diff options
| -rw-r--r-- | security/apparmor/policy.c | 24 |
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); } |