diff options
Diffstat (limited to 'security/apparmor/match.c')
| -rw-r--r-- | security/apparmor/match.c | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/security/apparmor/match.c b/security/apparmor/match.c index f2d9c57f8794..c5a91600842a 100644 --- a/security/apparmor/match.c +++ b/security/apparmor/match.c @@ -679,34 +679,35 @@ aa_state_t aa_dfa_matchn_until(struct aa_dfa *dfa, aa_state_t start, return state; } -#define inc_wb_pos(wb) \ -do { \ +#define inc_wb_pos(wb) \ +do { \ + BUILD_BUG_ON_NOT_POWER_OF_2(WB_HISTORY_SIZE); \ wb->pos = (wb->pos + 1) & (WB_HISTORY_SIZE - 1); \ - wb->len = (wb->len + 1) & (WB_HISTORY_SIZE - 1); \ + wb->len = (wb->len + 1) > WB_HISTORY_SIZE ? WB_HISTORY_SIZE : \ + wb->len + 1; \ } while (0) /* For DFAs that don't support extended tagging of states */ +/* adjust is only set if is_loop returns true */ static bool is_loop(struct match_workbuf *wb, aa_state_t state, unsigned int *adjust) { - aa_state_t pos = wb->pos; - aa_state_t i; + int pos = wb->pos; + int i; if (wb->history[pos] < state) return false; - for (i = 0; i <= wb->len; i++) { + for (i = 0; i < wb->len; i++) { if (wb->history[pos] == state) { *adjust = i; return true; } - if (pos == 0) - pos = WB_HISTORY_SIZE; - pos--; + /* -1 wraps to WB_HISTORY_SIZE - 1 */ + pos = (pos - 1) & (WB_HISTORY_SIZE - 1); } - *adjust = i; - return true; + return false; } static aa_state_t leftmatch_fb(struct aa_dfa *dfa, aa_state_t start, |