diff options
| -rw-r--r-- | fs/attr.c | 50 | ||||
| -rw-r--r-- | include/linux/fs.h | 2 |
2 files changed, 33 insertions, 19 deletions
diff --git a/fs/attr.c b/fs/attr.c index 87ef39db1c34..473d21b3a86d 100644 --- a/fs/attr.c +++ b/fs/attr.c @@ -249,6 +249,34 @@ void setattr_copy(struct user_namespace *mnt_userns, struct inode *inode, } EXPORT_SYMBOL(setattr_copy); +int may_setattr(struct user_namespace *mnt_userns, struct inode *inode, + unsigned int ia_valid) +{ + int error; + + if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_TIMES_SET)) { + if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) + return -EPERM; + } + + /* + * If utimes(2) and friends are called with times == NULL (or both + * times are UTIME_NOW), then we need to check for write permission + */ + if (ia_valid & ATTR_TOUCH) { + if (IS_IMMUTABLE(inode)) + return -EPERM; + + if (!inode_owner_or_capable(mnt_userns, inode)) { + error = inode_permission(mnt_userns, inode, MAY_WRITE); + if (error) + return error; + } + } + return 0; +} +EXPORT_SYMBOL(may_setattr); + /** * notify_change - modify attributes of a filesytem object * @mnt_userns: user namespace of the mount the inode was found from @@ -290,25 +318,9 @@ int notify_change(struct user_namespace *mnt_userns, struct dentry *dentry, WARN_ON_ONCE(!inode_is_locked(inode)); - if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID | ATTR_TIMES_SET)) { - if (IS_IMMUTABLE(inode) || IS_APPEND(inode)) - return -EPERM; - } - - /* - * If utimes(2) and friends are called with times == NULL (or both - * times are UTIME_NOW), then we need to check for write permission - */ - if (ia_valid & ATTR_TOUCH) { - if (IS_IMMUTABLE(inode)) - return -EPERM; - - if (!inode_owner_or_capable(mnt_userns, inode)) { - error = inode_permission(mnt_userns, inode, MAY_WRITE); - if (error) - return error; - } - } + error = may_setattr(mnt_userns, inode, ia_valid); + if (error) + return error; if ((ia_valid & ATTR_MODE)) { umode_t amode = attr->ia_mode; diff --git a/include/linux/fs.h b/include/linux/fs.h index 640574294216..50192964bf6b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3469,6 +3469,8 @@ extern int buffer_migrate_page_norefs(struct address_space *, #define buffer_migrate_page_norefs NULL #endif +int may_setattr(struct user_namespace *mnt_userns, struct inode *inode, + unsigned int ia_valid); int setattr_prepare(struct user_namespace *, struct dentry *, struct iattr *); extern int inode_newsize_ok(const struct inode *, loff_t offset); void setattr_copy(struct user_namespace *, struct inode *inode, |