2 files changed, 219 insertions, 40 deletions

diff --git a/security/smack/smack.h b/security/smack/smack.h
index 244e035e5a99..69ab9eb7d6d9 100644
--- a/security/smack/smack.h
+++ b/security/smack/smack.h
@@ -143,6 +143,24 @@ struct smack_onlycap {
         struct smack_known      *smk_label;
 };
 
+/* Super block security struct flags for mount options */
+#define FSDEFAULT_MNT   0x01
+#define FSFLOOR_MNT     0x02
+#define FSHAT_MNT       0x04
+#define FSROOT_MNT      0x08
+#define FSTRANS_MNT     0x10
+
+#define NUM_SMK_MNT_OPTS        5
+
+enum {
+        Opt_error = -1,
+        Opt_fsdefault = 1,
+        Opt_fsfloor = 2,
+        Opt_fshat = 3,
+        Opt_fsroot = 4,
+        Opt_fstransmute = 5,
+};
+
 /*
  * Mount options
  */
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index a143328f75eb..d962f887d3f4 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -41,6 +41,7 @@
 #include <linux/msg.h>
 #include <linux/shm.h>
 #include <linux/binfmts.h>
+#include <linux/parser.h>
 #include "smack.h"
 
 #define TRANS_TRUE      "TRUE"
@@ -64,6 +65,15 @@ static char *smk_bu_mess[] = {
         "Unconfined Object",    /* SMACK_UNCONFINED_OBJECT */
 };
 
+static const match_table_t tokens = {
+        {Opt_fsdefault, SMK_FSDEFAULT "%s"},
+        {Opt_fsfloor, SMK_FSFLOOR "%s"},
+        {Opt_fshat, SMK_FSHAT "%s"},
+        {Opt_fsroot, SMK_FSROOT "%s"},
+        {Opt_fstransmute, SMK_FSTRANS "%s"},
+        {Opt_error, NULL},
+};
+
 static void smk_bu_mode(int mode, char *s)
 {
         int i = 0;
@@ -577,76 +587,193 @@ static int smack_sb_copy_data(char *orig, char *smackopts)
 }
 
 /**
- * smack_sb_kern_mount - Smack specific mount processing
+ * smack_parse_opts_str - parse Smack specific mount options
+ * @options: mount options string
+ * @opts: where to store converted mount opts
+ *
+ * Returns 0 on success or -ENOMEM on error.
+ *
+ * converts Smack specific mount options to generic security option format
+ */
+static int smack_parse_opts_str(char *options,
+                struct security_mnt_opts *opts)
+{
+        char *p;
+        char *fsdefault = NULL, *fsfloor = NULL;
+        char *fshat = NULL, *fsroot = NULL, *fstransmute = NULL;
+        int rc = -ENOMEM, num_mnt_opts = 0;
+
+        opts->num_mnt_opts = 0;
+
+        if (!options)
+                return 0;
+
+        while ((p = strsep(&options, ",")) != NULL) {
+                int token;
+                substring_t args[MAX_OPT_ARGS];
+
+                if (!*p)
+                        continue;
+
+                token = match_token(p, tokens, args);
+
+                switch (token) {
+                case Opt_fsdefault:
+                        if (fsdefault)
+                                goto out_opt_err;
+                        fsdefault = match_strdup(&args[0]);
+                        if (!fsdefault)
+                                goto out_err;
+                        break;
+                case Opt_fsfloor:
+                        if (fsfloor)
+                                goto out_opt_err;
+                        fsfloor = match_strdup(&args[0]);
+                        if (!fsfloor)
+                                goto out_err;
+                        break;
+                case Opt_fshat:
+                        if (fshat)
+                                goto out_opt_err;
+                        fshat = match_strdup(&args[0]);
+                        if (!fshat)
+                                goto out_err;
+                        break;
+                case Opt_fsroot:
+                        if (fsroot)
+                                goto out_opt_err;
+                        fsroot = match_strdup(&args[0]);
+                        if (!fsroot)
+                                goto out_err;
+                        break;
+                case Opt_fstransmute:
+                        if (fstransmute)
+                                goto out_opt_err;
+                        fstransmute = match_strdup(&args[0]);
+                        if (!fstransmute)
+                                goto out_err;
+                        break;
+                default:
+                        rc = -EINVAL;
+                        pr_warn("Smack:  unknown mount option\n");
+                        goto out_err;
+                }
+        }
+
+        opts->mnt_opts = kcalloc(NUM_SMK_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
+        if (!opts->mnt_opts)
+                goto out_err;
+
+        opts->mnt_opts_flags = kcalloc(NUM_SMK_MNT_OPTS, sizeof(int),
+                        GFP_ATOMIC);
+        if (!opts->mnt_opts_flags) {
+                kfree(opts->mnt_opts);
+                goto out_err;
+        }
+
+        if (fsdefault) {
+                opts->mnt_opts[num_mnt_opts] = fsdefault;
+                opts->mnt_opts_flags[num_mnt_opts++] = FSDEFAULT_MNT;
+        }
+        if (fsfloor) {
+                opts->mnt_opts[num_mnt_opts] = fsfloor;
+                opts->mnt_opts_flags[num_mnt_opts++] = FSFLOOR_MNT;
+        }
+        if (fshat) {
+                opts->mnt_opts[num_mnt_opts] = fshat;
+                opts->mnt_opts_flags[num_mnt_opts++] = FSHAT_MNT;
+        }
+        if (fsroot) {
+                opts->mnt_opts[num_mnt_opts] = fsroot;
+                opts->mnt_opts_flags[num_mnt_opts++] = FSROOT_MNT;
+        }
+        if (fstransmute) {
+                opts->mnt_opts[num_mnt_opts] = fstransmute;
+                opts->mnt_opts_flags[num_mnt_opts++] = FSTRANS_MNT;
+        }
+
+        opts->num_mnt_opts = num_mnt_opts;
+        return 0;
+
+out_opt_err:
+        rc = -EINVAL;
+        pr_warn("Smack: duplicate mount options\n");
+
+out_err:
+        kfree(fsdefault);
+        kfree(fsfloor);
+        kfree(fshat);
+        kfree(fsroot);
+        kfree(fstransmute);
+        return rc;
+}
+
+/**
+ * smack_set_mnt_opts - set Smack specific mount options
  * @sb: the file system superblock
- * @flags: the mount flags
- * @data: the smack mount options
+ * @opts: Smack mount options
+ * @kern_flags: mount option from kernel space or user space
+ * @set_kern_flags: where to store converted mount opts
  *
  * Returns 0 on success, an error code on failure
+ *
+ * Allow filesystems with binary mount data to explicitly set Smack mount
+ * labels.
  */
-static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
+static int smack_set_mnt_opts(struct super_block *sb,
+                struct security_mnt_opts *opts,
+                unsigned long kern_flags,
+                unsigned long *set_kern_flags)
 {
         struct dentry *root = sb->s_root;
         struct inode *inode = d_backing_inode(root);
         struct superblock_smack *sp = sb->s_security;
         struct inode_smack *isp;
         struct smack_known *skp;
-        char *op;
-        char *commap;
+        int i;
+        int num_opts = opts->num_mnt_opts;
         int transmute = 0;
-        int specified = 0;
 
         if (sp->smk_initialized)
                 return 0;
 
         sp->smk_initialized = 1;
 
-        for (op = data; op != NULL; op = commap) {
-                commap = strchr(op, ',');
-                if (commap != NULL)
-                        *commap++ = '\0';
-
-                if (strncmp(op, SMK_FSHAT, strlen(SMK_FSHAT)) == 0) {
-                        op += strlen(SMK_FSHAT);
-                        skp = smk_import_entry(op, 0);
+        for (i = 0; i < num_opts; i++) {
+                switch (opts->mnt_opts_flags[i]) {
+                case FSDEFAULT_MNT:
+                        skp = smk_import_entry(opts->mnt_opts[i], 0);
                         if (IS_ERR(skp))
                                 return PTR_ERR(skp);
-                        sp->smk_hat = skp;
-                        specified = 1;
-
-                } else if (strncmp(op, SMK_FSFLOOR, strlen(SMK_FSFLOOR)) == 0) {
-                        op += strlen(SMK_FSFLOOR);
-                        skp = smk_import_entry(op, 0);
+                        sp->smk_default = skp;
+                        break;
+                case FSFLOOR_MNT:
+                        skp = smk_import_entry(opts->mnt_opts[i], 0);
                         if (IS_ERR(skp))
                                 return PTR_ERR(skp);
                         sp->smk_floor = skp;
-                        specified = 1;
-
-                } else if (strncmp(op, SMK_FSDEFAULT,
-                                   strlen(SMK_FSDEFAULT)) == 0) {
-                        op += strlen(SMK_FSDEFAULT);
-                        skp = smk_import_entry(op, 0);
+                        break;
+                case FSHAT_MNT:
+                        skp = smk_import_entry(opts->mnt_opts[i], 0);
                         if (IS_ERR(skp))
                                 return PTR_ERR(skp);
-                        sp->smk_default = skp;
-                        specified = 1;
-
-                } else if (strncmp(op, SMK_FSROOT, strlen(SMK_FSROOT)) == 0) {
-                        op += strlen(SMK_FSROOT);
-                        skp = smk_import_entry(op, 0);
+                        sp->smk_hat = skp;
+                        break;
+                case FSROOT_MNT:
+                        skp = smk_import_entry(opts->mnt_opts[i], 0);
                         if (IS_ERR(skp))
                                 return PTR_ERR(skp);
                         sp->smk_root = skp;
-                        specified = 1;
-
-                } else if (strncmp(op, SMK_FSTRANS, strlen(SMK_FSTRANS)) == 0) {
-                        op += strlen(SMK_FSTRANS);
-                        skp = smk_import_entry(op, 0);
+                        break;
+                case FSTRANS_MNT:
+                        skp = smk_import_entry(opts->mnt_opts[i], 0);
                         if (IS_ERR(skp))
                                 return PTR_ERR(skp);
                         sp->smk_root = skp;
                         transmute = 1;
-                        specified = 1;
+                        break;
+                default:
+                        break;
                 }
         }
 
@@ -654,7 +781,7 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
                 /*
                  * Unprivileged mounts don't get to specify Smack values.
                  */
-                if (specified)
+                if (num_opts)
                         return -EPERM;
                 /*
                  * Unprivileged mounts get root and default from the caller.
@@ -663,6 +790,7 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
                 sp->smk_root = skp;
                 sp->smk_default = skp;
         }
+
         /*
          * Initialize the root inode.
          */
@@ -682,6 +810,37 @@ static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
 }
 
 /**
+ * smack_sb_kern_mount - Smack specific mount processing
+ * @sb: the file system superblock
+ * @flags: the mount flags
+ * @data: the smack mount options
+ *
+ * Returns 0 on success, an error code on failure
+ */
+static int smack_sb_kern_mount(struct super_block *sb, int flags, void *data)
+{
+        int rc = 0;
+        char *options = data;
+        struct security_mnt_opts opts;
+
+        security_init_mnt_opts(&opts);
+
+        if (!options)
+                goto out;
+
+        rc = smack_parse_opts_str(options, &opts);
+        if (rc)
+                goto out_err;
+
+out:
+        rc = smack_set_mnt_opts(sb, &opts, 0, NULL);
+
+out_err:
+        security_free_mnt_opts(&opts);
+        return rc;
+}
+
+/**
  * smack_sb_statfs - Smack check on statfs
  * @dentry: identifies the file system in question
  *
@@ -4264,6 +4423,8 @@ struct security_hook_list smack_hooks[] = {
         LSM_HOOK_INIT(sb_copy_data, smack_sb_copy_data),
         LSM_HOOK_INIT(sb_kern_mount, smack_sb_kern_mount),
         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),
         LSM_HOOK_INIT(bprm_committing_creds, smack_bprm_committing_creds),