apparmor: Fully initialize aa_perms struct when answering userspace query

Fully initialize the aa_perms struct in profile_query_cb() to avoid the
potential of using an uninitialized struct member's value in a response
to a query from userspace.

Detected by CoverityScan CID#1415126 ("Uninitialized scalar variable")

Fixes: 4f3b3f2d79a4 ("apparmor: add profile permission query ability")
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>

diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 949dd8a..e09fe4d 100644 (file)
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -603,7 +603,7 @@ static const struct file_operations aa_fs_ns_revision_fops = {
 static void profile_query_cb(struct aa_profile *profile, struct aa_perms *perms,
                             const char *match_str, size_t match_len)
 {
-       struct aa_perms tmp;
+       struct aa_perms tmp = { };
        struct aa_dfa *dfa;
        unsigned int state = 0;
 
@@ -613,7 +613,6 @@ static void profile_query_cb(struct aa_profile *profile, struct aa_perms *perms,
                dfa = profile->file.dfa;
                state = aa_dfa_match_len(dfa, profile->file.start,
                                         match_str + 1, match_len - 1);
-               tmp = nullperms;
                if (state) {
                        struct path_cond cond = { };
 
@@ -627,8 +626,6 @@ static void profile_query_cb(struct aa_profile *profile, struct aa_perms *perms,
                                         match_str, match_len);
                if (state)
                        aa_compute_perms(dfa, state, &tmp);
-               else
-                       tmp = nullperms;
        }
        aa_apply_modes_to_perms(profile, &tmp);
        aa_perms_accum_raw(perms, &tmp);