apparmor: add an optional profile attachment string for profiles

Add the ability to take in and report a human readable profile attachment
string for profiles so that attachment specifications can be easily
inspected.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>

4 files changed, 40 insertions, 0 deletions

diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 0fdd08c6ea59..d6329aa7aa98 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -290,6 +290,34 @@ static const struct file_operations aa_fs_profmode_fops = {
         .release        = aa_fs_seq_profile_release,
 };
 
+static int aa_fs_seq_profattach_show(struct seq_file *seq, void *v)
+{
+        struct aa_replacedby *r = seq->private;
+        struct aa_profile *profile = aa_get_profile_rcu(&r->profile);
+        if (profile->attach)
+                seq_printf(seq, "%s\n", profile->attach);
+        else if (profile->xmatch)
+                seq_puts(seq, "<unknown>\n");
+        else
+                seq_printf(seq, "%s\n", profile->base.name);
+        aa_put_profile(profile);
+
+        return 0;
+}
+
+static int aa_fs_seq_profattach_open(struct inode *inode, struct file *file)
+{
+        return aa_fs_seq_profile_open(inode, file, aa_fs_seq_profattach_show);
+}
+
+static const struct file_operations aa_fs_profattach_fops = {
+        .owner          = THIS_MODULE,
+        .open           = aa_fs_seq_profattach_open,
+        .read           = seq_read,
+        .llseek         = seq_lseek,
+        .release        = aa_fs_seq_profile_release,
+};
+
 /** fns to setup dynamic per profile/namespace files **/
 void __aa_fs_profile_rmdir(struct aa_profile *profile)
 {
@@ -385,6 +413,12 @@ int __aa_fs_profile_mkdir(struct aa_profile *profile, struct dentry *parent)
                 goto fail;
         profile->dents[AAFS_PROF_MODE] = dent;
 
+        dent = create_profile_file(dir, "attach", profile,
+                                   &aa_fs_profattach_fops);
+        if (IS_ERR(dent))
+                goto fail;
+        profile->dents[AAFS_PROF_ATTACH] = dent;
+
         list_for_each_entry(child, &profile->base.profiles, base.list) {
                 error = __aa_fs_profile_mkdir(child, prof_child_dir(profile));
                 if (error)
diff --git a/security/apparmor/include/apparmorfs.h b/security/apparmor/include/apparmorfs.h
index 2494e112f2bf..f91712cf1b30 100644
--- a/security/apparmor/include/apparmorfs.h
+++ b/security/apparmor/include/apparmorfs.h
@@ -81,6 +81,7 @@ enum aafs_prof_type {
         AAFS_PROF_PROFS,
         AAFS_PROF_NAME,
         AAFS_PROF_MODE,
+        AAFS_PROF_ATTACH,
         AAFS_PROF_SIZEOF,
 };
 
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h
index 5c72231d1c42..59b36372ae40 100644
--- a/security/apparmor/include/policy.h
+++ b/security/apparmor/include/policy.h
@@ -165,6 +165,7 @@ struct aa_replacedby {
  * @ns: namespace the profile is in
  * @replacedby: is set to the profile that replaced this profile
  * @rename: optional profile name that this profile renamed
+ * @attach: human readable attachment string
  * @xmatch: optional extended matching for unconfined executables names
  * @xmatch_len: xmatch prefix len, used to determine xmatch priority
  * @audit: the auditing mode of the profile
@@ -204,6 +205,7 @@ struct aa_profile {
         struct aa_replacedby *replacedby;
         const char *rename;
 
+        const char *attach;
         struct aa_dfa *xmatch;
         int xmatch_len;
         enum audit_mode audit;
diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
index cac0aa075787..bdaef2e1b2a0 100644
--- a/security/apparmor/policy_unpack.c
+++ b/security/apparmor/policy_unpack.c
@@ -492,6 +492,9 @@ static struct aa_profile *unpack_profile(struct aa_ext *e)
         /* profile renaming is optional */
         (void) unpack_str(e, &profile->rename, "rename");
 
+        /* attachment string is optional */
+        (void) unpack_str(e, &profile->attach, "attach");
+
         /* xmatch is optional and may be NULL */
         profile->xmatch = unpack_dfa(e);
         if (IS_ERR(profile->xmatch)) {