From 6bc1968c14e91e03c0851b9c5c5330d91305a853 Mon Sep 17 00:00:00 2001
From: Scott Mayhew <smayhew@redhat.com>
Date: Mon, 31 Jan 2022 13:57:37 -0500
Subject: [PATCH] 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>
---
security/selinux/hooks.c | 88 +++++++++++++++++++++++++++-------------
1 file changed, 59 insertions(+), 29 deletions(-)
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 85282ccc748f3..b60481192b380 100644
--- 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;
}
--
GitLab