From ab3b869791b6122c7be7e68ca4c08e2c2e8815ac Mon Sep 17 00:00:00 2001 From: John Johansen Date: Wed, 16 Aug 2017 05:40:49 -0700 Subject: [PATCH 14/17] apparmor: fix race condition in null profile creation There is a race when null- profile is being created between the initial lookup/creation of the profile and lock/addition of the profile. This could result in multiple version of a profile being added to the list which need to be removed/replaced. Since these are learning profile their is no affect on mediation. Signed-off-by: John Johansen (cherry picked from commit 3aa3de2a4fb8f33ec62b00998bc6b6c6850d41b1) --- security/apparmor/policy.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c index a81a384a63b1..4243b0c3f0e4 100644 --- a/security/apparmor/policy.c +++ b/security/apparmor/policy.c @@ -500,7 +500,8 @@ struct aa_profile *aa_fqlookupn_profile(struct aa_label *base, struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat, const char *base, gfp_t gfp) { - struct aa_profile *profile; + struct aa_profile *p, *profile; + const char *bname; char *name; AA_BUG(!parent); @@ -523,7 +524,8 @@ struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat, name: /* lookup to see if this is a dup creation */ - profile = aa_find_child(parent, basename(name)); + bname = basename(name); + profile = aa_find_child(parent, bname); if (profile) goto out; @@ -544,7 +546,13 @@ struct aa_profile *aa_new_null_profile(struct aa_profile *parent, bool hat, profile->policy.dfa = aa_get_dfa(nulldfa); mutex_lock(&profile->ns->lock); - __add_profile(&parent->base.profiles, profile); + p = __find_child(&parent->base.profiles, bname); + if (p) { + aa_free_profile(profile); + profile = aa_get_profile(p); + } else { + __add_profile(&parent->base.profiles, profile); + } mutex_unlock(&profile->ns->lock); /* refcount released by caller */ -- 2.11.0