Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756249Ab1BXPCQ (ORCPT ); Thu, 24 Feb 2011 10:02:16 -0500 Received: from 184-106-158-135.static.cloud-ips.com ([184.106.158.135]:40129 "EHLO mail" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756231Ab1BXPCO (ORCPT ); Thu, 24 Feb 2011 10:02:14 -0500 Date: Thu, 24 Feb 2011 15:02:29 +0000 From: "Serge E. Hallyn" To: "Serge E. Hallyn" Cc: Andrew Morton , containers@lists.linux-foundation.org, kernel list , "Eric W. Biederman" , Michael Kerrisk , dhowells@redhat.com, oleg@mail.hallyn.com, dlezcano@mail.hallyn.com, LSM Subject: [PATCH 03/10] allow sethostname in a container Message-ID: <20110224150229.GC8262@mail.hallyn.com> References: <20110224150150.GA8262@mail.hallyn.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110224150150.GA8262@mail.hallyn.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4380 Lines: 133 Changelog: Feb 23: let clone_uts_ns() handle setting uts->user_ns To do so we need to pass in the task_struct who'll get the utsname, so we can get its user_ns. Feb 23: As per Oleg's coment, just pass in tsk, instead of two of its members. Signed-off-by: Serge E. Hallyn Acked-by: "Eric W. Biederman" Acked-by: Daniel Lezcano --- include/linux/utsname.h | 6 +++--- kernel/nsproxy.c | 7 +------ kernel/sys.c | 2 +- kernel/utsname.c | 12 +++++++----- 4 files changed, 12 insertions(+), 15 deletions(-) diff --git a/include/linux/utsname.h b/include/linux/utsname.h index 2c3c0f5..4e5b021 100644 --- a/include/linux/utsname.h +++ b/include/linux/utsname.h @@ -54,7 +54,7 @@ static inline void get_uts_ns(struct uts_namespace *ns) } extern struct uts_namespace *copy_utsname(unsigned long flags, - struct uts_namespace *ns); + struct task_struct *tsk); extern void free_uts_ns(struct kref *kref); static inline void put_uts_ns(struct uts_namespace *ns) @@ -71,12 +71,12 @@ static inline void put_uts_ns(struct uts_namespace *ns) } static inline struct uts_namespace *copy_utsname(unsigned long flags, - struct uts_namespace *ns) + struct task_struct *tsk) { if (flags & CLONE_NEWUTS) return ERR_PTR(-EINVAL); - return ns; + return tsk->nsproxy->uts_ns; } #endif diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index 034dc2e..b97fc9d 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -69,16 +69,11 @@ static struct nsproxy *create_new_namespaces(unsigned long flags, goto out_ns; } - new_nsp->uts_ns = copy_utsname(flags, tsk->nsproxy->uts_ns); + new_nsp->uts_ns = copy_utsname(flags, tsk); if (IS_ERR(new_nsp->uts_ns)) { err = PTR_ERR(new_nsp->uts_ns); goto out_uts; } - if (new_nsp->uts_ns != tsk->nsproxy->uts_ns) { - put_user_ns(new_nsp->uts_ns->user_ns); - new_nsp->uts_ns->user_ns = task_cred_xxx(tsk, user)->user_ns; - get_user_ns(new_nsp->uts_ns->user_ns); - } new_nsp->ipc_ns = copy_ipcs(flags, tsk->nsproxy->ipc_ns); if (IS_ERR(new_nsp->ipc_ns)) { diff --git a/kernel/sys.c b/kernel/sys.c index 18da702..7a1bbad 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1177,7 +1177,7 @@ SYSCALL_DEFINE2(sethostname, char __user *, name, int, len) int errno; char tmp[__NEW_UTS_LEN]; - if (!capable(CAP_SYS_ADMIN)) + if (!ns_capable(current->nsproxy->uts_ns->user_ns, CAP_SYS_ADMIN)) return -EPERM; if (len < 0 || len > __NEW_UTS_LEN) return -EINVAL; diff --git a/kernel/utsname.c b/kernel/utsname.c index a7b3a8d..4464617 100644 --- a/kernel/utsname.c +++ b/kernel/utsname.c @@ -31,7 +31,8 @@ static struct uts_namespace *create_uts_ns(void) * @old_ns: namespace to clone * Return NULL on error (failure to kmalloc), new ns otherwise */ -static struct uts_namespace *clone_uts_ns(struct uts_namespace *old_ns) +static struct uts_namespace *clone_uts_ns(struct task_struct *tsk, + struct uts_namespace *old_ns) { struct uts_namespace *ns; @@ -41,8 +42,7 @@ static struct uts_namespace *clone_uts_ns(struct uts_namespace *old_ns) down_read(&uts_sem); memcpy(&ns->name, &old_ns->name, sizeof(ns->name)); - ns->user_ns = old_ns->user_ns; - get_user_ns(ns->user_ns); + ns->user_ns = get_user_ns(task_cred_xxx(tsk, user)->user_ns); up_read(&uts_sem); return ns; } @@ -53,8 +53,10 @@ static struct uts_namespace *clone_uts_ns(struct uts_namespace *old_ns) * utsname of this process won't be seen by parent, and vice * versa. */ -struct uts_namespace *copy_utsname(unsigned long flags, struct uts_namespace *old_ns) +struct uts_namespace *copy_utsname(unsigned long flags, + struct task_struct *tsk) { + struct uts_namespace *old_ns = tsk->nsproxy->uts_ns; struct uts_namespace *new_ns; BUG_ON(!old_ns); @@ -63,7 +65,7 @@ struct uts_namespace *copy_utsname(unsigned long flags, struct uts_namespace *ol if (!(flags & CLONE_NEWUTS)) return old_ns; - new_ns = clone_uts_ns(old_ns); + new_ns = clone_uts_ns(tsk, old_ns); put_uts_ns(old_ns); return new_ns; -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/