fsgid; new->user = get_uid(old->user); - new->user_ns = new->user_ns; + new->user_ns = get_user_ns(new->user_ns); new->group_info = get_group_info(old->group_info); new->securebits = old->securebits; -- 1.7.2.5