From 8b8efb44033c7e86b3dc76f825c693ec92ae30e9 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa Date: Sun, 4 Oct 2009 21:49:48 +0900 Subject: [PATCH] LSM: Add security_path_chroot(). This patch allows pathname based LSM modules to check chroot() operations. This hook is used by TOMOYO. Signed-off-by: Tetsuo Handa Signed-off-by: James Morris --- fs/open.c | 3 +++ include/linux/security.h | 11 +++++++++++ security/capability.c | 6 ++++++ security/security.c | 5 +++++ 4 files changed, 25 insertions(+) diff --git a/fs/open.c b/fs/open.c index b5c294d35bd..201041dfca5 100644 --- a/fs/open.c +++ b/fs/open.c @@ -587,6 +587,9 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename) error = -EPERM; if (!capable(CAP_SYS_CHROOT)) goto dput_and_out; + error = security_path_chroot(&path); + if (error) + goto dput_and_out; set_fs_root(current->fs, &path); error = 0; diff --git a/include/linux/security.h b/include/linux/security.h index c8a584c26f7..ed0faea60b8 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -459,6 +459,10 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) * @uid contains new owner's ID. * @gid contains new group's ID. * Return 0 if permission is granted. + * @path_chroot: + * Check for permission to change root directory. + * @path contains the path structure. + * 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. @@ -1503,6 +1507,7 @@ struct security_operations { int (*path_chmod) (struct dentry *dentry, struct vfsmount *mnt, mode_t mode); int (*path_chown) (struct path *path, uid_t uid, gid_t gid); + int (*path_chroot) (struct path *path); #endif int (*inode_alloc_security) (struct inode *inode); @@ -2970,6 +2975,7 @@ int security_path_rename(struct path *old_dir, struct dentry *old_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); +int security_path_chroot(struct path *path); #else /* CONFIG_SECURITY_PATH */ static inline int security_path_unlink(struct path *dir, struct dentry *dentry) { @@ -3031,6 +3037,11 @@ static inline int security_path_chown(struct path *path, uid_t uid, gid_t gid) { return 0; } + +static inline int security_path_chroot(struct path *path) +{ + return 0; +} #endif /* CONFIG_SECURITY_PATH */ #ifdef CONFIG_KEYS diff --git a/security/capability.c b/security/capability.c index 09279a8d4a1..4f3ab476937 100644 --- a/security/capability.c +++ b/security/capability.c @@ -319,6 +319,11 @@ static int cap_path_chown(struct path *path, uid_t uid, gid_t gid) { return 0; } + +static int cap_path_chroot(struct path *root) +{ + return 0; +} #endif static int cap_file_permission(struct file *file, int mask) @@ -990,6 +995,7 @@ void security_fixup_ops(struct security_operations *ops) set_to_cap_if_null(ops, path_truncate); set_to_cap_if_null(ops, path_chmod); set_to_cap_if_null(ops, path_chown); + set_to_cap_if_null(ops, path_chroot); #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 5259270e558..279757314a0 100644 --- a/security/security.c +++ b/security/security.c @@ -449,6 +449,11 @@ int security_path_chown(struct path *path, uid_t uid, gid_t gid) return 0; return security_ops->path_chown(path, uid, gid); } + +int security_path_chroot(struct path *path) +{ + return security_ops->path_chroot(path); +} #endif int security_inode_create(struct inode *dir, struct dentry *dentry, int mode)