[PATCH v3] Add security.* XATTR support for the UBIFS
Mimi Zohar
zohar at linux.vnet.ibm.com
Wed Apr 11 19:27:33 EDT 2012
On Wed, 2012-04-11 at 14:28 -0700, subodh.nijsure at gmail.com wrote:
> From: Subodh Nijsure <snijsure at grid-net.com>
>
> Also fix couple of bugs in UBIFS extended attribute length calculation.
>
> Changes in v3:
> Invoke ubifs_init_security only if CONFIG_UBIFS_FS_XATTR is defined.
> Invoke it before d_instantiate and check ubifs_init_security return
> code.
> Changes in v2:
> Instead of just handling security.selinux extended attribute handle
> all security.* attributes.
>
> TESTING: Tested on MX28 based platforms using Micron MT29F2G08ABAEAH4 NAND
> With these change we are able to label UBIFS filesystem with
> security.selinux and run system with selinux enabled.
> This change also allows one to set other security.* extended
> attributes, such as security.smack security.evm, security.ima
> Ran integck test on UBI filesystem.
>
> Signed-off-by: Subodh Nijsure <snijsure at grid-net.com>
> ---
> fs/ubifs/dir.c | 47 +++++++++++++++++
> fs/ubifs/file.c | 6 ++
> fs/ubifs/journal.c | 12 +++-
> fs/ubifs/super.c | 3 +
> fs/ubifs/ubifs.h | 9 +++
> fs/ubifs/xattr.c | 147 ++++++++++++++++++++++++++++++++++++++++++++++++----
> 6 files changed, 210 insertions(+), 14 deletions(-)
>
> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
> index ec9f187..422bcec 100644
> --- a/fs/ubifs/dir.c
> +++ b/fs/ubifs/dir.c
> @@ -292,6 +292,18 @@ static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
>
> ubifs_release_budget(c, &req);
> insert_inode_hash(inode);
> +
> +#ifdef CONFIG_UBIFS_FS_XATTR
> +
> + err = ubifs_init_security(dir, inode, &dentry->d_name);
> + if (err) {
> + ubifs_err("cannot initialize extended attribute, error %d",
> + err);
> + goto out_cancel;
> + }
> +
> +#endif
> +
The preferred method for including code based on CONFIG options is to
define a stub function in an include file. #ifdef's in C code is
frowned upon (refer to section 2.2 of Documentation/SubmittingPatches).
thanks,
Mimi
> d_instantiate(dentry, inode);
> return 0;
>
> @@ -753,6 +765,17 @@ static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
> mutex_unlock(&dir_ui->ui_mutex);
>
> ubifs_release_budget(c, &req);
> +
> +#ifdef CONFIG_UBIFS_FS_XATTR
> +
> + err = ubifs_init_security(dir, inode, &dentry->d_name);
> + if (err) {
> + ubifs_err("cannot initialize extended attribute, error %d",
> + err);
> + goto out_cancel;
> + }
> +
> +#endif
> d_instantiate(dentry, inode);
> return 0;
>
> @@ -830,6 +853,18 @@ static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
>
> ubifs_release_budget(c, &req);
> insert_inode_hash(inode);
> +
> +#ifdef CONFIG_UBIFS_FS_XATTR
> +
> + err = ubifs_init_security(dir, inode, &dentry->d_name);
> + if (err) {
> + ubifs_err("cannot initialize extended attribute, error %d",
> + err);
> + goto out_cancel;
> + }
> +
> +#endif
> +
> d_instantiate(dentry, inode);
> return 0;
>
> @@ -906,6 +941,18 @@ static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
>
> ubifs_release_budget(c, &req);
> insert_inode_hash(inode);
> +
> +#ifdef CONFIG_UBIFS_FS_XATTR
> +
> + err = ubifs_init_security(dir, inode, &dentry->d_name);
> + if (err) {
> + ubifs_err("cannot initialize extended attribute, error %d",
> + err);
> + goto out_cancel;
> + }
> +
> +#endif
> +
> d_instantiate(dentry, inode);
> return 0;
>
> diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
> index 5c8f6dc..b8e9d66 100644
> --- a/fs/ubifs/file.c
> +++ b/fs/ubifs/file.c
> @@ -1575,6 +1575,12 @@ const struct inode_operations ubifs_symlink_inode_operations = {
> .follow_link = ubifs_follow_link,
> .setattr = ubifs_setattr,
> .getattr = ubifs_getattr,
> +#ifdef CONFIG_UBIFS_FS_XATTR
> + .setxattr = ubifs_symlink_setxattr,
> + .getxattr = ubifs_symlink_getxattr,
> + .listxattr = ubifs_listxattr,
> + .removexattr = ubifs_removexattr,
> +#endif
> };
>
> const struct file_operations ubifs_file_operations = {
> diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
> index 2f438ab..725dc17 100644
> --- a/fs/ubifs/journal.c
> +++ b/fs/ubifs/journal.c
> @@ -553,7 +553,8 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir,
>
> dbg_jnl("ino %lu, dent '%.*s', data len %d in dir ino %lu",
> inode->i_ino, nm->len, nm->name, ui->data_len, dir->i_ino);
> - ubifs_assert(dir_ui->data_len == 0);
> + if (!xent)
> + ubifs_assert(dir_ui->data_len == 0);
> ubifs_assert(mutex_is_locked(&dir_ui->ui_mutex));
>
> dlen = UBIFS_DENT_NODE_SZ + nm->len + 1;
> @@ -572,7 +573,11 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir,
>
> aligned_dlen = ALIGN(dlen, 8);
> aligned_ilen = ALIGN(ilen, 8);
> - len = aligned_dlen + aligned_ilen + UBIFS_INO_NODE_SZ;
> + /* Make sure to account for dir_ui+data_len in length calculation
> + * in case there is extended attribute.
> + */
> + len = aligned_dlen + aligned_ilen +
> + UBIFS_INO_NODE_SZ + dir_ui->data_len;
> dent = kmalloc(len, GFP_NOFS);
> if (!dent)
> return -ENOMEM;
> @@ -649,7 +654,8 @@ int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir,
>
> ino_key_init(c, &ino_key, dir->i_ino);
> ino_offs += aligned_ilen;
> - err = ubifs_tnc_add(c, &ino_key, lnum, ino_offs, UBIFS_INO_NODE_SZ);
> + err = ubifs_tnc_add(c, &ino_key, lnum, ino_offs,
> + UBIFS_INO_NODE_SZ + dir_ui->data_len);
> if (err)
> goto out_ro;
>
> diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
> index 76e4e05..c28ac04 100644
> --- a/fs/ubifs/super.c
> +++ b/fs/ubifs/super.c
> @@ -2061,6 +2061,9 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
> if (c->max_inode_sz > MAX_LFS_FILESIZE)
> sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
> sb->s_op = &ubifs_super_operations;
> +#ifdef CONFIG_UBIFS_FS_XATTR
> + sb->s_xattr = ubifs_xattr_handlers;
> +#endif
>
> mutex_lock(&c->umount_mutex);
> err = mount_ubifs(c);
> diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h
> index 93d59ac..60b57f7 100644
> --- a/fs/ubifs/ubifs.h
> +++ b/fs/ubifs/ubifs.h
> @@ -36,6 +36,7 @@
> #include <linux/mtd/ubi.h>
> #include <linux/pagemap.h>
> #include <linux/backing-dev.h>
> +#include <linux/security.h>
> #include "ubifs-media.h"
>
> /* Version of this UBIFS implementation */
> @@ -1454,6 +1455,7 @@ extern spinlock_t ubifs_infos_lock;
> extern atomic_long_t ubifs_clean_zn_cnt;
> extern struct kmem_cache *ubifs_inode_slab;
> extern const struct super_operations ubifs_super_operations;
> +extern const struct xattr_handler *ubifs_xattr_handlers[];
> extern const struct address_space_operations ubifs_file_address_operations;
> extern const struct file_operations ubifs_file_operations;
> extern const struct inode_operations ubifs_file_inode_operations;
> @@ -1736,10 +1738,17 @@ int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
> struct kstat *stat);
>
> /* xattr.c */
> +
> int ubifs_setxattr(struct dentry *dentry, const char *name,
> const void *value, size_t size, int flags);
> +int ubifs_init_security(struct inode *dentry, struct inode *inode,
> + const struct qstr *qstr);
> +int ubifs_symlink_setxattr(struct dentry *dentry, const char *name,
> + const void *value, size_t size, int flags);
> ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf,
> size_t size);
> +ssize_t ubifs_symlink_getxattr(struct dentry *dentry, const char *name,
> + void *buf, size_t size);
> ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size);
> int ubifs_removexattr(struct dentry *dentry, const char *name);
>
> diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
> index 85b2722..c8be7cd 100644
> --- a/fs/ubifs/xattr.c
> +++ b/fs/ubifs/xattr.c
> @@ -209,11 +209,11 @@ static int change_xattr(struct ubifs_info *c, struct inode *host,
> goto out_free;
> }
> inode->i_size = ui->ui_size = size;
> - ui->data_len = size;
>
> mutex_lock(&host_ui->ui_mutex);
> host->i_ctime = ubifs_current_time(host);
> host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
> + ui->data_len = size;
> host_ui->xattr_size += CALC_XATTR_BYTES(size);
>
> /*
> @@ -293,18 +293,16 @@ static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum)
> return ERR_PTR(-EINVAL);
> }
>
> -int ubifs_setxattr(struct dentry *dentry, const char *name,
> - const void *value, size_t size, int flags)
> +static int __ubifs_setxattr(struct inode *host, const char *name,
> + const void *value, size_t size, int flags)
> {
> - struct inode *inode, *host = dentry->d_inode;
> + struct inode *inode;
> struct ubifs_info *c = host->i_sb->s_fs_info;
> struct qstr nm = { .name = name, .len = strlen(name) };
> struct ubifs_dent_node *xent;
> union ubifs_key key;
> int err, type;
>
> - dbg_gen("xattr '%s', host ino %lu ('%.*s'), size %zd", name,
> - host->i_ino, dentry->d_name.len, dentry->d_name.name, size);
> ubifs_assert(mutex_is_locked(&host->i_mutex));
>
> if (size > UBIFS_MAX_INO_DATA)
> @@ -356,10 +354,29 @@ out_free:
> return err;
> }
>
> -ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf,
> - size_t size)
> +int ubifs_symlink_setxattr(struct dentry *dentry, const char *name,
> + const void *value, size_t size, int flags)
> {
> - struct inode *inode, *host = dentry->d_inode;
> + struct inode *host = dentry->d_inode;
> + dbg_gen("xattr '%s', host ino %lu ('%.*s'), size %zd", name,
> + host->i_ino, dentry->d_name.len, dentry->d_name.name, size);
> + return __ubifs_setxattr(host, name, value, size, flags);
> +}
> +
> +int ubifs_setxattr(struct dentry *dentry, const char *name,
> + const void *value, size_t size, int flags)
> +{
> + struct inode *host = dentry->d_inode;
> + dbg_gen("xattr '%s', host ino %lu ('%.*s'), size %zd", name,
> + host->i_ino, dentry->d_name.len, dentry->d_name.name, size);
> + return __ubifs_setxattr(host, name, value, size, flags);
> +}
> +
> +static
> +ssize_t __ubifs_getxattr(struct inode *host, const char *name, void *buf,
> + size_t size)
> +{
> + struct inode *inode;
> struct ubifs_info *c = host->i_sb->s_fs_info;
> struct qstr nm = { .name = name, .len = strlen(name) };
> struct ubifs_inode *ui;
> @@ -367,8 +384,8 @@ ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf,
> union ubifs_key key;
> int err;
>
> - dbg_gen("xattr '%s', ino %lu ('%.*s'), buf size %zd", name,
> - host->i_ino, dentry->d_name.len, dentry->d_name.name, size);
> + dbg_gen("xattr '%s', ino %lu buf size %zd", name,
> + host->i_ino, size);
>
> err = check_namespace(&nm);
> if (err < 0)
> @@ -416,6 +433,25 @@ out_unlock:
> return err;
> }
>
> +ssize_t ubifs_symlink_getxattr(struct dentry *dentry, const char *name,
> + void *buf, size_t size)
> +{
> + struct inode *host = dentry->d_inode;
> + dbg_gen("xattr '%s', ino %lu ('%.*s'), buf size %zd", name,
> + host->i_ino, dentry->d_name.len, dentry->d_name.name, size);
> + return __ubifs_getxattr(host, name, buf, size);
> +}
> +
> +ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf,
> + size_t size)
> +{
> + struct inode *host = dentry->d_inode;
> + dbg_gen("xattr '%s', ino %lu ('%.*s'), buf size %zd", name,
> + host->i_ino, dentry->d_name.len, dentry->d_name.name, size);
> + return __ubifs_getxattr(host, name, buf, size);
> +}
> +
> +
> ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size)
> {
> union ubifs_key key;
> @@ -568,3 +604,92 @@ out_free:
> kfree(xent);
> return err;
> }
> +
> +size_t
> +ubifs_security_listxattr(struct dentry *d, char *list, size_t list_size,
> + const char *name, size_t name_len, int flags)
> +{
> + const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
> + const size_t total_len = prefix_len + name_len + 1;
> + if (list && total_len <= list_size) {
> + memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
> + memcpy(list+prefix_len, name, name_len);
> + list[prefix_len + name_len] = '\0';
> + }
> + return total_len;
> +}
> +
> +
> +int ubifs_security_getxattr(struct dentry *d, const char *name,
> + void *buffer, size_t size, int flags)
> +{
> + if (strcmp(name, "") == 0)
> + return -EINVAL;
> + return __ubifs_getxattr(d->d_inode, name, buffer, size);
> +}
> +
> +
> +int ubifs_security_setxattr(struct dentry *d, const char *name,
> + const void *value, size_t size,
> + int flags, int handler_flags)
> +{
> + if (strcmp(name, "") == 0)
> + return -EINVAL;
> + return __ubifs_setxattr(d->d_inode, name, value,
> + size, flags);
> +}
> +
> +struct xattr_handler ubifs_xattr_security_handler = {
> + .prefix = XATTR_SECURITY_PREFIX,
> + .list = ubifs_security_listxattr,
> + .get = ubifs_security_getxattr,
> + .set = ubifs_security_setxattr,
> +};
> +
> +const struct xattr_handler *ubifs_xattr_handlers[] = {
> + &ubifs_xattr_security_handler,
> + NULL
> +};
> +
> +static int ubifs_initxattrs(struct inode *inode,
> + const struct xattr *xattr_array, void *fs_info)
> +{
> + const struct xattr *xattr;
> + char *name;
> + int err = 0;
> +
> + for (xattr = xattr_array; xattr->name != NULL; xattr++) {
> + name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
> + strlen(xattr->name) + 1, GFP_NOFS);
> + if (!name) {
> + err = -ENOMEM;
> + break;
> + }
> + strcpy(name, XATTR_SECURITY_PREFIX);
> + strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
> +
> + err = __ubifs_setxattr(inode, xattr->name, xattr->value,
> + xattr->value_len, 0);
> + kfree(name);
> + if (err < 0)
> + break;
> + }
> + return err;
> +}
> +
> +int
> +ubifs_init_security(struct inode *dentry, struct inode *inode,
> + const struct qstr *qstr)
> +{
> + struct ubifs_inode *dir_ui = ubifs_inode(inode);
> + int err = 0;
> +
> + mutex_lock(&dir_ui->ui_mutex);
> + mutex_lock(&inode->i_mutex);
> +
> + err = security_inode_init_security(inode, dentry, qstr,
> + &ubifs_initxattrs, 0);
> + mutex_unlock(&inode->i_mutex);
> + mutex_unlock(&dir_ui->ui_mutex);
> + return err;
> +}
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