File 0002-fix-find_fixedlen-stk-overflow-w-mutual-recursion.patch of Package erlang
From f74cdcfa2967a946f5e9e4de4c5c2fb9def31f84 Mon Sep 17 00:00:00 2001
From: Zephyr Pellerin <zv@nxvr.org>
Date: Sat, 18 Jun 2016 15:42:42 -0700
Subject: [PATCH 2/3] fix find_fixedlen stk overflow w/ mutual recursion
---
erts/emulator/pcre/pcre_compile.c | 33 ++++++++++++++++++++++-----------
1 file changed, 22 insertions(+), 11 deletions(-)
diff --git a/erts/emulator/pcre/pcre_compile.c b/erts/emulator/pcre/pcre_compile.c
index d48126a55d..e422e54f73 100644
--- a/erts/emulator/pcre/pcre_compile.c
+++ b/erts/emulator/pcre/pcre_compile.c
@@ -1734,6 +1734,7 @@ Arguments:
utf TRUE in UTF-8 / UTF-16 / UTF-32 mode
atend TRUE if called when the pattern is complete
cd the "compile data" structure
+ recurses chain of recurse_check to catch mutual recursion
Returns: the fixed length,
or -1 if there is no fixed length,
@@ -1743,10 +1744,11 @@ Returns: the fixed length,
*/
static int
-find_fixedlength(pcre_uchar *code, BOOL utf, BOOL atend, compile_data *cd)
+find_fixedlength(pcre_uchar *code, BOOL utf, BOOL atend, compile_data *cd,
+ recurse_check *recurses)
{
int length = -1;
-
+recurse_check this_recurse;
register int branchlength = 0;
register pcre_uchar *cc = code + 1 + LINK_SIZE;
@@ -1771,7 +1773,8 @@ for (;;)
case OP_ONCE:
case OP_ONCE_NC:
case OP_COND:
- d = find_fixedlength(cc + ((op == OP_CBRA)? IMM2_SIZE : 0), utf, atend, cd);
+ d = find_fixedlength(cc + ((op == OP_CBRA)? IMM2_SIZE : 0), utf, atend, cd,
+ recurses);
if (d < 0) return d;
branchlength += d;
do cc += GET(cc, 1); while (*cc == OP_ALT);
@@ -1805,7 +1808,15 @@ for (;;)
cs = ce = (pcre_uchar *)cd->start_code + GET(cc, 1); /* Start subpattern */
do ce += GET(ce, 1); while (*ce == OP_ALT); /* End subpattern */
if (cc > cs && cc < ce) return -1; /* Recursion */
- d = find_fixedlength(cs + IMM2_SIZE, utf, atend, cd);
+ else /* Check for mutual recursion */
+ {
+ recurse_check *r = recurses;
+ for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break;
+ if (r != NULL) return -1; /* Mutual recursion */
+ }
+ this_recurse.prev = recurses;
+ this_recurse.group = cs;
+ d = find_fixedlength(cs + IMM2_SIZE, utf, atend, cd, &this_recurse);
if (d < 0) return d;
branchlength += d;
cc += 1 + LINK_SIZE;
@@ -1818,7 +1829,7 @@ for (;;)
case OP_ASSERTBACK:
case OP_ASSERTBACK_NOT:
do cc += GET(cc, 1); while (*cc == OP_ALT);
- cc += PRIV(OP_lengths)[*cc];
+ cc += 1 + LINK_SIZE;
break;
/* Skip over things that don't match chars */
@@ -1837,13 +1848,13 @@ for (;;)
case OP_COMMIT:
case OP_CREF:
case OP_DEF:
+ case OP_NCREF:
+ case OP_NRREF:
case OP_DOLL:
case OP_DOLLM:
case OP_EOD:
case OP_EODN:
case OP_FAIL:
- case OP_NCREF:
- case OP_NRREF:
case OP_NOT_WORD_BOUNDARY:
case OP_PRUNE:
case OP_REVERSE:
@@ -1938,10 +1949,10 @@ for (;;)
switch (*cc)
{
- case OP_CRPLUS:
- case OP_CRMINPLUS:
case OP_CRSTAR:
case OP_CRMINSTAR:
+ case OP_CRPLUS:
+ case OP_CRMINPLUS:
case OP_CRQUERY:
case OP_CRMINQUERY:
return -1;
@@ -7255,7 +7266,7 @@ for (;;)
int fixed_length;
*code = OP_END;
fixed_length = find_fixedlength(last_branch, (options & PCRE_UTF8) != 0,
- FALSE, cd);
+ FALSE, cd, NULL);
DPRINTF(("fixed length = %d\n", fixed_length));
if (fixed_length == -3)
{
@@ -8269,7 +8280,7 @@ if (cd->check_lookbehind)
int end_op = *be;
*be = OP_END;
fixed_length = find_fixedlength(cc, (re->options & PCRE_UTF8) != 0, TRUE,
- cd);
+ cd, NULL);
*be = end_op;
DPRINTF(("fixed length = %d\n", fixed_length));
if (fixed_length < 0)
--
2.13.6