Get rid of passing mangled flag to do_last()
[safe/jmp/linux-2.6] / security / tomoyo / tomoyo.c
index 35a13e7..dedd97d 100644 (file)
 
 #include <linux/security.h>
 #include "common.h"
-#include "tomoyo.h"
-#include "realpath.h"
+
+static int tomoyo_cred_alloc_blank(struct cred *new, gfp_t gfp)
+{
+       new->security = NULL;
+       return 0;
+}
 
 static int tomoyo_cred_prepare(struct cred *new, const struct cred *old,
                               gfp_t gfp)
 {
-       /*
-        * Since "struct tomoyo_domain_info *" is a sharable pointer,
-        * we don't need to duplicate.
-        */
-       new->security = old->security;
+       struct tomoyo_domain_info *domain = old->security;
+       new->security = domain;
+       if (domain)
+               atomic_inc(&domain->users);
        return 0;
 }
 
+static void tomoyo_cred_transfer(struct cred *new, const struct cred *old)
+{
+       tomoyo_cred_prepare(new, old, 0);
+}
+
+static void tomoyo_cred_free(struct cred *cred)
+{
+       struct tomoyo_domain_info *domain = cred->security;
+       if (domain)
+               atomic_dec(&domain->users);
+}
+
 static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
 {
        int rc;
@@ -46,6 +61,14 @@ static int tomoyo_bprm_set_creds(struct linux_binprm *bprm)
        if (!tomoyo_policy_loaded)
                tomoyo_load_policy(bprm->filename);
        /*
+        * Release reference to "struct tomoyo_domain_info" stored inside
+        * "bprm->cred->security". New reference to "struct tomoyo_domain_info"
+        * stored inside "bprm->cred->security" will be acquired later inside
+        * tomoyo_find_next_domain().
+        */
+       atomic_dec(&((struct tomoyo_domain_info *)
+                    bprm->cred->security)->users);
+       /*
         * Tell tomoyo_bprm_check_security() is called for the first time of an
         * execve operation.
         */
@@ -61,156 +84,71 @@ static int tomoyo_bprm_check_security(struct linux_binprm *bprm)
         * Execute permission is checked against pathname passed to do_execve()
         * using current domain.
         */
-       if (!domain)
-               return tomoyo_find_next_domain(bprm);
+       if (!domain) {
+               const int idx = tomoyo_read_lock();
+               const int err = tomoyo_find_next_domain(bprm);
+               tomoyo_read_unlock(idx);
+               return err;
+       }
        /*
         * Read permission is checked against interpreters using next domain.
-        * '1' is the result of open_to_namei_flags(O_RDONLY).
         */
-       return tomoyo_check_open_permission(domain, &bprm->file->f_path, 1);
+       return tomoyo_check_open_permission(domain, &bprm->file->f_path, O_RDONLY);
 }
 
-#ifdef CONFIG_SYSCTL
-
-static int tomoyo_prepend(char **buffer, int *buflen, const char *str)
-{
-       int namelen = strlen(str);
-
-       if (*buflen < namelen)
-               return -ENOMEM;
-       *buflen -= namelen;
-       *buffer -= namelen;
-       memcpy(*buffer, str, namelen);
-       return 0;
-}
-
-/**
- * tomoyo_sysctl_path - return the realpath of a ctl_table.
- * @table: pointer to "struct ctl_table".
- *
- * Returns realpath(3) of the @table on success.
- * Returns NULL on failure.
- *
- * This function uses tomoyo_alloc(), so the caller must call tomoyo_free()
- * if this function didn't return NULL.
- */
-static char *tomoyo_sysctl_path(struct ctl_table *table)
-{
-       int buflen = TOMOYO_MAX_PATHNAME_LEN;
-       char *buf = tomoyo_alloc(buflen);
-       char *end = buf + buflen;
-       int error = -ENOMEM;
-
-       if (!buf)
-               return NULL;
-
-       *--end = '\0';
-       buflen--;
-       while (table) {
-               char num[32];
-               const char *sp = table->procname;
-
-               if (!sp) {
-                       memset(num, 0, sizeof(num));
-                       snprintf(num, sizeof(num) - 1, "=%d=", table->ctl_name);
-                       sp = num;
-               }
-               if (tomoyo_prepend(&end, &buflen, sp) ||
-                   tomoyo_prepend(&end, &buflen, "/"))
-                       goto out;
-               table = table->parent;
-       }
-       if (tomoyo_prepend(&end, &buflen, "/proc/sys"))
-               goto out;
-       error = tomoyo_encode(buf, end - buf, end);
- out:
-       if (!error)
-               return buf;
-       tomoyo_free(buf);
-       return NULL;
-}
-
-static int tomoyo_sysctl(struct ctl_table *table, int op)
-{
-       int error;
-       char *name;
-
-       op &= MAY_READ | MAY_WRITE;
-       if (!op)
-               return 0;
-       name = tomoyo_sysctl_path(table);
-       if (!name)
-               return -ENOMEM;
-       error = tomoyo_check_file_perm(tomoyo_domain(), name, op);
-       tomoyo_free(name);
-       return error;
-}
-#endif
-
 static int tomoyo_path_truncate(struct path *path, loff_t length,
                                unsigned int time_attrs)
 {
-       return tomoyo_check_1path_perm(tomoyo_domain(),
-                                      TOMOYO_TYPE_TRUNCATE_ACL,
-                                      path);
+       return tomoyo_path_perm(TOMOYO_TYPE_TRUNCATE, path);
 }
 
 static int tomoyo_path_unlink(struct path *parent, struct dentry *dentry)
 {
        struct path path = { parent->mnt, dentry };
-       return tomoyo_check_1path_perm(tomoyo_domain(),
-                                      TOMOYO_TYPE_UNLINK_ACL,
-                                      &path);
+       return tomoyo_path_perm(TOMOYO_TYPE_UNLINK, &path);
 }
 
 static int tomoyo_path_mkdir(struct path *parent, struct dentry *dentry,
                             int mode)
 {
        struct path path = { parent->mnt, dentry };
-       return tomoyo_check_1path_perm(tomoyo_domain(),
-                                      TOMOYO_TYPE_MKDIR_ACL,
-                                      &path);
+       return tomoyo_path_perm(TOMOYO_TYPE_MKDIR, &path);
 }
 
 static int tomoyo_path_rmdir(struct path *parent, struct dentry *dentry)
 {
        struct path path = { parent->mnt, dentry };
-       return tomoyo_check_1path_perm(tomoyo_domain(),
-                                      TOMOYO_TYPE_RMDIR_ACL,
-                                      &path);
+       return tomoyo_path_perm(TOMOYO_TYPE_RMDIR, &path);
 }
 
 static int tomoyo_path_symlink(struct path *parent, struct dentry *dentry,
                               const char *old_name)
 {
        struct path path = { parent->mnt, dentry };
-       return tomoyo_check_1path_perm(tomoyo_domain(),
-                                      TOMOYO_TYPE_SYMLINK_ACL,
-                                      &path);
+       return tomoyo_path_perm(TOMOYO_TYPE_SYMLINK, &path);
 }
 
 static int tomoyo_path_mknod(struct path *parent, struct dentry *dentry,
                             int mode, unsigned int dev)
 {
        struct path path = { parent->mnt, dentry };
-       int type = TOMOYO_TYPE_CREATE_ACL;
+       int type = TOMOYO_TYPE_CREATE;
 
        switch (mode & S_IFMT) {
        case S_IFCHR:
-               type = TOMOYO_TYPE_MKCHAR_ACL;
+               type = TOMOYO_TYPE_MKCHAR;
                break;
        case S_IFBLK:
-               type = TOMOYO_TYPE_MKBLOCK_ACL;
+               type = TOMOYO_TYPE_MKBLOCK;
                break;
        case S_IFIFO:
-               type = TOMOYO_TYPE_MKFIFO_ACL;
+               type = TOMOYO_TYPE_MKFIFO;
                break;
        case S_IFSOCK:
-               type = TOMOYO_TYPE_MKSOCK_ACL;
+               type = TOMOYO_TYPE_MKSOCK;
                break;
        }
-       return tomoyo_check_1path_perm(tomoyo_domain(),
-                                      type, &path);
+       return tomoyo_path_perm(type, &path);
 }
 
 static int tomoyo_path_link(struct dentry *old_dentry, struct path *new_dir,
@@ -218,9 +156,7 @@ static int tomoyo_path_link(struct dentry *old_dentry, struct path *new_dir,
 {
        struct path path1 = { new_dir->mnt, old_dentry };
        struct path path2 = { new_dir->mnt, new_dentry };
-       return tomoyo_check_2path_perm(tomoyo_domain(),
-                                      TOMOYO_TYPE_LINK_ACL,
-                                      &path1, &path2);
+       return tomoyo_path2_perm(TOMOYO_TYPE_LINK, &path1, &path2);
 }
 
 static int tomoyo_path_rename(struct path *old_parent,
@@ -230,44 +166,83 @@ static int tomoyo_path_rename(struct path *old_parent,
 {
        struct path path1 = { old_parent->mnt, old_dentry };
        struct path path2 = { new_parent->mnt, new_dentry };
-       return tomoyo_check_2path_perm(tomoyo_domain(),
-                                      TOMOYO_TYPE_RENAME_ACL,
-                                      &path1, &path2);
+       return tomoyo_path2_perm(TOMOYO_TYPE_RENAME, &path1, &path2);
 }
 
 static int tomoyo_file_fcntl(struct file *file, unsigned int cmd,
                             unsigned long arg)
 {
        if (cmd == F_SETFL && ((arg ^ file->f_flags) & O_APPEND))
-               return tomoyo_check_rewrite_permission(tomoyo_domain(), file);
+               return tomoyo_check_rewrite_permission(file);
        return 0;
 }
 
 static int tomoyo_dentry_open(struct file *f, const struct cred *cred)
 {
        int flags = f->f_flags;
-
-       if ((flags + 1) & O_ACCMODE)
-               flags++;
-       flags |= f->f_flags & (O_APPEND | O_TRUNC);
        /* Don't check read permission here if called from do_execve(). */
        if (current->in_execve)
                return 0;
        return tomoyo_check_open_permission(tomoyo_domain(), &f->f_path, flags);
 }
 
+static int tomoyo_file_ioctl(struct file *file, unsigned int cmd,
+                            unsigned long arg)
+{
+       return tomoyo_path_perm(TOMOYO_TYPE_IOCTL, &file->f_path);
+}
+
+static int tomoyo_path_chmod(struct dentry *dentry, struct vfsmount *mnt,
+                            mode_t mode)
+{
+       struct path path = { mnt, dentry };
+       return tomoyo_path_perm(TOMOYO_TYPE_CHMOD, &path);
+}
+
+static int tomoyo_path_chown(struct path *path, uid_t uid, gid_t gid)
+{
+       int error = 0;
+       if (uid != (uid_t) -1)
+               error = tomoyo_path_perm(TOMOYO_TYPE_CHOWN, path);
+       if (!error && gid != (gid_t) -1)
+               error = tomoyo_path_perm(TOMOYO_TYPE_CHGRP, path);
+       return error;
+}
+
+static int tomoyo_path_chroot(struct path *path)
+{
+       return tomoyo_path_perm(TOMOYO_TYPE_CHROOT, path);
+}
+
+static int tomoyo_sb_mount(char *dev_name, struct path *path,
+                          char *type, unsigned long flags, void *data)
+{
+       return tomoyo_path_perm(TOMOYO_TYPE_MOUNT, path);
+}
+
+static int tomoyo_sb_umount(struct vfsmount *mnt, int flags)
+{
+       struct path path = { mnt, mnt->mnt_root };
+       return tomoyo_path_perm(TOMOYO_TYPE_UMOUNT, &path);
+}
+
+static int tomoyo_sb_pivotroot(struct path *old_path, struct path *new_path)
+{
+       return tomoyo_path2_perm(TOMOYO_TYPE_PIVOT_ROOT, new_path, old_path);
+}
+
 /*
  * tomoyo_security_ops is a "struct security_operations" which is used for
  * registering TOMOYO.
  */
 static struct security_operations tomoyo_security_ops = {
        .name                = "tomoyo",
+       .cred_alloc_blank    = tomoyo_cred_alloc_blank,
        .cred_prepare        = tomoyo_cred_prepare,
+       .cred_transfer       = tomoyo_cred_transfer,
+       .cred_free           = tomoyo_cred_free,
        .bprm_set_creds      = tomoyo_bprm_set_creds,
        .bprm_check_security = tomoyo_bprm_check_security,
-#ifdef CONFIG_SYSCTL
-       .sysctl              = tomoyo_sysctl,
-#endif
        .file_fcntl          = tomoyo_file_fcntl,
        .dentry_open         = tomoyo_dentry_open,
        .path_truncate       = tomoyo_path_truncate,
@@ -278,8 +253,18 @@ static struct security_operations tomoyo_security_ops = {
        .path_mknod          = tomoyo_path_mknod,
        .path_link           = tomoyo_path_link,
        .path_rename         = tomoyo_path_rename,
+       .file_ioctl          = tomoyo_file_ioctl,
+       .path_chmod          = tomoyo_path_chmod,
+       .path_chown          = tomoyo_path_chown,
+       .path_chroot         = tomoyo_path_chroot,
+       .sb_mount            = tomoyo_sb_mount,
+       .sb_umount           = tomoyo_sb_umount,
+       .sb_pivotroot        = tomoyo_sb_pivotroot,
 };
 
+/* Lock for GC. */
+struct srcu_struct tomoyo_ss;
+
 static int __init tomoyo_init(void)
 {
        struct cred *cred = (struct cred *) current_cred();
@@ -287,7 +272,8 @@ static int __init tomoyo_init(void)
        if (!security_module_enable(&tomoyo_security_ops))
                return 0;
        /* register ourselves with the security framework */
-       if (register_security(&tomoyo_security_ops))
+       if (register_security(&tomoyo_security_ops) ||
+           init_srcu_struct(&tomoyo_ss))
                panic("Failure registering TOMOYO Linux");
        printk(KERN_INFO "TOMOYO Linux initialized\n");
        cred->security = &tomoyo_kernel_domain;