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-rw-r--r--security/apparmor/match.c122
1 files changed, 89 insertions, 33 deletions
diff --git a/security/apparmor/match.c b/security/apparmor/match.c
index 517d77d3c34c..c5a91600842a 100644
--- a/security/apparmor/match.c
+++ b/security/apparmor/match.c
@@ -247,6 +247,42 @@ void aa_dfa_free_kref(struct kref *kref)
dfa_free(dfa);
}
+
+
+/**
+ * remap_data16_to_data32 - remap u16 @old table to a u32 based table
+ * @old: table to remap
+ *
+ * Returns: new table with u32 entries instead of u16.
+ *
+ * Note: will free @old so caller does not have to
+ */
+static struct table_header *remap_data16_to_data32(struct table_header *old)
+{
+ struct table_header *new;
+ size_t tsize;
+ u32 i;
+
+ tsize = table_size(old->td_lolen, YYTD_DATA32);
+ new = kvzalloc(tsize, GFP_KERNEL);
+ if (!new) {
+ kvfree(old);
+ return NULL;
+ }
+ new->td_id = old->td_id;
+ new->td_flags = YYTD_DATA32;
+ new->td_lolen = old->td_lolen;
+
+ for (i = 0; i < old->td_lolen; i++)
+ TABLE_DATAU32(new)[i] = (u32) TABLE_DATAU16(old)[i];
+
+ kvfree(old);
+ if (is_vmalloc_addr(new))
+ vm_unmap_aliases();
+
+ return new;
+}
+
/**
* aa_dfa_unpack - unpack the binary tables of a serialized dfa
* @blob: aligned serialized stream of data to unpack (NOT NULL)
@@ -326,8 +362,10 @@ struct aa_dfa *aa_dfa_unpack(void *blob, size_t size, int flags)
case YYTD_ID_DEF:
case YYTD_ID_NXT:
case YYTD_ID_CHK:
- if (table->td_flags != YYTD_DATA16)
+ if (!(table->td_flags == YYTD_DATA16 ||
+ table->td_flags == YYTD_DATA32)) {
goto fail;
+ }
break;
case YYTD_ID_EC:
if (table->td_flags != YYTD_DATA8)
@@ -342,6 +380,23 @@ struct aa_dfa *aa_dfa_unpack(void *blob, size_t size, int flags)
dfa->tables[table->td_id] = table;
data += table_size(table->td_lolen, table->td_flags);
size -= table_size(table->td_lolen, table->td_flags);
+
+ /*
+ * this remapping has to be done after incrementing data above
+ * for now straight remap, later have dfa support both
+ */
+ switch (table->td_id) {
+ case YYTD_ID_DEF:
+ case YYTD_ID_NXT:
+ case YYTD_ID_CHK:
+ if (table->td_flags == YYTD_DATA16) {
+ table = remap_data16_to_data32(table);
+ if (!table)
+ goto fail;
+ }
+ dfa->tables[table->td_id] = table;
+ break;
+ }
table = NULL;
}
error = verify_table_headers(dfa->tables, flags);
@@ -395,10 +450,10 @@ do { \
aa_state_t aa_dfa_match_len(struct aa_dfa *dfa, aa_state_t start,
const char *str, int len)
{
- u16 *def = DEFAULT_TABLE(dfa);
+ u32 *def = DEFAULT_TABLE(dfa);
u32 *base = BASE_TABLE(dfa);
- u16 *next = NEXT_TABLE(dfa);
- u16 *check = CHECK_TABLE(dfa);
+ u32 *next = NEXT_TABLE(dfa);
+ u32 *check = CHECK_TABLE(dfa);
aa_state_t state = start;
if (state == DFA_NOMATCH)
@@ -434,10 +489,10 @@ aa_state_t aa_dfa_match_len(struct aa_dfa *dfa, aa_state_t start,
*/
aa_state_t aa_dfa_match(struct aa_dfa *dfa, aa_state_t start, const char *str)
{
- u16 *def = DEFAULT_TABLE(dfa);
+ u32 *def = DEFAULT_TABLE(dfa);
u32 *base = BASE_TABLE(dfa);
- u16 *next = NEXT_TABLE(dfa);
- u16 *check = CHECK_TABLE(dfa);
+ u32 *next = NEXT_TABLE(dfa);
+ u32 *check = CHECK_TABLE(dfa);
aa_state_t state = start;
if (state == DFA_NOMATCH)
@@ -472,10 +527,10 @@ aa_state_t aa_dfa_match(struct aa_dfa *dfa, aa_state_t start, const char *str)
*/
aa_state_t aa_dfa_next(struct aa_dfa *dfa, aa_state_t state, const char c)
{
- u16 *def = DEFAULT_TABLE(dfa);
+ u32 *def = DEFAULT_TABLE(dfa);
u32 *base = BASE_TABLE(dfa);
- u16 *next = NEXT_TABLE(dfa);
- u16 *check = CHECK_TABLE(dfa);
+ u32 *next = NEXT_TABLE(dfa);
+ u32 *check = CHECK_TABLE(dfa);
/* current state is <state>, matching character *str */
if (dfa->tables[YYTD_ID_EC]) {
@@ -490,10 +545,10 @@ aa_state_t aa_dfa_next(struct aa_dfa *dfa, aa_state_t state, const char c)
aa_state_t aa_dfa_outofband_transition(struct aa_dfa *dfa, aa_state_t state)
{
- u16 *def = DEFAULT_TABLE(dfa);
+ u32 *def = DEFAULT_TABLE(dfa);
u32 *base = BASE_TABLE(dfa);
- u16 *next = NEXT_TABLE(dfa);
- u16 *check = CHECK_TABLE(dfa);
+ u32 *next = NEXT_TABLE(dfa);
+ u32 *check = CHECK_TABLE(dfa);
u32 b = (base)[(state)];
if (!(b & MATCH_FLAG_OOB_TRANSITION))
@@ -521,10 +576,10 @@ aa_state_t aa_dfa_outofband_transition(struct aa_dfa *dfa, aa_state_t state)
aa_state_t aa_dfa_match_until(struct aa_dfa *dfa, aa_state_t start,
const char *str, const char **retpos)
{
- u16 *def = DEFAULT_TABLE(dfa);
+ u32 *def = DEFAULT_TABLE(dfa);
u32 *base = BASE_TABLE(dfa);
- u16 *next = NEXT_TABLE(dfa);
- u16 *check = CHECK_TABLE(dfa);
+ u32 *next = NEXT_TABLE(dfa);
+ u32 *check = CHECK_TABLE(dfa);
u32 *accept = ACCEPT_TABLE(dfa);
aa_state_t state = start, pos;
@@ -582,10 +637,10 @@ aa_state_t aa_dfa_match_until(struct aa_dfa *dfa, aa_state_t start,
aa_state_t aa_dfa_matchn_until(struct aa_dfa *dfa, aa_state_t start,
const char *str, int n, const char **retpos)
{
- u16 *def = DEFAULT_TABLE(dfa);
+ u32 *def = DEFAULT_TABLE(dfa);
u32 *base = BASE_TABLE(dfa);
- u16 *next = NEXT_TABLE(dfa);
- u16 *check = CHECK_TABLE(dfa);
+ u32 *next = NEXT_TABLE(dfa);
+ u32 *check = CHECK_TABLE(dfa);
u32 *accept = ACCEPT_TABLE(dfa);
aa_state_t state = start, pos;
@@ -624,44 +679,45 @@ 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,
const char *str, struct match_workbuf *wb,
unsigned int *count)
{
- u16 *def = DEFAULT_TABLE(dfa);
+ u32 *def = DEFAULT_TABLE(dfa);
u32 *base = BASE_TABLE(dfa);
- u16 *next = NEXT_TABLE(dfa);
- u16 *check = CHECK_TABLE(dfa);
+ u32 *next = NEXT_TABLE(dfa);
+ u32 *check = CHECK_TABLE(dfa);
aa_state_t state = start, pos;
AA_BUG(!dfa);
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.