LSM: lift extracting and parsing LSM options into the caller of ->sb_remount()

This paves the way for retaining the LSM options from a common filesystem
mount context during a mount parameter parsing phase to be instituted prior
to actual mount/reconfiguration actions.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 12 insertions, 35 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index ba229d4a64d3..ba3e2917bd24 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -2812,39 +2812,22 @@ out:
         return rc;
 }
 
-static int selinux_sb_remount(struct super_block *sb, void *data)
+static int selinux_sb_remount(struct super_block *sb,
+                              struct security_mnt_opts *opts)
 {
-        int rc, i, *flags;
-        struct security_mnt_opts opts;
-        char *secdata, **mount_options;
+        int i, *flags;
+        char **mount_options;
         struct superblock_security_struct *sbsec = sb->s_security;
 
         if (!(sbsec->flags & SE_SBINITIALIZED))
                 return 0;
 
-        if (!data)
-                return 0;
-
-        if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
-                return 0;
-
-        security_init_mnt_opts(&opts);
-        secdata = alloc_secdata();
-        if (!secdata)
-                return -ENOMEM;
-        rc = selinux_sb_copy_data(data, secdata);
-        if (rc)
-                goto out_free_secdata;
-
-        rc = selinux_parse_opts_str(secdata, &opts);
-        if (rc)
-                goto out_free_secdata;
+        mount_options = opts->mnt_opts;
+        flags = opts->mnt_opts_flags;
 
-        mount_options = opts.mnt_opts;
-        flags = opts.mnt_opts_flags;
-
-        for (i = 0; i < opts.num_mnt_opts; i++) {
+        for (i = 0; i < opts->num_mnt_opts; i++) {
                 u32 sid;
+                int rc;
 
                 if (flags[i] == SBLABEL_MNT)
                         continue;
@@ -2855,9 +2838,8 @@ static int selinux_sb_remount(struct super_block *sb, void *data)
                         pr_warn("SELinux: security_context_str_to_sid"
                                "(%s) failed for (dev %s, type %s) errno=%d\n",
                                mount_options[i], sb->s_id, sb->s_type->name, rc);
-                        goto out_free_opts;
+                        return rc;
                 }
-                rc = -EINVAL;
                 switch (flags[i]) {
                 case FSCONTEXT_MNT:
                         if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
@@ -2880,21 +2862,16 @@ static int selinux_sb_remount(struct super_block *sb, void *data)
                                 goto out_bad_option;
                         break;
                 default:
-                        goto out_free_opts;
+                        return -EINVAL;
                 }
         }
+        return 0;
 
-        rc = 0;
-out_free_opts:
-        security_free_mnt_opts(&opts);
-out_free_secdata:
-        free_secdata(secdata);
-        return rc;
 out_bad_option:
         pr_warn("SELinux: unable to change security options "
                "during remount (dev %s, type=%s)\n", sb->s_id,
                sb->s_type->name);
-        goto out_free_opts;
+        return -EINVAL;
 }
 
 static int selinux_sb_kern_mount(struct super_block *sb, int flags,