Merge branch 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs mount API prep from Al Viro:
 "Mount API prereqs.

  Mostly that's LSM mount options cleanups. There are several minor
  fixes in there, but nothing earth-shattering (leaks on failure exits,
  mostly)"

* 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits)
  mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT
  smack: rewrite smack_sb_eat_lsm_opts()
  smack: get rid of match_token()
  smack: take the guts of smack_parse_opts_str() into a new helper
  LSM: new method: ->sb_add_mnt_opt()
  selinux: rewrite selinux_sb_eat_lsm_opts()
  selinux: regularize Opt_... names a bit
  selinux: switch away from match_token()
  selinux: new helper - selinux_add_opt()
  LSM: bury struct security_mnt_opts
  smack: switch to private smack_mnt_opts
  selinux: switch to private struct selinux_mnt_opts
  LSM: hide struct security_mnt_opts from any generic code
  selinux: kill selinux_sb_get_mnt_opts()
  LSM: turn sb_eat_lsm_opts() into a method
  nfs_remount(): don't leak, don't ignore LSM options quietly
  btrfs: sanitize security_mnt_opts use
  selinux; don't open-code a loop in sb_finish_set_opts()
  LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount()
  new helper: security_sb_eat_lsm_opts()
  ...

arch/arc/kernel/setup.c

@@ -19,6 +19,7 @@
 #include <linux/of_fdt.h>
 #include <linux/of.h>
 #include <linux/cache.h>
+#include <uapi/linux/mount.h>
 #include <asm/sections.h>
 #include <asm/arcregs.h>
 #include <asm/tlb.h>

arch/arm/kernel/atags_parse.c

@@ -24,6 +24,7 @@
 #include <linux/root_dev.h>
 #include <linux/screen_info.h>
 #include <linux/memblock.h>
+#include <uapi/linux/mount.h>
 
 #include <asm/setup.h>
 #include <asm/system_info.h>

arch/sh/kernel/setup.c

@@ -32,6 +32,7 @@
 #include <linux/of.h>
 #include <linux/of_fdt.h>
 #include <linux/uaccess.h>
+#include <uapi/linux/mount.h>
 #include <asm/io.h>
 #include <asm/page.h>
 #include <asm/elf.h>

arch/sparc/kernel/setup_32.c

@@ -34,6 +34,7 @@
 #include <linux/kdebug.h>
 #include <linux/export.h>
 #include <linux/start_kernel.h>
+#include <uapi/linux/mount.h>
 
 #include <asm/io.h>
 #include <asm/processor.h>

arch/sparc/kernel/setup_64.c

@@ -33,6 +33,7 @@
 #include <linux/module.h>
 #include <linux/start_kernel.h>
 #include <linux/memblock.h>
+#include <uapi/linux/mount.h>
 
 #include <asm/io.h>
 #include <asm/processor.h>

arch/x86/kernel/setup.c

@@ -50,6 +50,7 @@
 #include <linux/kvm_para.h>
 #include <linux/dma-contiguous.h>
 #include <xen/xen.h>
+#include <uapi/linux/mount.h>
 
 #include <linux/errno.h>
 #include <linux/kernel.h>

drivers/base/devtmpfs.c

@@ -25,6 +25,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/kthread.h>
+#include <uapi/linux/mount.h>
 #include "base.h"
 
 static struct task_struct *thread;

fs/btrfs/ctree.h

@@ -1144,9 +1144,6 @@ struct btrfs_fs_info {
 	struct mutex unused_bg_unpin_mutex;
 	struct mutex delete_unused_bgs_mutex;
 
-	/* For btrfs to record security options */
-	struct security_mnt_opts security_opts;
-
 	/*
 	 * Chunks that can't be freed yet (under a trim/discard operation)
 	 * and will be latter freed. Protected by fs_info->chunk_mutex.
@@ -3021,7 +3018,6 @@ static inline void free_fs_info(struct btrfs_fs_info *fs_info)
 	kfree(fs_info->free_space_root);
 	kfree(fs_info->super_copy);
 	kfree(fs_info->super_for_commit);
-	security_free_mnt_opts(&fs_info->security_opts);
 	kvfree(fs_info);
 }
 

fs/btrfs/super.c

@@ -1458,56 +1458,6 @@ static struct dentry *mount_subvol(const char *subvol_name, u64 subvol_objectid,
 	return root;
 }
 
-static int parse_security_options(char *orig_opts,
-				  struct security_mnt_opts *sec_opts)
-{
-	char *secdata = NULL;
-	int ret = 0;
-
-	secdata = alloc_secdata();
-	if (!secdata)
-		return -ENOMEM;
-	ret = security_sb_copy_data(orig_opts, secdata);
-	if (ret) {
-		free_secdata(secdata);
-		return ret;
-	}
-	ret = security_sb_parse_opts_str(secdata, sec_opts);
-	free_secdata(secdata);
-	return ret;
-}
-
-static int setup_security_options(struct btrfs_fs_info *fs_info,
-				  struct super_block *sb,
-				  struct security_mnt_opts *sec_opts)
-{
-	int ret = 0;
-
-	/*
-	 * Call security_sb_set_mnt_opts() to check whether new sec_opts
-	 * is valid.
-	 */
-	ret = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
-	if (ret)
-		return ret;
-
-#ifdef CONFIG_SECURITY
-	if (!fs_info->security_opts.num_mnt_opts) {
-		/* first time security setup, copy sec_opts to fs_info */
-		memcpy(&fs_info->security_opts, sec_opts, sizeof(*sec_opts));
-	} else {
-		/*
-		 * Since SELinux (the only one supporting security_mnt_opts)
-		 * does NOT support changing context during remount/mount of
-		 * the same sb, this must be the same or part of the same
-		 * security options, just free it.
-		 */
-		security_free_mnt_opts(sec_opts);
-	}
-#endif
-	return ret;
-}
-
 /*
  * Find a superblock for the given device / mount point.
  *
@@ -1522,16 +1472,15 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
 	struct btrfs_device *device = NULL;
 	struct btrfs_fs_devices *fs_devices = NULL;
 	struct btrfs_fs_info *fs_info = NULL;
-	struct security_mnt_opts new_sec_opts;
+	void *new_sec_opts = NULL;
 	fmode_t mode = FMODE_READ;
 	int error = 0;
 
 	if (!(flags & SB_RDONLY))
 		mode |= FMODE_WRITE;
 
-	security_init_mnt_opts(&new_sec_opts);
 	if (data) {
-		error = parse_security_options(data, &new_sec_opts);
+		error = security_sb_eat_lsm_opts(data, &new_sec_opts);
 		if (error)
 			return ERR_PTR(error);
 	}
@@ -1550,7 +1499,6 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
 
 	fs_info->super_copy = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
 	fs_info->super_for_commit = kzalloc(BTRFS_SUPER_INFO_SIZE, GFP_KERNEL);
-	security_init_mnt_opts(&fs_info->security_opts);
 	if (!fs_info->super_copy || !fs_info->super_for_commit) {
 		error = -ENOMEM;
 		goto error_fs_info;
@@ -1601,16 +1549,12 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
 		btrfs_sb(s)->bdev_holder = fs_type;
 		error = btrfs_fill_super(s, fs_devices, data);
 	}
+	if (!error)
+		error = security_sb_set_mnt_opts(s, new_sec_opts, 0, NULL);
+	security_free_mnt_opts(&new_sec_opts);
 	if (error) {
 		deactivate_locked_super(s);
-		goto error_sec_opts;
-	}
-
-	fs_info = btrfs_sb(s);
-	error = setup_security_options(fs_info, s, &new_sec_opts);
-	if (error) {
-		deactivate_locked_super(s);
-		goto error_sec_opts;
+		return ERR_PTR(error);
 	}
 
 	return dget(s->s_root);
@@ -1779,19 +1723,15 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data)
 	btrfs_remount_prepare(fs_info);
 
 	if (data) {
-		struct security_mnt_opts new_sec_opts;
+		void *new_sec_opts = NULL;
 
-		security_init_mnt_opts(&new_sec_opts);
-		ret = parse_security_options(data, &new_sec_opts);
-		if (ret)
-			goto restore;
-		ret = setup_security_options(fs_info, sb,
-					     &new_sec_opts);
-		if (ret) {
+		ret = security_sb_eat_lsm_opts(data, &new_sec_opts);
+		if (!ret)
+			ret = security_sb_remount(sb, new_sec_opts);
 		security_free_mnt_opts(&new_sec_opts);
+		if (ret)
 			goto restore;
 	}
-	}
 
 	ret = btrfs_parse_options(fs_info, data, *flags);
 	if (ret)

fs/exofs/super.c

@@ -705,21 +705,18 @@ static int exofs_read_lookup_dev_table(struct exofs_sb_info *sbi,
 /*
  * Read the superblock from the OSD and fill in the fields
  */
-static int exofs_fill_super(struct super_block *sb, void *data, int silent)
+static int exofs_fill_super(struct super_block *sb,
+				struct exofs_mountopt *opts,
+				struct exofs_sb_info *sbi,
+				int silent)
 {
 	struct inode *root;
-	struct exofs_mountopt *opts = data;
-	struct exofs_sb_info *sbi;	/*extended info                  */
 	struct osd_dev *od;		/* Master device                 */
 	struct exofs_fscb fscb;		/*on-disk superblock info        */
 	struct ore_comp comp;
 	unsigned table_count;
 	int ret;
 
-	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
-	if (!sbi)
-		return -ENOMEM;
-
 	/* use mount options to fill superblock */
 	if (opts->is_osdname) {
 		struct osd_dev_info odi = {.systemid_len = 0};
@@ -863,7 +860,9 @@ static struct dentry *exofs_mount(struct file_system_type *type,
 			  int flags, const char *dev_name,
 			  void *data)
 {
+	struct super_block *s;
 	struct exofs_mountopt opts;
+	struct exofs_sb_info *sbi;
 	int ret;
 
 	ret = parse_options(data, &opts);
@@ -872,9 +871,31 @@ static struct dentry *exofs_mount(struct file_system_type *type,
 		return ERR_PTR(ret);
 	}
 
+	sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
+	if (!sbi) {
+		kfree(opts.dev_name);
+		return ERR_PTR(-ENOMEM);
+	}
+
+	s = sget(type, NULL, set_anon_super, flags, NULL);
+
+	if (IS_ERR(s)) {
+		kfree(opts.dev_name);
+		kfree(sbi);
+		return ERR_CAST(s);
+	}
+
 	if (!opts.dev_name)
 		opts.dev_name = dev_name;
-	return mount_nodev(type, flags, &opts, exofs_fill_super);
+
+
+	ret = exofs_fill_super(s, &opts, sbi, flags & SB_SILENT ? 1 : 0);
+	if (ret) {
+		deactivate_locked_super(s);
+		return ERR_PTR(ret);
+	}
+	s->s_flags |= SB_ACTIVE;
+	return dget(s->s_root);
 }
 
 /*

fs/namespace.c

@@ -26,6 +26,7 @@
 #include <linux/memblock.h>
 #include <linux/task_work.h>
 #include <linux/sched/task.h>
+#include <uapi/linux/mount.h>
 
 #include "pnode.h"
 #include "internal.h"
@@ -245,13 +246,9 @@ static struct mount *alloc_vfsmnt(const char *name)
  * mnt_want/drop_write() will _keep_ the filesystem
  * r/w.
  */
-int __mnt_is_readonly(struct vfsmount *mnt)
+bool __mnt_is_readonly(struct vfsmount *mnt)
 {
-	if (mnt->mnt_flags & MNT_READONLY)
-		return 1;
-	if (sb_rdonly(mnt->mnt_sb))
-		return 1;
-	return 0;
+	return (mnt->mnt_flags & MNT_READONLY) || sb_rdonly(mnt->mnt_sb);
 }
 EXPORT_SYMBOL_GPL(__mnt_is_readonly);
 
@@ -507,11 +504,12 @@ static int mnt_make_readonly(struct mount *mnt)
 	return ret;
 }
 
-static void __mnt_unmake_readonly(struct mount *mnt)
+static int __mnt_unmake_readonly(struct mount *mnt)
 {
 	lock_mount_hash();
 	mnt->mnt.mnt_flags &= ~MNT_READONLY;
 	unlock_mount_hash();
+	return 0;
 }
 
 int sb_prepare_remount_readonly(struct super_block *sb)
@@ -2215,21 +2213,91 @@ static int do_loopback(struct path *path, const char *old_name,
 	return err;
 }
 
-static int change_mount_flags(struct vfsmount *mnt, int ms_flags)
+/*
+ * Don't allow locked mount flags to be cleared.
+ *
+ * No locks need to be held here while testing the various MNT_LOCK
+ * flags because those flags can never be cleared once they are set.
+ */
+static bool can_change_locked_flags(struct mount *mnt, unsigned int mnt_flags)
+{
+	unsigned int fl = mnt->mnt.mnt_flags;
+
+	if ((fl & MNT_LOCK_READONLY) &&
+	    !(mnt_flags & MNT_READONLY))
+		return false;
+
+	if ((fl & MNT_LOCK_NODEV) &&
+	    !(mnt_flags & MNT_NODEV))
+		return false;
+
+	if ((fl & MNT_LOCK_NOSUID) &&
+	    !(mnt_flags & MNT_NOSUID))
+		return false;
+
+	if ((fl & MNT_LOCK_NOEXEC) &&
+	    !(mnt_flags & MNT_NOEXEC))
+		return false;
+
+	if ((fl & MNT_LOCK_ATIME) &&
+	    ((fl & MNT_ATIME_MASK) != (mnt_flags & MNT_ATIME_MASK)))
+		return false;
+
+	return true;
+}
+
+static int change_mount_ro_state(struct mount *mnt, unsigned int mnt_flags)
 {
-	int error = 0;
-	int readonly_request = 0;
+	bool readonly_request = (mnt_flags & MNT_READONLY);
 
-	if (ms_flags & MS_RDONLY)
-		readonly_request = 1;
-	if (readonly_request == __mnt_is_readonly(mnt))
+	if (readonly_request == __mnt_is_readonly(&mnt->mnt))
 		return 0;
 
 	if (readonly_request)
-		error = mnt_make_readonly(real_mount(mnt));
-	else
-		__mnt_unmake_readonly(real_mount(mnt));
-	return error;
+		return mnt_make_readonly(mnt);
+
+	return __mnt_unmake_readonly(mnt);
+}
+
+/*
+ * Update the user-settable attributes on a mount.  The caller must hold
+ * sb->s_umount for writing.
+ */
+static void set_mount_attributes(struct mount *mnt, unsigned int mnt_flags)
+{
+	lock_mount_hash();
+	mnt_flags |= mnt->mnt.mnt_flags & ~MNT_USER_SETTABLE_MASK;
+	mnt->mnt.mnt_flags = mnt_flags;
+	touch_mnt_namespace(mnt->mnt_ns);
+	unlock_mount_hash();
+}
+
+/*
+ * Handle reconfiguration of the mountpoint only without alteration of the
+ * superblock it refers to.  This is triggered by specifying MS_REMOUNT|MS_BIND
+ * to mount(2).
+ */
+static int do_reconfigure_mnt(struct path *path, unsigned int mnt_flags)
+{
+	struct super_block *sb = path->mnt->mnt_sb;
+	struct mount *mnt = real_mount(path->mnt);
+	int ret;
+
+	if (!check_mnt(mnt))
+		return -EINVAL;
+
+	if (path->dentry != mnt->mnt.mnt_root)
+		return -EINVAL;
+
+	if (!can_change_locked_flags(mnt, mnt_flags))
+		return -EPERM;
+
+	down_write(&sb->s_umount);
+	ret = change_mount_ro_state(mnt, mnt_flags);
+	if (ret == 0)
+		set_mount_attributes(mnt, mnt_flags);
+	up_write(&sb->s_umount);
+	return ret;
 }
 
 /*
@@ -2243,6 +2311,7 @@ static int do_remount(struct path *path, int ms_flags, int sb_flags,
 	int err;
 	struct super_block *sb = path->mnt->mnt_sb;
 	struct mount *mnt = real_mount(path->mnt);
+	void *sec_opts = NULL;
 
 	if (!check_mnt(mnt))
 		return -EINVAL;
@@ -2250,50 +2319,25 @@ static int do_remount(struct path *path, int ms_flags, int sb_flags,
 	if (path->dentry != path->mnt->mnt_root)
 		return -EINVAL;
 
-	/* Don't allow changing of locked mnt flags.
-	 *
-	 * No locks need to be held here while testing the various
-	 * MNT_LOCK flags because those flags can never be cleared
-	 * once they are set.
-	 */
-	if ((mnt->mnt.mnt_flags & MNT_LOCK_READONLY) &&
-	    !(mnt_flags & MNT_READONLY)) {
-		return -EPERM;
-	}
-	if ((mnt->mnt.mnt_flags & MNT_LOCK_NODEV) &&
-	    !(mnt_flags & MNT_NODEV)) {
-		return -EPERM;
-	}
-	if ((mnt->mnt.mnt_flags & MNT_LOCK_NOSUID) &&
-	    !(mnt_flags & MNT_NOSUID)) {
-		return -EPERM;
-	}
-	if ((mnt->mnt.mnt_flags & MNT_LOCK_NOEXEC) &&
-	    !(mnt_flags & MNT_NOEXEC)) {
+	if (!can_change_locked_flags(mnt, mnt_flags))
 		return -EPERM;
-	}
-	if ((mnt->mnt.mnt_flags & MNT_LOCK_ATIME) &&
-	    ((mnt->mnt.mnt_flags & MNT_ATIME_MASK) != (mnt_flags & MNT_ATIME_MASK))) {
-		return -EPERM;
-	}
 
-	err = security_sb_remount(sb, data);
+	if (data && !(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)) {
+		err = security_sb_eat_lsm_opts(data, &sec_opts);
+		if (err)
+			return err;
+	}
+	err = security_sb_remount(sb, sec_opts);
+	security_free_mnt_opts(&sec_opts);
 	if (err)
 		return err;
 
 	down_write(&sb->s_umount);
-	if (ms_flags & MS_BIND)
-		err = change_mount_flags(path->mnt, ms_flags);
-	else if (!ns_capable(sb->s_user_ns, CAP_SYS_ADMIN))
 	err = -EPERM;
-	else
+	if (ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) {
 		err = do_remount_sb(sb, sb_flags, data, 0);
-	if (!err) {
-		lock_mount_hash();
-		mnt_flags |= mnt->mnt.mnt_flags & ~MNT_USER_SETTABLE_MASK;
-		mnt->mnt.mnt_flags = mnt_flags;
-		touch_mnt_namespace(mnt->mnt_ns);
-		unlock_mount_hash();
+		if (!err)
+			set_mount_attributes(mnt, mnt_flags);
 	}
 	up_write(&sb->s_umount);
 	return err;
@@ -2788,7 +2832,9 @@ long do_mount(const char *dev_name, const char __user *dir_name,
 			    SB_LAZYTIME |
 			    SB_I_VERSION);
 
-	if (flags & MS_REMOUNT)
+	if ((flags & (MS_REMOUNT | MS_BIND)) == (MS_REMOUNT | MS_BIND))
+		retval = do_reconfigure_mnt(&path, mnt_flags);
+	else if (flags & MS_REMOUNT)
 		retval = do_remount(&path, flags, sb_flags, mnt_flags,
 				    data_page);
 	else if (flags & MS_BIND)

fs/nfs/internal.h

@@ -123,7 +123,7 @@ struct nfs_parsed_mount_data {
 		unsigned short		protocol;
 	} nfs_server;
 
-	struct security_mnt_opts lsm_opts;
+	void			*lsm_opts;
 	struct net		*net;
 };
 

fs/nfs/super.c

@@ -929,7 +929,7 @@ static struct nfs_parsed_mount_data *nfs_alloc_parsed_mount_data(void)
 		data->minorversion	= 0;
 		data->need_mount	= true;
 		data->net		= current->nsproxy->net_ns;
-		security_init_mnt_opts(&data->lsm_opts);
+		data->lsm_opts		= NULL;
 	}
 	return data;
 }
@@ -1206,7 +1206,7 @@ static int nfs_get_option_ul_bound(substring_t args[], unsigned long *option,
 static int nfs_parse_mount_options(char *raw,
 				   struct nfs_parsed_mount_data *mnt)
 {
-	char *p, *string, *secdata;
+	char *p, *string;
 	int rc, sloppy = 0, invalid_option = 0;
 	unsigned short protofamily = AF_UNSPEC;
 	unsigned short mountfamily = AF_UNSPEC;
@@ -1217,20 +1217,10 @@ static int nfs_parse_mount_options(char *raw,
 	}
 	dfprintk(MOUNT, "NFS: nfs mount opts='%s'\n", raw);
 
-	secdata = alloc_secdata();
-	if (!secdata)
-		goto out_nomem;
-
-	rc = security_sb_copy_data(raw, secdata);
-	if (rc)
-		goto out_security_failure;
-
-	rc = security_sb_parse_opts_str(secdata, &mnt->lsm_opts);
+	rc = security_sb_eat_lsm_opts(raw, &mnt->lsm_opts);
 	if (rc)
 		goto out_security_failure;
 
-	free_secdata(secdata);
-
 	while ((p = strsep(&raw, ",")) != NULL) {
 		substring_t args[MAX_OPT_ARGS];
 		unsigned long option;
@@ -1682,7 +1672,6 @@ static int nfs_parse_mount_options(char *raw,
 	printk(KERN_INFO "NFS: not enough memory to parse option\n");
 	return 0;
 out_security_failure:
-	free_secdata(secdata);
 	printk(KERN_INFO "NFS: security options invalid: %d\n", rc);
 	return 0;
 }
@@ -2081,14 +2070,9 @@ static int nfs23_validate_mount_data(void *options,
 		if (data->context[0]){
 #ifdef CONFIG_SECURITY_SELINUX
 			int rc;
-			char *opts_str = kmalloc(sizeof(data->context) + 8, GFP_KERNEL);
-			if (!opts_str)
-				return -ENOMEM;
-			strcpy(opts_str, "context=");
 			data->context[NFS_MAX_CONTEXT_LEN] = '\0';
-			strcat(opts_str, &data->context[0]);
-			rc = security_sb_parse_opts_str(opts_str, &args->lsm_opts);
-			kfree(opts_str);
+			rc = security_add_mnt_opt("context", data->context,
+					strlen(data->context), &args->lsm_opts);
 			if (rc)
 				return rc;
 #else
@@ -2271,7 +2255,7 @@ nfs_remount(struct super_block *sb, int *flags, char *raw_data)
 					   options->version <= 6))))
 		return 0;
 
-	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	data = nfs_alloc_parsed_mount_data();
 	if (data == NULL)
 		return -ENOMEM;
 
@@ -2310,8 +2294,10 @@ nfs_remount(struct super_block *sb, int *flags, char *raw_data)
 
 	/* compare new mount options with old ones */
 	error = nfs_compare_remount_data(nfss, data);
+	if (!error)
+		error = security_sb_remount(sb, data->lsm_opts);
 out:
-	kfree(data);
+	nfs_free_parsed_mount_data(data);
 	return error;
 }
 EXPORT_SYMBOL_GPL(nfs_remount);
@@ -2548,7 +2534,7 @@ int nfs_set_sb_security(struct super_block *s, struct dentry *mntroot,
 	if (NFS_SB(s)->caps & NFS_CAP_SECURITY_LABEL)
 		kflags |= SECURITY_LSM_NATIVE_LABELS;
 
-	error = security_sb_set_mnt_opts(s, &mount_info->parsed->lsm_opts,
+	error = security_sb_set_mnt_opts(s, mount_info->parsed->lsm_opts,
 						kflags, &kflags_out);
 	if (error)
 		goto err;

fs/pnode.c

@@ -10,6 +10,7 @@
 #include <linux/mount.h>
 #include <linux/fs.h>
 #include <linux/nsproxy.h>
+#include <uapi/linux/mount.h>
 #include "internal.h"
 #include "pnode.h"
 

fs/super.c

@@ -35,6 +35,7 @@
 #include <linux/fsnotify.h>
 #include <linux/lockdep.h>
 #include <linux/user_namespace.h>
+#include <uapi/linux/mount.h>
 #include "internal.h"
 
 static int thaw_super_locked(struct super_block *sb);
@@ -1245,17 +1246,13 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
 {
 	struct dentry *root;
 	struct super_block *sb;
-	char *secdata = NULL;
 	int error = -ENOMEM;
+	void *sec_opts = NULL;
 
 	if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) {
-		secdata = alloc_secdata();
-		if (!secdata)
-			goto out;
-
-		error = security_sb_copy_data(data, secdata);
+		error = security_sb_eat_lsm_opts(data, &sec_opts);
 		if (error)
-			goto out_free_secdata;
+			return ERR_PTR(error);
 	}
 
 	root = type->mount(type, flags, name, data);
@@ -1276,10 +1273,16 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
 	smp_wmb();
 	sb->s_flags |= SB_BORN;
 
-	error = security_sb_kern_mount(sb, flags, secdata);
+	error = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
 	if (error)
 		goto out_sb;
 
+	if (!(flags & (MS_KERNMOUNT|MS_SUBMOUNT))) {
+		error = security_sb_kern_mount(sb);
+		if (error)
+			goto out_sb;
+	}
+
 	/*
 	 * filesystems should never set s_maxbytes larger than MAX_LFS_FILESIZE
 	 * but s_maxbytes was an unsigned long long for many releases. Throw
@@ -1290,14 +1293,13 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
 		"negative value (%lld)\n", type->name, sb->s_maxbytes);
 
 	up_write(&sb->s_umount);
-	free_secdata(secdata);
+	security_free_mnt_opts(&sec_opts);
 	return root;
 out_sb:
 	dput(root);
 	deactivate_locked_super(sb);
 out_free_secdata:
-	free_secdata(secdata);
-out:
+	security_free_mnt_opts(&sec_opts);
 	return ERR_PTR(error);
 }
 

include/linux/lsm_hooks.h

@@ -1461,9 +1461,10 @@ union security_list_options {
 
 	int (*sb_alloc_security)(struct super_block *sb);
 	void (*sb_free_security)(struct super_block *sb);
-	int (*sb_copy_data)(char *orig, char *copy);
-	int (*sb_remount)(struct super_block *sb, void *data);
-	int (*sb_kern_mount)(struct super_block *sb, int flags, void *data);
+	void (*sb_free_mnt_opts)(void *mnt_opts);
+	int (*sb_eat_lsm_opts)(char *orig, void **mnt_opts);
+	int (*sb_remount)(struct super_block *sb, void *mnt_opts);
+	int (*sb_kern_mount)(struct super_block *sb);
 	int (*sb_show_options)(struct seq_file *m, struct super_block *sb);
 	int (*sb_statfs)(struct dentry *dentry);
 	int (*sb_mount)(const char *dev_name, const struct path *path,
@@ -1471,14 +1472,15 @@ union security_list_options {
 	int (*sb_umount)(struct vfsmount *mnt, int flags);
 	int (*sb_pivotroot)(const struct path *old_path, const struct path *new_path);
 	int (*sb_set_mnt_opts)(struct super_block *sb,
-				struct security_mnt_opts *opts,
+				void *mnt_opts,
 				unsigned long kern_flags,
 				unsigned long *set_kern_flags);
 	int (*sb_clone_mnt_opts)(const struct super_block *oldsb,
 					struct super_block *newsb,
 					unsigned long kern_flags,
 					unsigned long *set_kern_flags);
-	int (*sb_parse_opts_str)(char *options, struct security_mnt_opts *opts);
+	int (*sb_add_mnt_opt)(const char *option, const char *val, int len,
+			      void **mnt_opts);
 	int (*dentry_init_security)(struct dentry *dentry, int mode,
 					const struct qstr *name, void **ctx,
 					u32 *ctxlen);
@@ -1800,7 +1802,8 @@ struct security_hook_heads {
 	struct hlist_head bprm_committed_creds;
 	struct hlist_head sb_alloc_security;
 	struct hlist_head sb_free_security;
-	struct hlist_head sb_copy_data;
+	struct hlist_head sb_free_mnt_opts;
+	struct hlist_head sb_eat_lsm_opts;
 	struct hlist_head sb_remount;
 	struct hlist_head sb_kern_mount;
 	struct hlist_head sb_show_options;
@@ -1810,7 +1813,7 @@ struct security_hook_heads {
 	struct hlist_head sb_pivotroot;
 	struct hlist_head sb_set_mnt_opts;
 	struct hlist_head sb_clone_mnt_opts;
-	struct hlist_head sb_parse_opts_str;
+	struct hlist_head sb_add_mnt_opt;
 	struct hlist_head dentry_init_security;
 	struct hlist_head dentry_create_files_as;
 #ifdef CONFIG_SECURITY_PATH

include/linux/mount.h

@@ -81,7 +81,7 @@ extern void mnt_drop_write_file(struct file *file);
 extern void mntput(struct vfsmount *mnt);
 extern struct vfsmount *mntget(struct vfsmount *mnt);
 extern struct vfsmount *mnt_clone_internal(const struct path *path);
-extern int __mnt_is_readonly(struct vfsmount *mnt);
+extern bool __mnt_is_readonly(struct vfsmount *mnt);
 extern bool mnt_may_suid(struct vfsmount *mnt);
 
 struct path;

include/linux/security.h

@@ -182,36 +182,10 @@ static inline const char *kernel_load_data_id_str(enum kernel_load_data_id id)
 
 #ifdef CONFIG_SECURITY
 
-struct security_mnt_opts {
-	char **mnt_opts;
-	int *mnt_opts_flags;
-	int num_mnt_opts;
-};
-
 int call_lsm_notifier(enum lsm_event event, void *data);
 int register_lsm_notifier(struct notifier_block *nb);
 int unregister_lsm_notifier(struct notifier_block *nb);
 
-static inline void security_init_mnt_opts(struct security_mnt_opts *opts)
-{
-	opts->mnt_opts = NULL;
-	opts->mnt_opts_flags = NULL;
-	opts->num_mnt_opts = 0;
-}
-
-static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
-{
-	int i;
-	if (opts->mnt_opts)
-		for (i = 0; i < opts->num_mnt_opts; i++)
-			kfree(opts->mnt_opts[i]);
-	kfree(opts->mnt_opts);
-	opts->mnt_opts = NULL;
-	kfree(opts->mnt_opts_flags);
-	opts->mnt_opts_flags = NULL;
-	opts->num_mnt_opts = 0;
-}
-
 /* prototypes */
 extern int security_init(void);
 
@@ -248,9 +222,10 @@ void security_bprm_committing_creds(struct linux_binprm *bprm);
 void security_bprm_committed_creds(struct linux_binprm *bprm);
 int security_sb_alloc(struct super_block *sb);
 void security_sb_free(struct super_block *sb);
-int security_sb_copy_data(char *orig, char *copy);
-int security_sb_remount(struct super_block *sb, void *data);
-int security_sb_kern_mount(struct super_block *sb, int flags, void *data);
+void security_free_mnt_opts(void **mnt_opts);
+int security_sb_eat_lsm_opts(char *options, void **mnt_opts);
+int security_sb_remount(struct super_block *sb, void *mnt_opts);
+int security_sb_kern_mount(struct super_block *sb);
 int security_sb_show_options(struct seq_file *m, struct super_block *sb);
 int security_sb_statfs(struct dentry *dentry);
 int security_sb_mount(const char *dev_name, const struct path *path,
@@ -258,14 +233,15 @@ int security_sb_mount(const char *dev_name, const struct path *path,
 int security_sb_umount(struct vfsmount *mnt, int flags);
 int security_sb_pivotroot(const struct path *old_path, const struct path *new_path);
 int security_sb_set_mnt_opts(struct super_block *sb,
-				struct security_mnt_opts *opts,
+				void *mnt_opts,
 				unsigned long kern_flags,
 				unsigned long *set_kern_flags);
 int security_sb_clone_mnt_opts(const struct super_block *oldsb,
 				struct super_block *newsb,
 				unsigned long kern_flags,
 				unsigned long *set_kern_flags);
-int security_sb_parse_opts_str(char *options, struct security_mnt_opts *opts);
+int security_add_mnt_opt(const char *option, const char *val,
+				int len, void **mnt_opts);
 int security_dentry_init_security(struct dentry *dentry, int mode,
 					const struct qstr *name, void **ctx,
 					u32 *ctxlen);
@@ -403,8 +379,6 @@ int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
 int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
 int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
 #else /* CONFIG_SECURITY */
-struct security_mnt_opts {
-};
 
 static inline int call_lsm_notifier(enum lsm_event event, void *data)
 {
@@ -421,11 +395,7 @@ static inline  int unregister_lsm_notifier(struct notifier_block *nb)
 	return 0;
 }
 
-static inline void security_init_mnt_opts(struct security_mnt_opts *opts)
-{
-}
-
-static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
+static inline void security_free_mnt_opts(void **mnt_opts)
 {
 }
 
@@ -555,17 +525,19 @@ static inline int security_sb_alloc(struct super_block *sb)
 static inline void security_sb_free(struct super_block *sb)
 { }
 
-static inline int security_sb_copy_data(char *orig, char *copy)
+static inline int security_sb_eat_lsm_opts(char *options,
+					   void **mnt_opts)
 {
 	return 0;
 }
 
-static inline int security_sb_remount(struct super_block *sb, void *data)
+static inline int security_sb_remount(struct super_block *sb,
+				      void *mnt_opts)
 {
 	return 0;
 }
 
-static inline int security_sb_kern_mount(struct super_block *sb, int flags, void *data)
+static inline int security_sb_kern_mount(struct super_block *sb)
 {
 	return 0;
 }
@@ -600,7 +572,7 @@ static inline int security_sb_pivotroot(const struct path *old_path,
 }
 
 static inline int security_sb_set_mnt_opts(struct super_block *sb,
-					   struct security_mnt_opts *opts,
+					   void *mnt_opts,
 					   unsigned long kern_flags,
 					   unsigned long *set_kern_flags)
 {
@@ -615,7 +587,8 @@ static inline int security_sb_clone_mnt_opts(const struct super_block *oldsb,
 	return 0;
 }
 
-static inline int security_sb_parse_opts_str(char *options, struct security_mnt_opts *opts)
+static inline int security_add_mnt_opt(const char *option, const char *val,
+					int len, void **mnt_opts)
 {
 	return 0;
 }
@@ -1820,28 +1793,5 @@ static inline void security_bpf_prog_free(struct bpf_prog_aux *aux)
 #endif /* CONFIG_SECURITY */
 #endif /* CONFIG_BPF_SYSCALL */
 
-#ifdef CONFIG_SECURITY
-
-static inline char *alloc_secdata(void)
-{
-	return (char *)get_zeroed_page(GFP_KERNEL);
-}
-
-static inline void free_secdata(void *secdata)
-{
-	free_page((unsigned long)secdata);
-}
-
-#else
-
-static inline char *alloc_secdata(void)
-{
-        return (char *)1;
-}
-
-static inline void free_secdata(void *secdata)
-{ }
-#endif /* CONFIG_SECURITY */
-
 #endif /* ! __LINUX_SECURITY_H */
 

include/uapi/linux/fs.h

@@ -14,6 +14,11 @@
 #include <linux/ioctl.h>
 #include <linux/types.h>
 
+/* Use of MS_* flags within the kernel is restricted to core mount(2) code. */
+#if !defined(__KERNEL__)
+#include <linux/mount.h>
+#endif
+
 /*
  * It's silly to have NR_OPEN bigger than NR_FILE, but you can change
  * the file limit at runtime and only root can increase the per-process
@@ -101,57 +106,6 @@ struct inodes_stat_t {
 
 #define NR_FILE  8192	/* this can well be larger on a larger system */
 
-
-/*
- * These are the fs-independent mount-flags: up to 32 flags are supported
- */
-#define MS_RDONLY	 1	/* Mount read-only */
-#define MS_NOSUID	 2	/* Ignore suid and sgid bits */
-#define MS_NODEV	 4	/* Disallow access to device special files */
-#define MS_NOEXEC	 8	/* Disallow program execution */
-#define MS_SYNCHRONOUS	16	/* Writes are synced at once */
-#define MS_REMOUNT	32	/* Alter flags of a mounted FS */
-#define MS_MANDLOCK	64	/* Allow mandatory locks on an FS */
-#define MS_DIRSYNC	128	/* Directory modifications are synchronous */
-#define MS_NOATIME	1024	/* Do not update access times. */
-#define MS_NODIRATIME	2048	/* Do not update directory access times */
-#define MS_BIND		4096
-#define MS_MOVE		8192
-#define MS_REC		16384
-#define MS_VERBOSE	32768	/* War is peace. Verbosity is silence.
-				   MS_VERBOSE is deprecated. */
-#define MS_SILENT	32768
-#define MS_POSIXACL	(1<<16)	/* VFS does not apply the umask */
-#define MS_UNBINDABLE	(1<<17)	/* change to unbindable */
-#define MS_PRIVATE	(1<<18)	/* change to private */
-#define MS_SLAVE	(1<<19)	/* change to slave */
-#define MS_SHARED	(1<<20)	/* change to shared */
-#define MS_RELATIME	(1<<21)	/* Update atime relative to mtime/ctime. */
-#define MS_KERNMOUNT	(1<<22) /* this is a kern_mount call */
-#define MS_I_VERSION	(1<<23) /* Update inode I_version field */
-#define MS_STRICTATIME	(1<<24) /* Always perform atime updates */
-#define MS_LAZYTIME	(1<<25) /* Update the on-disk [acm]times lazily */
-
-/* These sb flags are internal to the kernel */
-#define MS_SUBMOUNT     (1<<26)
-#define MS_NOREMOTELOCK	(1<<27)
-#define MS_NOSEC	(1<<28)
-#define MS_BORN		(1<<29)
-#define MS_ACTIVE	(1<<30)
-#define MS_NOUSER	(1<<31)
-
-/*
- * Superblock flags that can be altered by MS_REMOUNT
- */
-#define MS_RMT_MASK	(MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION|\
-			 MS_LAZYTIME)
-
-/*
- * Old magic mount flag and mask
- */
-#define MS_MGC_VAL 0xC0ED0000
-#define MS_MGC_MSK 0xffff0000
-
 /*
  * Structure for FS_IOC_FSGETXATTR[A] and FS_IOC_FSSETXATTR.
  */

include/uapi/linux/mount.h

+#ifndef _UAPI_LINUX_MOUNT_H
+#define _UAPI_LINUX_MOUNT_H
+
+/*
+ * These are the fs-independent mount-flags: up to 32 flags are supported
+ *
+ * Usage of these is restricted within the kernel to core mount(2) code and
+ * callers of sys_mount() only.  Filesystems should be using the SB_*
+ * equivalent instead.
+ */
+#define MS_RDONLY	 1	/* Mount read-only */
+#define MS_NOSUID	 2	/* Ignore suid and sgid bits */
+#define MS_NODEV	 4	/* Disallow access to device special files */
+#define MS_NOEXEC	 8	/* Disallow program execution */
+#define MS_SYNCHRONOUS	16	/* Writes are synced at once */
+#define MS_REMOUNT	32	/* Alter flags of a mounted FS */
+#define MS_MANDLOCK	64	/* Allow mandatory locks on an FS */
+#define MS_DIRSYNC	128	/* Directory modifications are synchronous */
+#define MS_NOATIME	1024	/* Do not update access times. */
+#define MS_NODIRATIME	2048	/* Do not update directory access times */
+#define MS_BIND		4096
+#define MS_MOVE		8192
+#define MS_REC		16384
+#define MS_VERBOSE	32768	/* War is peace. Verbosity is silence.
+				   MS_VERBOSE is deprecated. */
+#define MS_SILENT	32768
+#define MS_POSIXACL	(1<<16)	/* VFS does not apply the umask */
+#define MS_UNBINDABLE	(1<<17)	/* change to unbindable */
+#define MS_PRIVATE	(1<<18)	/* change to private */
+#define MS_SLAVE	(1<<19)	/* change to slave */
+#define MS_SHARED	(1<<20)	/* change to shared */
+#define MS_RELATIME	(1<<21)	/* Update atime relative to mtime/ctime. */
+#define MS_KERNMOUNT	(1<<22) /* this is a kern_mount call */
+#define MS_I_VERSION	(1<<23) /* Update inode I_version field */
+#define MS_STRICTATIME	(1<<24) /* Always perform atime updates */
+#define MS_LAZYTIME	(1<<25) /* Update the on-disk [acm]times lazily */
+
+/* These sb flags are internal to the kernel */
+#define MS_SUBMOUNT     (1<<26)
+#define MS_NOREMOTELOCK	(1<<27)
+#define MS_NOSEC	(1<<28)
+#define MS_BORN		(1<<29)
+#define MS_ACTIVE	(1<<30)
+#define MS_NOUSER	(1<<31)
+
+/*
+ * Superblock flags that can be altered by MS_REMOUNT
+ */
+#define MS_RMT_MASK	(MS_RDONLY|MS_SYNCHRONOUS|MS_MANDLOCK|MS_I_VERSION|\
+			 MS_LAZYTIME)
+
+/*
+ * Old magic mount flag and mask
+ */
+#define MS_MGC_VAL 0xC0ED0000
+#define MS_MGC_MSK 0xffff0000
+
+#endif /* _UAPI_LINUX_MOUNT_H */

init/do_mounts.c

@@ -22,6 +22,7 @@
 #include <linux/nfs_fs.h>
 #include <linux/nfs_fs_sb.h>
 #include <linux/nfs_mount.h>
+#include <uapi/linux/mount.h>
 
 #include "do_mounts.h"
 

init/do_mounts_initrd.c

@@ -8,6 +8,7 @@
 #include <linux/sched.h>
 #include <linux/freezer.h>
 #include <linux/kmod.h>
+#include <uapi/linux/mount.h>
 
 #include "do_mounts.h"
 

security/apparmor/lsm.c

@@ -26,6 +26,7 @@
 #include <linux/netfilter_ipv4.h>
 #include <linux/netfilter_ipv6.h>
 #include <net/sock.h>
+#include <uapi/linux/mount.h>
 
 #include "include/apparmor.h"
 #include "include/apparmorfs.h"

security/apparmor/mount.c

@@ -15,6 +15,7 @@
 #include <linux/fs.h>
 #include <linux/mount.h>
 #include <linux/namei.h>
+#include <uapi/linux/mount.h>
 
 #include "include/apparmor.h"
 #include "include/audit.h"

security/security.c

@@ -384,20 +384,31 @@ void security_sb_free(struct super_block *sb)
 	call_void_hook(sb_free_security, sb);
 }
 
-int security_sb_copy_data(char *orig, char *copy)
+void security_free_mnt_opts(void **mnt_opts)
 {
-	return call_int_hook(sb_copy_data, 0, orig, copy);
+	if (!*mnt_opts)
+		return;
+	call_void_hook(sb_free_mnt_opts, *mnt_opts);
+	*mnt_opts = NULL;
+}
+EXPORT_SYMBOL(security_free_mnt_opts);
+
+int security_sb_eat_lsm_opts(char *options, void **mnt_opts)
+{
+	return call_int_hook(sb_eat_lsm_opts, 0, options, mnt_opts);
 }
-EXPORT_SYMBOL(security_sb_copy_data);
+EXPORT_SYMBOL(security_sb_eat_lsm_opts);
 
-int security_sb_remount(struct super_block *sb, void *data)
+int security_sb_remount(struct super_block *sb,
+			void *mnt_opts)
 {
-	return call_int_hook(sb_remount, 0, sb, data);
+	return call_int_hook(sb_remount, 0, sb, mnt_opts);
 }
+EXPORT_SYMBOL(security_sb_remount);
 
-int security_sb_kern_mount(struct super_block *sb, int flags, void *data)
+int security_sb_kern_mount(struct super_block *sb)
 {
-	return call_int_hook(sb_kern_mount, 0, sb, flags, data);
+	return call_int_hook(sb_kern_mount, 0, sb);
 }
 
 int security_sb_show_options(struct seq_file *m, struct super_block *sb)
@@ -427,13 +438,13 @@ int security_sb_pivotroot(const struct path *old_path, const struct path *new_pa
 }
 
 int security_sb_set_mnt_opts(struct super_block *sb,
-				struct security_mnt_opts *opts,
+				void *mnt_opts,
 				unsigned long kern_flags,
 				unsigned long *set_kern_flags)
 {
 	return call_int_hook(sb_set_mnt_opts,
-				opts->num_mnt_opts ? -EOPNOTSUPP : 0, sb,
-				opts, kern_flags, set_kern_flags);
+				mnt_opts ? -EOPNOTSUPP : 0, sb,
+				mnt_opts, kern_flags, set_kern_flags);
 }
 EXPORT_SYMBOL(security_sb_set_mnt_opts);
 
@@ -447,11 +458,13 @@ int security_sb_clone_mnt_opts(const struct super_block *oldsb,
 }
 EXPORT_SYMBOL(security_sb_clone_mnt_opts);
 
-int security_sb_parse_opts_str(char *options, struct security_mnt_opts *opts)
+int security_add_mnt_opt(const char *option, const char *val, int len,
+			 void **mnt_opts)
 {
-	return call_int_hook(sb_parse_opts_str, 0, options, opts);
+	return call_int_hook(sb_add_mnt_opt, -EINVAL,
+					option, val, len, mnt_opts);
 }
-EXPORT_SYMBOL(security_sb_parse_opts_str);
+EXPORT_SYMBOL(security_add_mnt_opt);
 
 int security_inode_alloc(struct inode *inode)
 {

security/tomoyo/mount.c

@@ -6,6 +6,7 @@
  */
 
 #include <linux/slab.h>
+#include <uapi/linux/mount.h>
 #include "common.h"
 
 /* String table for special mount operations. */