152 lines
4.7 KiB
Diff
152 lines
4.7 KiB
Diff
From 53469ce0ff5dac0aadfda412c4fa243e341e4b30 Mon Sep 17 00:00:00 2001
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From: =?UTF-8?q?Petr=20P=C3=ADsa=C5=99?= <ppisar@redhat.com>
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Date: Thu, 9 Apr 2015 18:35:04 +0200
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Subject: [PATCH] Fix stack overflow instead of diagnostic for mutual recursion
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inside a lookbehind assertion.
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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Upstream commit porter to 8.36:
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commit 256d94987eecd7eb87b37e1c981a4e753ed8ab7a
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Author: ph10 <ph10@2f5784b3-3f2a-0410-8824-cb99058d5e15>
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Date: Wed Apr 1 15:43:53 2015 +0000
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Fix stack overflow instead of diagnostic for mutual recursion inside a
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lookbehind assertion.
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git-svn-id: svn://vcs.exim.org/pcre/code/trunk@1542 2f5784b3-3f2a-0410-8824-cb99058d5e15
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Signed-off-by: Petr Písař <ppisar@redhat.com>
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---
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pcre_compile.c | 36 +++++++++++++++++++++++++-----------
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testdata/testinput2 | 2 ++
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testdata/testoutput2 | 3 +++
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3 files changed, 30 insertions(+), 11 deletions(-)
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diff --git a/pcre_compile.c b/pcre_compile.c
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index 603e50a..ec7ecf4 100644
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--- a/pcre_compile.c
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+++ b/pcre_compile.c
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@@ -866,6 +866,14 @@ static const pcre_uint8 opcode_possessify[] = {
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};
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+/* Structure for mutual recursion detection. */
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+
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+typedef struct recurse_check {
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+ struct recurse_check *prev;
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+ const pcre_uchar *group;
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+} recurse_check;
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+
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+
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/*************************************************
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* Find an error text *
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@@ -1704,6 +1712,7 @@ Arguments:
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utf TRUE in UTF-8 / UTF-16 / UTF-32 mode
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atend TRUE if called when the pattern is complete
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cd the "compile data" structure
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+ recurses chain of recurse_check to catch mutual recursion
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Returns: the fixed length,
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or -1 if there is no fixed length,
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@@ -1713,10 +1722,11 @@ Returns: the fixed length,
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*/
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static int
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-find_fixedlength(pcre_uchar *code, BOOL utf, BOOL atend, compile_data *cd)
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+find_fixedlength(pcre_uchar *code, BOOL utf, BOOL atend, compile_data *cd,
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+ recurse_check *recurses)
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{
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int length = -1;
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-
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+recurse_check this_recurse;
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register int branchlength = 0;
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register pcre_uchar *cc = code + 1 + LINK_SIZE;
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@@ -1741,7 +1751,8 @@ for (;;)
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case OP_ONCE:
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case OP_ONCE_NC:
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case OP_COND:
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- d = find_fixedlength(cc + ((op == OP_CBRA)? IMM2_SIZE : 0), utf, atend, cd);
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+ d = find_fixedlength(cc + ((op == OP_CBRA)? IMM2_SIZE : 0), utf, atend, cd,
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+ recurses);
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if (d < 0) return d;
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branchlength += d;
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do cc += GET(cc, 1); while (*cc == OP_ALT);
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@@ -1775,7 +1786,15 @@ for (;;)
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cs = ce = (pcre_uchar *)cd->start_code + GET(cc, 1); /* Start subpattern */
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do ce += GET(ce, 1); while (*ce == OP_ALT); /* End subpattern */
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if (cc > cs && cc < ce) return -1; /* Recursion */
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- d = find_fixedlength(cs + IMM2_SIZE, utf, atend, cd);
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+ else /* Check for mutual recursion */
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+ {
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+ recurse_check *r = recurses;
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+ for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break;
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+ if (r != NULL) return -1; /* Mutual recursion */
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+ }
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+ this_recurse.prev = recurses;
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+ this_recurse.group = cs;
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+ d = find_fixedlength(cs + IMM2_SIZE, utf, atend, cd, &this_recurse);
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if (d < 0) return d;
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branchlength += d;
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cc += 1 + LINK_SIZE;
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@@ -2334,11 +2353,6 @@ Arguments:
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Returns: TRUE if what is matched could be empty
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*/
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-typedef struct recurse_check {
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- struct recurse_check *prev;
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- const pcre_uchar *group;
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-} recurse_check;
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-
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static BOOL
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could_be_empty_branch(const pcre_uchar *code, const pcre_uchar *endcode,
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BOOL utf, compile_data *cd, recurse_check *recurses)
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@@ -8225,7 +8239,7 @@ for (;;)
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int fixed_length;
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*code = OP_END;
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fixed_length = find_fixedlength(last_branch, (options & PCRE_UTF8) != 0,
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- FALSE, cd);
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+ FALSE, cd, NULL);
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DPRINTF(("fixed length = %d\n", fixed_length));
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if (fixed_length == -3)
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{
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@@ -9332,7 +9346,7 @@ if (cd->check_lookbehind)
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int end_op = *be;
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*be = OP_END;
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fixed_length = find_fixedlength(cc, (re->options & PCRE_UTF8) != 0, TRUE,
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- cd);
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+ cd, NULL);
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*be = end_op;
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DPRINTF(("fixed length = %d\n", fixed_length));
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if (fixed_length < 0)
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diff --git a/testdata/testinput2 b/testdata/testinput2
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index c01a094..0fc535a 100644
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--- a/testdata/testinput2
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+++ b/testdata/testinput2
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@@ -4086,4 +4086,6 @@ backtracking verbs. --/
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"((?2)+)((?1))"
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+"(?<=((?2))((?1)))"
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+
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/-- End of testinput2 --/
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diff --git a/testdata/testoutput2 b/testdata/testoutput2
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index 0118730..45662a9 100644
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--- a/testdata/testoutput2
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+++ b/testdata/testoutput2
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@@ -14218,4 +14218,7 @@ No match
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"((?2)+)((?1))"
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+"(?<=((?2))((?1)))"
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+Failed: lookbehind assertion is not fixed length at offset 17
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+
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/-- End of testinput2 --/
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--
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2.1.0
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