[libsepol] Fix libsepol.stack messages in audit2allow/audit2why

[Daniel J Walsh]

commit 5a38f90989b286a84b66dc03512c9139544fa61f
Author: Dan Walsh <dwalsh at redhat.com>
Date:   Tue Jan 8 13:35:56 2013 -0500

    Fix libsepol.stack messages in audit2allow/audit2why

 tmp.patch |   98 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 98 insertions(+), 0 deletions(-)
---
diff --git a/tmp.patch b/tmp.patch
new file mode 100644
index 0000000..41ebb90
--- /dev/null
+++ b/tmp.patch
@@ -0,0 +1,98 @@
+commit 541cb790e1e6ce666c4deb6ebac3212f1bc8f289
+Author: Eric Paris <eparis at redhat.com>
+Date:   Tue Jan 8 11:42:21 2013 -0500
+
+    start fixing stuff
+
+diff --git a/libsepol/src/services.c b/libsepol/src/services.c
+index 9b42d8d..23cef4c 100644
+--- a/libsepol/src/services.c
++++ b/libsepol/src/services.c
+@@ -47,7 +47,6 @@
+ #define REASON_BUF_SIZE 30000
+ /* The maximum size of each malloc'd expression buffer */
+ #define EXPR_BUF_SIZE 1000
+-/* Number expressions in a constraint - max seen in MLS policy is 21 */
+ #define EXPR_BUFFERS 30
+ 
+ #include <stdlib.h>
+@@ -79,27 +78,42 @@ static sidtab_t mysidtab, *sidtab = &mysidtab;
+ static policydb_t mypolicydb, *policydb = &mypolicydb;
+ 
+ /* Stack services for RPN to infix conversion. Size is num of expr bufs */
+-char *stack[EXPR_BUFFERS];
+-int tos = 0;
+- 
+-void push(char * expr_ptr)
++static char **stack;
++static int stack_len;
++static int next_stack_entry;
++
++static void push(char * expr_ptr)
+ {
+-	if (tos >= EXPR_BUFFERS) {
+-		ERR(NULL, "Stack is full");
+-		return;
++	if (next_stack_entry >= stack_len) {
++		char **new_stack = stack;
++		int new_stack_len;
++
++		if (stack_len == 0)
++			new_stack_len = 32;
++		else
++			new_stack_len = stack_len * 2;
++
++		new_stack = realloc(stack, new_stack_len * sizeof(*stack));
++		if (!new_stack) {
++			ERR(NULL, "unable to allocate space");
++			return;
++		}
++		stack_len = new_stack_len;
++		stack = new_stack;
+ 	}
+-	stack[tos] = expr_ptr;
+-	tos++;
++	stack[next_stack_entry] = expr_ptr;
++	next_stack_entry++;
+ }
+- 
+-char *pop()
++
++static char *pop(void)
+ {
+-	tos--;
+-	if (tos < 0) {
+-		ERR(NULL, "Stack is Empty");
++	next_stack_entry--;
++	if (next_stack_entry < 0) {
++		next_stack_entry = 0;
++		ERR(NULL, "pop called with no stack entries");
+ 		return NULL;
+ 	}
+-	return (char *)stack[tos];
++	return stack[next_stack_entry];
+ }
+ /* End Stack services */
+ 
+@@ -322,6 +336,10 @@ static int constraint_expr_eval_reason(context_struct_t * scontext,
+ 
+ 	/* Original function but with buffer support */
+ 	for (e = constraint->expr; e; e = e->next) {
++		if (expr_counter >= EXPR_BUFFERS) {
++			ERR(NULL, "%s: expr_buf overflow", __func__);
++			return -ENOMEM;
++		}
+ 		/* malloc a buffer to store each expression text component */
+ 		expr_buf[expr_counter] = malloc(EXPR_BUF_SIZE);
+ 		if (!expr_buf[expr_counter]) {
+@@ -622,6 +640,10 @@ static int constraint_expr_eval_reason(context_struct_t * scontext,
+ 	for (x = 0; expr_buf[x] != NULL; x++) {
+ 		if (strncmp(expr_buf[x], "and", 3) == 0 || strncmp(expr_buf[x],
+ 					"or", 2) == 0) {
++			if (answer_counter >= EXPR_BUFFERS) {
++				ERR(NULL, "%s: answer_buf overflow", __func__);
++				return -ENOMEM;
++			}
+ 			b = pop();
+ 			b_len = strlen(b);
+ 			a = pop();