On Fri, 24 Dec 2010, David Howells wrote:
> Add calls to path-based security hooks into CacheFiles as, unlike inode-based
> security, these aren't implicit in the vfs_mkdir() and similar calls.
Adding fsdevel for further review - cachefiles is essentially part of the
vfs, right ?
>
> Reported-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
> ---
>
> fs/cachefiles/namei.c | 52 +++++++++++++++++++++++++++++++++++++++++--------
> security/security.c | 3 +++
> 2 files changed, 47 insertions(+), 8 deletions(-)
>
> diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c
> index 42c7faf..a0358c2 100644
> --- a/fs/cachefiles/namei.c
> +++ b/fs/cachefiles/namei.c
> @@ -275,6 +275,7 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
> bool preemptive)
> {
> struct dentry *grave, *trap;
> + struct path path, path_to_graveyard;
> char nbuffer[8 + 8 + 1];
> int ret;
>
> @@ -287,10 +288,18 @@ static int cachefiles_bury_object(struct cachefiles_cache *cache,
> /* non-directories can just be unlinked */
> if (!S_ISDIR(rep->d_inode->i_mode)) {
> _debug("unlink stale object");
> - ret = vfs_unlink(dir->d_inode, rep);
>
> - if (preemptive)
> - cachefiles_mark_object_buried(cache, rep);
> + path.mnt = cache->mnt;
> + path.dentry = dir;
> + ret = security_path_unlink(&path, rep);
> + if (ret < 0) {
> + cachefiles_io_error(cache, "Unlink security error");
> + } else {
> + ret = vfs_unlink(dir->d_inode, rep);
> +
> + if (preemptive)
> + cachefiles_mark_object_buried(cache, rep);
> + }
>
> mutex_unlock(&dir->d_inode->i_mutex);
>
> @@ -379,12 +388,23 @@ try_again:
> }
>
> /* attempt the rename */
> - ret = vfs_rename(dir->d_inode, rep, cache->graveyard->d_inode, grave);
> - if (ret != 0 && ret != -ENOMEM)
> - cachefiles_io_error(cache, "Rename failed with error %d", ret);
> + path.mnt = cache->mnt;
> + path.dentry = dir;
> + path_to_graveyard.mnt = cache->mnt;
> + path_to_graveyard.dentry = cache->graveyard;
> + ret = security_path_rename(&path, rep, &path_to_graveyard, grave);
> + if (ret < 0) {
> + cachefiles_io_error(cache, "Rename security error %d", ret);
> + } else {
> + ret = vfs_rename(dir->d_inode, rep,
> + cache->graveyard->d_inode, grave);
> + if (ret != 0 && ret != -ENOMEM)
> + cachefiles_io_error(cache,
> + "Rename failed with error %d", ret);
>
> - if (preemptive)
> - cachefiles_mark_object_buried(cache, rep);
> + if (preemptive)
> + cachefiles_mark_object_buried(cache, rep);
> + }
>
> unlock_rename(cache->graveyard, dir);
> dput(grave);
> @@ -448,6 +468,7 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
> {
> struct cachefiles_cache *cache;
> struct dentry *dir, *next = NULL;
> + struct path path;
> unsigned long start;
> const char *name;
> int ret, nlen;
> @@ -458,6 +479,7 @@ int cachefiles_walk_to_object(struct cachefiles_object *parent,
>
> cache = container_of(parent->fscache.cache,
> struct cachefiles_cache, cache);
> + path.mnt = cache->mnt;
>
> ASSERT(parent->dentry);
> ASSERT(parent->dentry->d_inode);
> @@ -511,6 +533,10 @@ lookup_again:
> if (ret < 0)
> goto create_error;
>
> + path.dentry = dir;
> + ret = security_path_mkdir(&path, next, 0);
> + if (ret < 0)
> + goto create_error;
> start = jiffies;
> ret = vfs_mkdir(dir->d_inode, next, 0);
> cachefiles_hist(cachefiles_mkdir_histogram, start);
> @@ -536,6 +562,10 @@ lookup_again:
> if (ret < 0)
> goto create_error;
>
> + path.dentry = dir;
> + ret = security_path_mknod(&path, next, S_IFREG, 0);
> + if (ret < 0)
> + goto create_error;
> start = jiffies;
> ret = vfs_create(dir->d_inode, next, S_IFREG, NULL);
> cachefiles_hist(cachefiles_create_histogram, start);
> @@ -692,6 +722,7 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
> {
> struct dentry *subdir;
> unsigned long start;
> + struct path path;
> int ret;
>
> _enter(",,%s", dirname);
> @@ -719,6 +750,11 @@ struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache,
>
> _debug("attempt mkdir");
>
> + path.mnt = cache->mnt;
> + path.dentry = dir;
> + ret = security_path_mkdir(&path, subdir, 0700);
> + if (ret < 0)
> + goto mkdir_error;
> ret = vfs_mkdir(dir->d_inode, subdir, 0700);
> if (ret < 0)
> goto mkdir_error;
> diff --git a/security/security.c b/security/security.c
> index 1b798d3..568b98d 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -360,6 +360,7 @@ int security_path_mkdir(struct path *dir, struct dentry *dentry, int mode)
> return 0;
> return security_ops->path_mkdir(dir, dentry, mode);
> }
> +EXPORT_SYMBOL(security_path_mkdir);
>
> int security_path_rmdir(struct path *dir, struct dentry *dentry)
> {
> @@ -374,6 +375,7 @@ int security_path_unlink(struct path *dir, struct dentry *dentry)
> return 0;
> return security_ops->path_unlink(dir, dentry);
> }
> +EXPORT_SYMBOL(security_path_unlink);
>
> int security_path_symlink(struct path *dir, struct dentry *dentry,
> const char *old_name)
> @@ -400,6 +402,7 @@ int security_path_rename(struct path *old_dir, struct dentry *old_dentry,
> return security_ops->path_rename(old_dir, old_dentry, new_dir,
> new_dentry);
> }
> +EXPORT_SYMBOL(security_path_rename);
>
> int security_path_truncate(struct path *path)
> {
>
--
James Morris
<jmorris@xxxxxxxxx>
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