6a3fd92e73
Make eCryptfs key module subsystem respect namespaces. Since I will be removing the netlink interface in a future patch, I just made changes to the netlink.c code so that it will not break the build. With my recent patches, the kernel module currently defaults to the device handle interface rather than the netlink interface. [akpm@linux-foundation.org: export free_user_ns()] Signed-off-by: Michael Halcrow <mhalcrow@us.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
78 lines
1.6 KiB
C
78 lines
1.6 KiB
C
/*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation, version 2 of the
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* License.
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*/
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#include <linux/module.h>
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#include <linux/version.h>
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#include <linux/nsproxy.h>
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#include <linux/slab.h>
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#include <linux/user_namespace.h>
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/*
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* Clone a new ns copying an original user ns, setting refcount to 1
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* @old_ns: namespace to clone
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* Return NULL on error (failure to kmalloc), new ns otherwise
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*/
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static struct user_namespace *clone_user_ns(struct user_namespace *old_ns)
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{
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struct user_namespace *ns;
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struct user_struct *new_user;
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int n;
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ns = kmalloc(sizeof(struct user_namespace), GFP_KERNEL);
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if (!ns)
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return ERR_PTR(-ENOMEM);
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kref_init(&ns->kref);
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for (n = 0; n < UIDHASH_SZ; ++n)
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INIT_HLIST_HEAD(ns->uidhash_table + n);
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/* Insert new root user. */
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ns->root_user = alloc_uid(ns, 0);
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if (!ns->root_user) {
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kfree(ns);
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return ERR_PTR(-ENOMEM);
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}
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/* Reset current->user with a new one */
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new_user = alloc_uid(ns, current->uid);
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if (!new_user) {
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free_uid(ns->root_user);
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kfree(ns);
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return ERR_PTR(-ENOMEM);
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}
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switch_uid(new_user);
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return ns;
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}
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struct user_namespace * copy_user_ns(int flags, struct user_namespace *old_ns)
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{
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struct user_namespace *new_ns;
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BUG_ON(!old_ns);
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get_user_ns(old_ns);
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if (!(flags & CLONE_NEWUSER))
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return old_ns;
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new_ns = clone_user_ns(old_ns);
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put_user_ns(old_ns);
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return new_ns;
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}
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void free_user_ns(struct kref *kref)
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{
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struct user_namespace *ns;
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ns = container_of(kref, struct user_namespace, kref);
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release_uids(ns);
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kfree(ns);
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}
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EXPORT_SYMBOL(free_user_ns);
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