From f5c0c26d9008b355babb6d16f3d7c4de3bada0e7 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Sat, 17 Nov 2018 12:09:18 -0500
Subject: new helper: security_sb_eat_lsm_opts()

combination of alloc_secdata(), security_sb_copy_data(),
security_sb_parse_opt_str() and free_secdata().

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/nfs/super.c | 15 ++-------------
 1 file changed, 2 insertions(+), 13 deletions(-)

(limited to 'fs/nfs')

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index ac4b2f005778..f9c8847171e8 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -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 @@ out_nomem:
 	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;
 }
-- 
cgit v1.2.3-59-g8ed1b


From 6a0440e5b7562512c021aa1b5a706fcc545773db Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Mon, 10 Dec 2018 17:30:41 -0500
Subject: nfs_remount(): don't leak, don't ignore LSM options quietly

* if mount(2) passes something like "context=foo" with MS_REMOUNT
in flags (/sbin/mount.nfs will _not_ do that - you need to issue
the syscall manually), you'll get leaked copies for LSM options.
The reason is that instead of nfs_{alloc,free}_parsed_mount_data()
nfs_remount() uses kzalloc/kfree, which lacks the needed cleanup.

* selinux options are not changed on remount (as for any other
fs), but in case of NFS the failure is quiet - they are not compared
to what we used to have, with complaint in case of attempted changes.
Trivially fixed by converting to use of security_sb_remount().

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/nfs/super.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

(limited to 'fs/nfs')

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index f9c8847171e8..300bdd1d4a09 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2254,7 +2254,7 @@ 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;
 
@@ -2293,8 +2293,10 @@ 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);
-- 
cgit v1.2.3-59-g8ed1b


From 204cc0ccf1d49c6292aeef4c8edd1b3d10ff933c Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Thu, 13 Dec 2018 13:41:47 -0500
Subject: LSM: hide struct security_mnt_opts from any generic code

Keep void * instead, allocate on demand (in parse_str_opts, at the
moment).  Eventually both selinux and smack will be better off
with private structures with several strings in those, rather than
this "counter and two pointers to dynamically allocated arrays"
ugliness.  This commit allows to do that at leisure, without
disrupting anything outside of given module.

Changes:
	* instead of struct security_mnt_opt use an opaque pointer
initialized to NULL.
	* security_sb_eat_lsm_opts(), security_sb_parse_opts_str() and
security_free_mnt_opts() take it as var argument (i.e. as void **);
call sites are unchanged.
	* security_sb_set_mnt_opts() and security_sb_remount() take
it by value (i.e. as void *).
	* new method: ->sb_free_mnt_opts().  Takes void *, does
whatever freeing that needs to be done.
	* ->sb_set_mnt_opts() and ->sb_remount() might get NULL as
mnt_opts argument, meaning "empty".

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/btrfs/super.c           | 10 ++++-----
 fs/namespace.c             |  9 ++++----
 fs/nfs/internal.h          |  2 +-
 fs/nfs/super.c             |  6 +++---
 fs/super.c                 | 12 +++++------
 include/linux/lsm_hooks.h  | 11 +++++-----
 include/linux/security.h   | 43 +++++++++-----------------------------
 security/security.c        | 27 ++++++++++++++++--------
 security/selinux/hooks.c   | 52 +++++++++++++++++++++++++++++++++-------------
 security/smack/smack_lsm.c | 38 ++++++++++++++++++++++++++-------
 10 files changed, 118 insertions(+), 92 deletions(-)

(limited to 'fs/nfs')

diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 3b04e7735b5f..e90c4616ed6a 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1472,14 +1472,13 @@ 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 = security_sb_eat_lsm_opts(data, &new_sec_opts);
 		if (error)
@@ -1551,7 +1550,7 @@ static struct dentry *btrfs_mount_root(struct file_system_type *fs_type,
 		error = btrfs_fill_super(s, fs_devices, data);
 	}
 	if (!error)
-		error = security_sb_set_mnt_opts(s, &new_sec_opts, 0, NULL);
+		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);
@@ -1724,12 +1723,11 @@ 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 = security_sb_eat_lsm_opts(data, &new_sec_opts);
 		if (!ret)
-			ret = security_sb_remount(sb, &new_sec_opts);
+			ret = security_sb_remount(sb, new_sec_opts);
 		security_free_mnt_opts(&new_sec_opts);
 		if (ret)
 			goto restore;
diff --git a/fs/namespace.c b/fs/namespace.c
index 39aca7b69c2e..badfd287358c 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2299,7 +2299,7 @@ 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);
-	struct security_mnt_opts opts;
+	void *sec_opts = NULL;
 
 	if (!check_mnt(mnt))
 		return -EINVAL;
@@ -2310,14 +2310,13 @@ static int do_remount(struct path *path, int ms_flags, int sb_flags,
 	if (!can_change_locked_flags(mnt, mnt_flags))
 		return -EPERM;
 
-	security_init_mnt_opts(&opts);
 	if (data && !(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)) {
-		err = security_sb_eat_lsm_opts(data, &opts);
+		err = security_sb_eat_lsm_opts(data, &sec_opts);
 		if (err)
 			return err;
 	}
-	err = security_sb_remount(sb, &opts);
-	security_free_mnt_opts(&opts);
+	err = security_sb_remount(sb, sec_opts);
+	security_free_mnt_opts(&sec_opts);
 	if (err)
 		return err;
 
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 8357ff69962f..97e1dcefe561 100644
--- a/fs/nfs/internal.h
+++ b/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;
 };
 
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 300bdd1d4a09..1943de8f9d29 100644
--- a/fs/nfs/super.c
+++ b/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;
 }
@@ -2294,7 +2294,7 @@ 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);
+		error = security_sb_remount(sb, data->lsm_opts);
 out:
 	nfs_free_parsed_mount_data(data);
 	return error;
@@ -2534,7 +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;
diff --git a/fs/super.c b/fs/super.c
index 1f75fe312597..a5511c4ba69b 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -1247,12 +1247,10 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
 	struct dentry *root;
 	struct super_block *sb;
 	int error = -ENOMEM;
-	struct security_mnt_opts opts;
-
-	security_init_mnt_opts(&opts);
+	void *sec_opts = NULL;
 
 	if (data && !(type->fs_flags & FS_BINARY_MOUNTDATA)) {
-		error = security_sb_eat_lsm_opts(data, &opts);
+		error = security_sb_eat_lsm_opts(data, &sec_opts);
 		if (error)
 			return ERR_PTR(error);
 	}
@@ -1275,7 +1273,7 @@ mount_fs(struct file_system_type *type, int flags, const char *name, void *data)
 	smp_wmb();
 	sb->s_flags |= SB_BORN;
 
-	error = security_sb_set_mnt_opts(sb, &opts, 0, NULL);
+	error = security_sb_set_mnt_opts(sb, sec_opts, 0, NULL);
 	if (error)
 		goto out_sb;
 
@@ -1295,13 +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);
-	security_free_mnt_opts(&opts);
+	security_free_mnt_opts(&sec_opts);
 	return root;
 out_sb:
 	dput(root);
 	deactivate_locked_super(sb);
 out_free_secdata:
-	security_free_mnt_opts(&opts);
+	security_free_mnt_opts(&sec_opts);
 	return ERR_PTR(error);
 }
 
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index c418909c178c..a9c541f5732e 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1461,9 +1461,9 @@ union security_list_options {
 
 	int (*sb_alloc_security)(struct super_block *sb);
 	void (*sb_free_security)(struct super_block *sb);
-	int (*sb_eat_lsm_opts)(char *orig, struct security_mnt_opts *opts);
-	int (*sb_remount)(struct super_block *sb,
-			  struct security_mnt_opts *opts);
+	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);
@@ -1472,14 +1472,14 @@ 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_parse_opts_str)(char *options, void **mnt_opts);
 	int (*dentry_init_security)(struct dentry *dentry, int mode,
 					const struct qstr *name, void **ctx,
 					u32 *ctxlen);
@@ -1801,6 +1801,7 @@ 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_free_mnt_opts;
 	struct hlist_head sb_eat_lsm_opts;
 	struct hlist_head sb_remount;
 	struct hlist_head sb_kern_mount;
diff --git a/include/linux/security.h b/include/linux/security.h
index d00093363570..4bca0be95b7a 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -192,26 +192,6 @@ 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);
 
@@ -248,8 +228,9 @@ 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_eat_lsm_opts(char *options, struct security_mnt_opts *opts);
-int security_sb_remount(struct super_block *sb, struct security_mnt_opts *opts);
+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);
@@ -258,14 +239,14 @@ 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_sb_parse_opts_str(char *options, void **mnt_opts);
 int security_dentry_init_security(struct dentry *dentry, int mode,
 					const struct qstr *name, void **ctx,
 					u32 *ctxlen);
@@ -421,11 +402,7 @@ 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)
 {
 }
 
@@ -556,13 +533,13 @@ static inline void security_sb_free(struct super_block *sb)
 { }
 
 static inline int security_sb_eat_lsm_opts(char *options,
-					   struct security_mnt_opts *opts)
+					   void **mnt_opts)
 {
 	return 0;
 }
 
 static inline int security_sb_remount(struct super_block *sb,
-				      struct security_mnt_opts *opts)
+				      void *mnt_opts)
 {
 	return 0;
 }
@@ -602,7 +579,7 @@ 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)
 {
@@ -617,7 +594,7 @@ 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_sb_parse_opts_str(char *options, void **mnt_opts)
 {
 	return 0;
 }
diff --git a/security/security.c b/security/security.c
index feb18c925349..b7a5a0051807 100644
--- a/security/security.c
+++ b/security/security.c
@@ -384,16 +384,25 @@ void security_sb_free(struct super_block *sb)
 	call_void_hook(sb_free_security, sb);
 }
 
-int security_sb_eat_lsm_opts(char *options, struct security_mnt_opts *opts)
+void security_free_mnt_opts(void **mnt_opts)
 {
-	return call_int_hook(sb_eat_lsm_opts, 0, options, opts);
+	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_eat_lsm_opts);
 
 int security_sb_remount(struct super_block *sb,
-			struct security_mnt_opts *opts)
+			void *mnt_opts)
 {
-	return call_int_hook(sb_remount, 0, sb, opts);
+	return call_int_hook(sb_remount, 0, sb, mnt_opts);
 }
 EXPORT_SYMBOL(security_sb_remount);
 
@@ -429,13 +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);
 
@@ -449,9 +458,9 @@ 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_sb_parse_opts_str(char *options, void **mnt_opts)
 {
-	return call_int_hook(sb_parse_opts_str, 0, options, opts);
+	return call_int_hook(sb_parse_opts_str, 0, options, mnt_opts);
 }
 EXPORT_SYMBOL(security_sb_parse_opts_str);
 
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 11cf2feb27b3..caf7ca7abfc1 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -433,6 +433,19 @@ static void superblock_free_security(struct super_block *sb)
 	kfree(sbsec);
 }
 
+static void selinux_free_mnt_opts(void *mnt_opts)
+{
+	struct security_mnt_opts *opts = mnt_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);
+	kfree(opts->mnt_opts_flags);
+	kfree(opts);
+}
+
 static inline int inode_doinit(struct inode *inode)
 {
 	return inode_doinit_with_dentry(inode, NULL);
@@ -616,7 +629,7 @@ static int bad_option(struct superblock_security_struct *sbsec, char flag,
  * labeling information.
  */
 static int selinux_set_mnt_opts(struct super_block *sb,
-				struct security_mnt_opts *opts,
+				void *mnt_opts,
 				unsigned long kern_flags,
 				unsigned long *set_kern_flags)
 {
@@ -628,9 +641,10 @@ static int selinux_set_mnt_opts(struct super_block *sb,
 	struct inode_security_struct *root_isec;
 	u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
 	u32 defcontext_sid = 0;
-	char **mount_options = opts->mnt_opts;
-	int *flags = opts->mnt_opts_flags;
-	int num_opts = opts->num_mnt_opts;
+	struct security_mnt_opts *opts = mnt_opts;
+	char **mount_options = opts ? opts->mnt_opts : NULL;
+	int *flags = opts ? opts->mnt_opts_flags : NULL;
+	int num_opts = opts ? opts->num_mnt_opts : 0;
 
 	mutex_lock(&sbsec->lock);
 
@@ -982,12 +996,20 @@ out:
 }
 
 static int selinux_parse_opts_str(char *options,
-				  struct security_mnt_opts *opts)
+				  void **mnt_opts)
 {
 	char *p;
 	char *context = NULL, *defcontext = NULL;
 	char *fscontext = NULL, *rootcontext = NULL;
 	int rc, num_mnt_opts = 0;
+	struct security_mnt_opts *opts = *mnt_opts;
+
+	if (!opts) {
+		opts = kzalloc(sizeof(struct security_mnt_opts), GFP_KERNEL);
+		*mnt_opts = opts;
+		if (!opts)
+			return -ENOMEM;
+	}
 
 	opts->num_mnt_opts = 0;
 
@@ -1094,7 +1116,7 @@ static int selinux_parse_opts_str(char *options,
 	return 0;
 
 out_err:
-	security_free_mnt_opts(opts);
+	security_free_mnt_opts(mnt_opts);
 	kfree(context);
 	kfree(defcontext);
 	kfree(fscontext);
@@ -2714,7 +2736,7 @@ out:
 	return rc;
 }
 
-static int selinux_sb_eat_lsm_opts(char *options, struct security_mnt_opts *opts)
+static int selinux_sb_eat_lsm_opts(char *options, void **mnt_opts)
 {
 	char *s = (char *)get_zeroed_page(GFP_KERNEL);
 	int err;
@@ -2723,14 +2745,14 @@ static int selinux_sb_eat_lsm_opts(char *options, struct security_mnt_opts *opts
 		return -ENOMEM;
 	err = selinux_sb_copy_data(options, s);
 	if (!err)
-		err = selinux_parse_opts_str(s, opts);
+		err = selinux_parse_opts_str(s, mnt_opts);
 	free_page((unsigned long)s);
 	return err;
 }
 
-static int selinux_sb_remount(struct super_block *sb,
-			      struct security_mnt_opts *opts)
+static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
 {
+	struct security_mnt_opts *opts = mnt_opts;
 	int i, *flags;
 	char **mount_options;
 	struct superblock_security_struct *sbsec = sb->s_security;
@@ -2738,6 +2760,9 @@ static int selinux_sb_remount(struct super_block *sb,
 	if (!(sbsec->flags & SE_SBINITIALIZED))
 		return 0;
 
+	if (!opts)
+		return 0;
+
 	mount_options = opts->mnt_opts;
 	flags = opts->mnt_opts_flags;
 
@@ -6782,6 +6807,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(sb_alloc_security, selinux_sb_alloc_security),
 	LSM_HOOK_INIT(sb_free_security, selinux_sb_free_security),
 	LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
+	LSM_HOOK_INIT(sb_free_mnt_opts, selinux_free_mnt_opts),
 	LSM_HOOK_INIT(sb_remount, selinux_sb_remount),
 	LSM_HOOK_INIT(sb_kern_mount, selinux_sb_kern_mount),
 	LSM_HOOK_INIT(sb_show_options, selinux_sb_show_options),
@@ -7051,11 +7077,7 @@ static __init int selinux_init(void)
 
 static void delayed_superblock_init(struct super_block *sb, void *unused)
 {
-	struct security_mnt_opts opts;
-
-	security_init_mnt_opts(&opts);
-	selinux_set_mnt_opts(sb, &opts, 0, NULL);
-	security_free_mnt_opts(&opts);
+	selinux_set_mnt_opts(sb, NULL, 0, NULL);
 }
 
 void selinux_complete_init(void)
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 835cca277c2a..81a8112975d4 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -567,6 +567,19 @@ static void smack_sb_free_security(struct super_block *sb)
 	sb->s_security = NULL;
 }
 
+static void smack_free_mnt_opts(void *mnt_opts)
+{
+	struct security_mnt_opts *opts = mnt_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);
+	kfree(opts->mnt_opts_flags);
+	kfree(opts);
+}
+
 /**
  * smack_sb_copy_data - copy mount options data for processing
  * @orig: where to start
@@ -624,8 +637,9 @@ static int smack_sb_copy_data(char *orig, char *smackopts)
  * converts Smack specific mount options to generic security option format
  */
 static int smack_parse_opts_str(char *options,
-		struct security_mnt_opts *opts)
+		void **mnt_opts)
 {
+	struct security_mnt_opts *opts = *mnt_opts;
 	char *p;
 	char *fsdefault = NULL;
 	char *fsfloor = NULL;
@@ -636,11 +650,17 @@ static int smack_parse_opts_str(char *options,
 	int num_mnt_opts = 0;
 	int token;
 
-	opts->num_mnt_opts = 0;
-
 	if (!options)
 		return 0;
 
+	if (!opts) {
+		opts = kzalloc(sizeof(struct security_mnt_opts), GFP_KERNEL);
+		*mnt_opts = opts;
+		if (!opts)
+			return -ENOMEM;
+	}
+	opts->num_mnt_opts = 0;
+
 	while ((p = strsep(&options, ",")) != NULL) {
 		substring_t args[MAX_OPT_ARGS];
 
@@ -735,11 +755,11 @@ out_err:
 	kfree(fshat);
 	kfree(fsroot);
 	kfree(fstransmute);
-	security_free_mnt_opts(opts);
+	security_free_mnt_opts(mnt_opts);
 	return rc;
 }
 
-static int smack_sb_eat_lsm_opts(char *options, struct security_mnt_opts *opts)
+static int smack_sb_eat_lsm_opts(char *options, void **mnt_opts)
 {
 	char *s = (char *)get_zeroed_page(GFP_KERNEL);
 	int err;
@@ -748,7 +768,7 @@ static int smack_sb_eat_lsm_opts(char *options, struct security_mnt_opts *opts)
 		return -ENOMEM;
 	err = smack_sb_copy_data(options, s);
 	if (!err)
-		err = smack_parse_opts_str(s, opts);
+		err = smack_parse_opts_str(s, mnt_opts);
 	free_page((unsigned long)s);
 	return err;
 }
@@ -766,7 +786,7 @@ static int smack_sb_eat_lsm_opts(char *options, struct security_mnt_opts *opts)
  * labels.
  */
 static int smack_set_mnt_opts(struct super_block *sb,
-		struct security_mnt_opts *opts,
+		void *mnt_opts,
 		unsigned long kern_flags,
 		unsigned long *set_kern_flags)
 {
@@ -776,7 +796,8 @@ static int smack_set_mnt_opts(struct super_block *sb,
 	struct inode_smack *isp;
 	struct smack_known *skp;
 	int i;
-	int num_opts = opts->num_mnt_opts;
+	struct security_mnt_opts *opts = mnt_opts;
+	int num_opts = opts ? opts->num_mnt_opts : 0;
 	int transmute = 0;
 
 	if (sp->smk_flags & SMK_SB_INITIALIZED)
@@ -4651,6 +4672,7 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
 
 	LSM_HOOK_INIT(sb_alloc_security, smack_sb_alloc_security),
 	LSM_HOOK_INIT(sb_free_security, smack_sb_free_security),
+	LSM_HOOK_INIT(sb_free_mnt_opts, smack_free_mnt_opts),
 	LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
 	LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
 	LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts),
-- 
cgit v1.2.3-59-g8ed1b


From 757cbe597fe8490c7c0a9650ebe5d60195f151d4 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Fri, 14 Dec 2018 23:42:21 -0500
Subject: LSM: new method: ->sb_add_mnt_opt()

Adding options to growing mnt_opts.  NFS kludge with passing
context= down into non-text-options mount switched to it, and
with that the last use of ->sb_parse_opts_str() is gone.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 fs/nfs/super.c             |  9 ++-------
 include/linux/lsm_hooks.h  |  5 +++--
 include/linux/security.h   |  6 ++++--
 security/security.c        |  8 +++++---
 security/selinux/hooks.c   | 45 +++++++++++++++++++--------------------------
 security/smack/smack_lsm.c |  1 -
 6 files changed, 33 insertions(+), 41 deletions(-)

(limited to 'fs/nfs')

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 1943de8f9d29..073eec2366f8 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -2070,14 +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
diff --git a/include/linux/lsm_hooks.h b/include/linux/lsm_hooks.h
index a9c541f5732e..9a0bdf91e646 100644
--- a/include/linux/lsm_hooks.h
+++ b/include/linux/lsm_hooks.h
@@ -1479,7 +1479,8 @@ union security_list_options {
 					struct super_block *newsb,
 					unsigned long kern_flags,
 					unsigned long *set_kern_flags);
-	int (*sb_parse_opts_str)(char *options, void **mnt_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);
@@ -1812,7 +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
diff --git a/include/linux/security.h b/include/linux/security.h
index ae8d5ac5882e..dbfb5a66babb 100644
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -240,7 +240,8 @@ 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, void **mnt_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);
@@ -586,7 +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, void **mnt_opts)
+static inline int security_add_mnt_opt(const char *option, const char *val,
+					int len, void **mnt_opts)
 {
 	return 0;
 }
diff --git a/security/security.c b/security/security.c
index b7a5a0051807..c251278b0297 100644
--- a/security/security.c
+++ b/security/security.c
@@ -458,11 +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, void **mnt_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, mnt_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)
 {
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 5336d6671c5c..5bc230327bc0 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1049,40 +1049,33 @@ Einval:
 	return -EINVAL;
 }
 
-static int selinux_parse_opts_str(char *options,
-				  void **mnt_opts)
+static int selinux_add_mnt_opt(const char *option, const char *val, int len,
+			       void **mnt_opts)
 {
-	char *p = options, *next;
-	int rc;
-
-	/* Standard string-based options. */
-	for (p = options; *p; p = next) {
-		int token, len;
-		char *arg = NULL;
+	int token = Opt_error;
+	int rc, i;
 
-		next = strchr(p, '|');
-		if (next) {
-			len = next++ - p;
-		} else {
-			len = strlen(p);
-			next = p + len;
+	for (i = 0; i < ARRAY_SIZE(tokens); i++) {
+		if (strcmp(option, tokens[i].name) == 0) {
+			token = tokens[i].opt;
+			break;
 		}
+	}
 
-		if (!len)
-			continue;
+	if (token == Opt_error)
+		return -EINVAL;
 
-		token = match_opt_prefix(p, len, &arg);
-		if (arg)
-			arg = kmemdup_nul(arg, p + len - arg, GFP_KERNEL);
-		rc = selinux_add_opt(token, arg, mnt_opts);
-		if (rc) {
-			kfree(arg);
+	if (token != Opt_seclabel)
+		val = kmemdup_nul(val, len, GFP_KERNEL);
+	rc = selinux_add_opt(token, val, mnt_opts);
+	if (unlikely(rc)) {
+		kfree(val);
+		if (*mnt_opts) {
 			selinux_free_mnt_opts(*mnt_opts);
 			*mnt_opts = NULL;
-			return rc;
 		}
 	}
-	return 0;
+	return rc;
 }
 
 static int show_sid(struct seq_file *m, u32 sid)
@@ -6726,7 +6719,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(sb_umount, selinux_umount),
 	LSM_HOOK_INIT(sb_set_mnt_opts, selinux_set_mnt_opts),
 	LSM_HOOK_INIT(sb_clone_mnt_opts, selinux_sb_clone_mnt_opts),
-	LSM_HOOK_INIT(sb_parse_opts_str, selinux_parse_opts_str),
+	LSM_HOOK_INIT(sb_add_mnt_opt, selinux_add_mnt_opt),
 
 	LSM_HOOK_INIT(dentry_init_security, selinux_dentry_init_security),
 	LSM_HOOK_INIT(dentry_create_files_as, selinux_dentry_create_files_as),
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 99aec9f42be3..b607b1151e30 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -4629,7 +4629,6 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
 	LSM_HOOK_INIT(sb_eat_lsm_opts, smack_sb_eat_lsm_opts),
 	LSM_HOOK_INIT(sb_statfs, smack_sb_statfs),
 	LSM_HOOK_INIT(sb_set_mnt_opts, smack_set_mnt_opts),
-	LSM_HOOK_INIT(sb_parse_opts_str, smack_parse_opts_str),
 
 	LSM_HOOK_INIT(bprm_set_creds, smack_bprm_set_creds),
 
-- 
cgit v1.2.3-59-g8ed1b