057f6c019f
Prevent permission checking from being performed when the kernel wants to unconditionally remove a sysfs group, by introducing an kernel-only variant of lookup_one_len(), lookup_one_len_kern(). Additionally, as sysfs_remove_group() does not check the return value of the lookup before using it, a BUG_ON has been added to pinpoint the cause of any problems potentially caused by this (and as a form of annotation). Signed-off-by: James Morris <jmorris@namei.org> Cc: Nagendra Singh Tomar <nagendra_tomar@adaptec.com> Cc: Tejun Heo <htejun@gmail.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
91 lines
1.8 KiB
C
91 lines
1.8 KiB
C
/*
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* fs/sysfs/group.c - Operations for adding/removing multiple files at once.
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*
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* Copyright (c) 2003 Patrick Mochel
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* Copyright (c) 2003 Open Source Development Lab
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*
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* This file is released undert the GPL v2.
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*
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*/
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#include <linux/kobject.h>
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#include <linux/module.h>
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#include <linux/dcache.h>
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#include <linux/namei.h>
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#include <linux/err.h>
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#include <linux/fs.h>
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#include <asm/semaphore.h>
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#include "sysfs.h"
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static void remove_files(struct dentry * dir,
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const struct attribute_group * grp)
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{
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struct attribute *const* attr;
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for (attr = grp->attrs; *attr; attr++)
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sysfs_hash_and_remove(dir,(*attr)->name);
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}
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static int create_files(struct dentry * dir,
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const struct attribute_group * grp)
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{
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struct attribute *const* attr;
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int error = 0;
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for (attr = grp->attrs; *attr && !error; attr++) {
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error = sysfs_add_file(dir, *attr, SYSFS_KOBJ_ATTR);
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}
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if (error)
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remove_files(dir,grp);
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return error;
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}
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int sysfs_create_group(struct kobject * kobj,
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const struct attribute_group * grp)
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{
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struct dentry * dir;
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int error;
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BUG_ON(!kobj || !kobj->dentry);
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if (grp->name) {
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error = sysfs_create_subdir(kobj,grp->name,&dir);
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if (error)
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return error;
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} else
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dir = kobj->dentry;
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dir = dget(dir);
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if ((error = create_files(dir,grp))) {
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if (grp->name)
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sysfs_remove_subdir(dir);
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}
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dput(dir);
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return error;
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}
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void sysfs_remove_group(struct kobject * kobj,
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const struct attribute_group * grp)
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{
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struct dentry * dir;
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if (grp->name) {
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dir = lookup_one_len_kern(grp->name, kobj->dentry,
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strlen(grp->name));
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BUG_ON(IS_ERR(dir));
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}
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else
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dir = dget(kobj->dentry);
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remove_files(dir,grp);
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if (grp->name)
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sysfs_remove_subdir(dir);
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/* release the ref. taken in this routine */
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dput(dir);
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}
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EXPORT_SYMBOL_GPL(sysfs_create_group);
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EXPORT_SYMBOL_GPL(sysfs_remove_group);
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