1 files changed, 23 insertions, 1 deletions

diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c
index cf5fd220309b..813200384d97 100644
--- a/security/apparmor/policy.c
+++ b/security/apparmor/policy.c
@@ -724,6 +724,8 @@ fail:
  */
 static void free_profile(struct aa_profile *profile)
 {
+        struct aa_profile *p;
+
         AA_DEBUG("%s(%p)\n", __func__, profile);
 
         if (!profile)
@@ -751,7 +753,27 @@ static void free_profile(struct aa_profile *profile)
         aa_put_dfa(profile->xmatch);
         aa_put_dfa(profile->policy.dfa);
 
-        aa_put_profile(profile->replacedby);
+        /* put the profile reference for replacedby, but not via
+         * put_profile(kref_put).
+         * replacedby can form a long chain that can result in cascading
+         * frees that blows the stack because kref_put makes a nested fn
+         * call (it looks like recursion, with free_profile calling
+         * free_profile) for each profile in the chain lp#1056078.
+         */
+        for (p = profile->replacedby; p; ) {
+                if (atomic_dec_and_test(&p->base.count.refcount)) {
+                        /* no more refs on p, grab its replacedby */
+                        struct aa_profile *next = p->replacedby;
+                        /* break the chain */
+                        p->replacedby = NULL;
+                        /* now free p, chain is broken */
+                        free_profile(p);
+
+                        /* follow up with next profile in the chain */
+                        p = next;
+                } else
+                        break;
+        }
 
         kzfree(profile);
 }