diff options
| -rw-r--r-- | fs/open.c | 24 | ||||
| -rw-r--r-- | include/linux/security.h | 30 | ||||
| -rw-r--r-- | security/capability.c | 13 | ||||
| -rw-r--r-- | security/security.c | 15 |
4 files changed, 78 insertions, 4 deletions
@@ -616,6 +616,9 @@ SYSCALL_DEFINE2(fchmod, unsigned int, fd, mode_t, mode) err = mnt_want_write_file(file); if (err) goto out_putf; + err = security_path_chmod(dentry, file->f_vfsmnt, mode); + if (err) + goto out_drop_write; mutex_lock(&inode->i_mutex); if (mode == (mode_t) -1) mode = inode->i_mode; @@ -623,6 +626,7 @@ SYSCALL_DEFINE2(fchmod, unsigned int, fd, mode_t, mode) newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; err = notify_change(dentry, &newattrs); mutex_unlock(&inode->i_mutex); +out_drop_write: mnt_drop_write(file->f_path.mnt); out_putf: fput(file); @@ -645,6 +649,9 @@ SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, mode_t, mode) error = mnt_want_write(path.mnt); if (error) goto dput_and_out; + error = security_path_chmod(path.dentry, path.mnt, mode); + if (error) + goto out_drop_write; mutex_lock(&inode->i_mutex); if (mode == (mode_t) -1) mode = inode->i_mode; @@ -652,6 +659,7 @@ SYSCALL_DEFINE3(fchmodat, int, dfd, const char __user *, filename, mode_t, mode) newattrs.ia_valid = ATTR_MODE | ATTR_CTIME; error = notify_change(path.dentry, &newattrs); mutex_unlock(&inode->i_mutex); +out_drop_write: mnt_drop_write(path.mnt); dput_and_out: path_put(&path); @@ -700,7 +708,9 @@ SYSCALL_DEFINE3(chown, const char __user *, filename, uid_t, user, gid_t, group) error = mnt_want_write(path.mnt); if (error) goto out_release; - error = chown_common(path.dentry, user, group); + error = security_path_chown(&path, user, group); + if (!error) + error = chown_common(path.dentry, user, group); mnt_drop_write(path.mnt); out_release: path_put(&path); @@ -725,7 +735,9 @@ SYSCALL_DEFINE5(fchownat, int, dfd, const char __user *, filename, uid_t, user, error = mnt_want_write(path.mnt); if (error) goto out_release; - error = chown_common(path.dentry, user, group); + error = security_path_chown(&path, user, group); + if (!error) + error = chown_common(path.dentry, user, group); mnt_drop_write(path.mnt); out_release: path_put(&path); @@ -744,7 +756,9 @@ SYSCALL_DEFINE3(lchown, const char __user *, filename, uid_t, user, gid_t, group error = mnt_want_write(path.mnt); if (error) goto out_release; - error = chown_common(path.dentry, user, group); + error = security_path_chown(&path, user, group); + if (!error) + error = chown_common(path.dentry, user, group); mnt_drop_write(path.mnt); out_release: path_put(&path); @@ -767,7 +781,9 @@ SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group) goto out_fput; dentry = file->f_path.dentry; audit_inode(NULL, dentry); - error = chown_common(dentry, user, group); + error = security_path_chown(&file->f_path, user, group); + if (!error) + error = chown_common(dentry, user, group); mnt_drop_write(file->f_path.mnt); out_fput: fput(file); diff --git a/include/linux/security.h b/include/linux/security.h index 239e40d..c8a584c 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -447,6 +447,18 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @new_dir contains the path structure for parent of the new link. * @new_dentry contains the dentry structure of the new link. * Return 0 if permission is granted. + * @path_chmod: + * Check for permission to change DAC's permission of a file or directory. + * @dentry contains the dentry structure. + * @mnt contains the vfsmnt structure. + * @mode contains DAC's mode. + * Return 0 if permission is granted. + * @path_chown: + * Check for permission to change owner/group of a file or directory. + * @path contains the path structure. + * @uid contains new owner's ID. + * @gid contains new group's ID. + * Return 0 if permission is granted. * @inode_readlink: * Check the permission to read the symbolic link. * @dentry contains the dentry structure for the file link. @@ -1488,6 +1500,9 @@ struct security_operations { struct dentry *new_dentry); int (*path_rename) (struct path *old_dir, struct dentry *old_dentry, struct path *new_dir, struct dentry *new_dentry); + int (*path_chmod) (struct dentry *dentry, struct vfsmount *mnt, + mode_t mode); + int (*path_chown) (struct path *path, uid_t uid, gid_t gid); #endif int (*inode_alloc_security) (struct inode *inode); @@ -2952,6 +2967,9 @@ int security_path_link(struct dentry *old_dentry, struct path *new_dir, struct dentry *new_dentry); int security_path_rename(struct path *old_dir, struct dentry *old_dentry, struct path *new_dir, struct dentry *new_dentry); +int security_path_chmod(struct dentry *dentry, struct vfsmount *mnt, + mode_t mode); +int security_path_chown(struct path *path, uid_t uid, gid_t gid); #else /* CONFIG_SECURITY_PATH */ static inline int security_path_unlink(struct path *dir, struct dentry *dentry) { @@ -3001,6 +3019,18 @@ static inline int security_path_rename(struct path *old_dir, { return 0; } + +static inline int security_path_chmod(struct dentry *dentry, + struct vfsmount *mnt, + mode_t mode) +{ + return 0; +} + +static inline int security_path_chown(struct path *path, uid_t uid, gid_t gid) +{ + return 0; +} #endif /* CONFIG_SECURITY_PATH */ #ifdef CONFIG_KEYS diff --git a/security/capability.c b/security/capability.c index fce07a7..09279a8 100644 --- a/security/capability.c +++ b/security/capability.c @@ -308,6 +308,17 @@ static int cap_path_truncate(struct path *path, loff_t length, { return 0; } + +static int cap_path_chmod(struct dentry *dentry, struct vfsmount *mnt, + mode_t mode) +{ + return 0; +} + +static int cap_path_chown(struct path *path, uid_t uid, gid_t gid) +{ + return 0; +} #endif static int cap_file_permission(struct file *file, int mask) @@ -977,6 +988,8 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, path_link); set_to_cap_if_null(ops, path_rename); set_to_cap_if_null(ops, path_truncate); + set_to_cap_if_null(ops, path_chmod); + set_to_cap_if_null(ops, path_chown); #endif set_to_cap_if_null(ops, file_permission); set_to_cap_if_null(ops, file_alloc_security); diff --git a/security/security.c b/security/security.c index c4c6732..5259270 100644 --- a/security/security.c +++ b/security/security.c @@ -434,6 +434,21 @@ int security_path_truncate(struct path *path, loff_t length, return 0; return security_ops->path_truncate(path, length, time_attrs); } + +int security_path_chmod(struct dentry *dentry, struct vfsmount *mnt, + mode_t mode) +{ + if (unlikely(IS_PRIVATE(dentry->d_inode))) + return 0; + return security_ops->path_chmod(dentry, mnt, mode); +} + +int security_path_chown(struct path *path, uid_t uid, gid_t gid) +{ + if (unlikely(IS_PRIVATE(path->dentry->d_inode))) + return 0; + return security_ops->path_chown(path, uid, gid); +} #endif int security_inode_create(struct inode *dir, struct dentry *dentry, int mode) |
