diff options
Diffstat (limited to 'security/apparmor/match.c')
| -rw-r--r-- | security/apparmor/match.c | 58 |
1 files changed, 42 insertions, 16 deletions
diff --git a/security/apparmor/match.c b/security/apparmor/match.c index 8fa0a1494acd..e9fac67e5178 100644 --- a/security/apparmor/match.c +++ b/security/apparmor/match.c @@ -160,9 +160,10 @@ static int verify_dfa(struct aa_dfa *dfa) if (state_count == 0) goto out; for (i = 0; i < state_count; i++) { - if (!(BASE_TABLE(dfa)[i] & MATCH_FLAG_DIFF_ENCODE) && - (DEFAULT_TABLE(dfa)[i] >= state_count)) + if (DEFAULT_TABLE(dfa)[i] >= state_count) { + pr_err("AppArmor DFA default state out of bounds"); goto out; + } if (BASE_TABLE(dfa)[i] & MATCH_FLAGS_INVALID) { pr_err("AppArmor DFA state with invalid match flags"); goto out; @@ -201,16 +202,31 @@ static int verify_dfa(struct aa_dfa *dfa) size_t j, k; for (j = i; - (BASE_TABLE(dfa)[j] & MATCH_FLAG_DIFF_ENCODE) && - !(BASE_TABLE(dfa)[j] & MARK_DIFF_ENCODE); + ((BASE_TABLE(dfa)[j] & MATCH_FLAG_DIFF_ENCODE) && + !(BASE_TABLE(dfa)[j] & MARK_DIFF_ENCODE_VERIFIED)); j = k) { + if (BASE_TABLE(dfa)[j] & MARK_DIFF_ENCODE) + /* loop in current chain */ + goto out; k = DEFAULT_TABLE(dfa)[j]; if (j == k) + /* self loop */ goto out; - if (k < j) - break; /* already verified */ BASE_TABLE(dfa)[j] |= MARK_DIFF_ENCODE; } + /* move mark to verified */ + for (j = i; + (BASE_TABLE(dfa)[j] & MATCH_FLAG_DIFF_ENCODE); + j = k) { + k = DEFAULT_TABLE(dfa)[j]; + if (j < i) + /* jumps to state/chain that has been + * verified + */ + break; + BASE_TABLE(dfa)[j] &= ~MARK_DIFF_ENCODE; + BASE_TABLE(dfa)[j] |= MARK_DIFF_ENCODE_VERIFIED; + } } error = 0; @@ -463,13 +479,18 @@ aa_state_t aa_dfa_match_len(struct aa_dfa *dfa, aa_state_t start, if (dfa->tables[YYTD_ID_EC]) { /* Equivalence class table defined */ u8 *equiv = EQUIV_TABLE(dfa); - for (; len; len--) - match_char(state, def, base, next, check, - equiv[(u8) *str++]); + for (; len; len--) { + u8 c = equiv[(u8) *str]; + + match_char(state, def, base, next, check, c); + str++; + } } else { /* default is direct to next state */ - for (; len; len--) - match_char(state, def, base, next, check, (u8) *str++); + for (; len; len--) { + match_char(state, def, base, next, check, (u8) *str); + str++; + } } return state; @@ -503,13 +524,18 @@ aa_state_t aa_dfa_match(struct aa_dfa *dfa, aa_state_t start, const char *str) /* Equivalence class table defined */ u8 *equiv = EQUIV_TABLE(dfa); /* default is direct to next state */ - while (*str) - match_char(state, def, base, next, check, - equiv[(u8) *str++]); + while (*str) { + u8 c = equiv[(u8) *str]; + + match_char(state, def, base, next, check, c); + str++; + } } else { /* default is direct to next state */ - while (*str) - match_char(state, def, base, next, check, (u8) *str++); + while (*str) { + match_char(state, def, base, next, check, (u8) *str); + str++; + } } return state; |