From dae6029325a4744e639eb048c13f53c24320aeda Mon Sep 17 00:00:00 2001 From: John Johansen Date: Sat, 31 Aug 2019 15:55:45 -0700 Subject: [PATCH] apparmor: add consistency check between state and dfa diff encode flags Check that a states diff encode flag is only set if diff encode is enabled in the dfa header. Signed-off-by: John Johansen --- security/apparmor/match.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/security/apparmor/match.c b/security/apparmor/match.c index b477352..651dbb6 100644 --- a/security/apparmor/match.c +++ b/security/apparmor/match.c @@ -206,6 +206,12 @@ static int verify_dfa(struct aa_dfa *dfa) pr_err("AppArmor DFA state with invalid match flags"); goto out; } + if ((BASE_TABLE(dfa)[i] & MATCH_FLAG_DIFF_ENCODE)) { + if (!(dfa->flags & YYTH_FLAG_DIFF_ENCODE)) { + pr_err("AppArmor DFA diff encoded transition state without header flag"); + goto out; + } + } if (base_idx(BASE_TABLE(dfa)[i]) + 255 >= trans_count) { pr_err("AppArmor DFA next/check upper bounds error\n"); goto out; -- 2.7.4