selinux: try to use preparsed sid before calling parse_sid()

Avoid unnecessary parsing of sids that have already been parsed via
selinux_sb_eat_lsm_opts().

Signed-off-by: Scott Mayhew <smayhew@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 85282ccc748f398a126ab53b33bceddcd6fd3c9c..b60481192b3807265b52c79f362274761b58565b 100644 (file)
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -675,36 +675,48 @@ static int selinux_set_mnt_opts(struct super_block *sb,
         */
        if (opts) {
                if (opts->fscontext) {
-                       rc = parse_sid(sb, opts->fscontext, &fscontext_sid);
-                       if (rc)
-                               goto out;
+                       if (opts->fscontext_sid == SECSID_NULL) {
+                               rc = parse_sid(sb, opts->fscontext, &fscontext_sid);
+                               if (rc)
+                                       goto out;
+                       } else
+                               fscontext_sid = opts->fscontext_sid;
                        if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
                                        fscontext_sid))
                                goto out_double_mount;
                        sbsec->flags |= FSCONTEXT_MNT;
                }
                if (opts->context) {
-                       rc = parse_sid(sb, opts->context, &context_sid);
-                       if (rc)
-                               goto out;
+                       if (opts->context_sid == SECSID_NULL) {
+                               rc = parse_sid(sb, opts->context, &context_sid);
+                               if (rc)
+                                       goto out;
+                       } else
+                               context_sid = opts->context_sid;
                        if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
                                        context_sid))
                                goto out_double_mount;
                        sbsec->flags |= CONTEXT_MNT;
                }
                if (opts->rootcontext) {
-                       rc = parse_sid(sb, opts->rootcontext, &rootcontext_sid);
-                       if (rc)
-                               goto out;
+                       if (opts->rootcontext_sid == SECSID_NULL) {
+                               rc = parse_sid(sb, opts->rootcontext, &rootcontext_sid);
+                               if (rc)
+                                       goto out;
+                       } else
+                               rootcontext_sid = opts->rootcontext_sid;
                        if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
                                        rootcontext_sid))
                                goto out_double_mount;
                        sbsec->flags |= ROOTCONTEXT_MNT;
                }
                if (opts->defcontext) {
-                       rc = parse_sid(sb, opts->defcontext, &defcontext_sid);
-                       if (rc)
-                               goto out;
+                       if (opts->defcontext_sid == SECSID_NULL) {
+                               rc = parse_sid(sb, opts->defcontext, &defcontext_sid);
+                               if (rc)
+                                       goto out;
+                       } else
+                               defcontext_sid = opts->defcontext_sid;
                        if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
                                        defcontext_sid))
                                goto out_double_mount;
@@ -2709,7 +2721,6 @@ static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
 {
        struct selinux_mnt_opts *opts = mnt_opts;
        struct superblock_security_struct *sbsec = selinux_superblock(sb);
-       u32 sid;
        int rc;
 
        if (!(sbsec->flags & SE_SBINITIALIZED))
@@ -2719,33 +2730,48 @@ static int selinux_sb_remount(struct super_block *sb, void *mnt_opts)
                return 0;
 
        if (opts->fscontext) {
-               rc = parse_sid(sb, opts->fscontext, &sid);
-               if (rc)
-                       return rc;
-               if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
+               if (opts->fscontext_sid == SECSID_NULL) {
+                       rc = parse_sid(sb, opts->fscontext,
+                                      &opts->fscontext_sid);
+                       if (rc)
+                               return rc;
+               }
+               if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
+                              opts->fscontext_sid))
                        goto out_bad_option;
        }
        if (opts->context) {
-               rc = parse_sid(sb, opts->context, &sid);
-               if (rc)
-                       return rc;
-               if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
+               if (opts->context_sid == SECSID_NULL) {
+                       rc = parse_sid(sb, opts->context, &opts->context_sid);
+                       if (rc)
+                               return rc;
+               }
+               if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
+                              opts->context_sid))
                        goto out_bad_option;
        }
        if (opts->rootcontext) {
                struct inode_security_struct *root_isec;
                root_isec = backing_inode_security(sb->s_root);
-               rc = parse_sid(sb, opts->rootcontext, &sid);
-               if (rc)
-                       return rc;
-               if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
+               if (opts->rootcontext_sid == SECSID_NULL) {
+                       rc = parse_sid(sb, opts->rootcontext,
+                                      &opts->rootcontext_sid);
+                       if (rc)
+                               return rc;
+               }
+               if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
+                              opts->rootcontext_sid))
                        goto out_bad_option;
        }
        if (opts->defcontext) {
-               rc = parse_sid(sb, opts->defcontext, &sid);
-               if (rc)
-                       return rc;
-               if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
+               if (opts->defcontext_sid == SECSID_NULL) {
+                       rc = parse_sid(sb, opts->defcontext,
+                                      &opts->defcontext_sid);
+                       if (rc)
+                               return rc;
+               }
+               if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
+                              opts->defcontext_sid))
                        goto out_bad_option;
        }
        return 0;
@@ -2843,6 +2869,10 @@ static int selinux_fs_context_dup(struct fs_context *fc,
                if (!opts->defcontext)
                        return -ENOMEM;
        }
+       opts->fscontext_sid = src->fscontext_sid;
+       opts->context_sid = src->context_sid;
+       opts->rootcontext_sid = src->rootcontext_sid;
+       opts->defcontext_sid = src->defcontext_sid;
        return 0;
 }