[PATCH] Fix regex crash

[PATCH] Fix regex crash

[Jakub Jelinek]

Hi!

The following testcase (invalid UTF-8) causes regex segfault.
I'm not sure if it is a good idea to rely on _NL_COLLATE_SYMB_EXTRAMB+1
follow _NL_COLLATE_SYMB_EXTRAMB in LC_COLLATE data, but I don't see how
else easily find out where it ends.
Without that find_collation_sequence_value loops until it falls off the
cliff (likely at the end of locale-archive mapping).

2004-01-11  Jakub Jelinek  <jakub@redhat.com>

	* posix/regexec.c (check_node_accept_bytes): Return 0 if char_len
	is 0.
	(find_collation_sequence_value): Don't look beyond end of
	SYMB_EXTRAMB table.
	* posix/Makefile (tests): Add bug-regex23.
	(bug-regex23-ENV): New.

--- libc/posix/regexec.c.jj	2004-02-09 14:52:33.000000000 +0100
+++ libc/posix/regexec.c	2004-02-11 16:14:13.000000000 +0100
@@ -3666,7 +3666,7 @@ check_node_accept_bytes (dfa, node_idx, 
     }
 
   elem_len = re_string_elem_size_at (input, str_idx);
-  if (elem_len <= 1 && char_len <= 1)
+  if ((elem_len <= 1 && char_len <= 1) || char_len == 0)
     return 0;
 
   if (node->type == COMPLEX_BRACKET)
@@ -3847,8 +3847,10 @@ find_collation_sequence_value (mbs, mbs_
       int32_t idx;
       const unsigned char *extra = (const unsigned char *)
 	_NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB);
+      int32_t extrasize = (const unsigned char *)
+	_NL_CURRENT (LC_COLLATE, _NL_COLLATE_SYMB_EXTRAMB + 1) - extra;
 
-      for (idx = 0; ;)
+      for (idx = 0; idx < extrasize;)
 	{
 	  int mbs_cnt, found = 0;
 	  int32_t elem_mbs_len;
@@ -3878,6 +3880,7 @@ find_collation_sequence_value (mbs, mbs_
 	  /* Skip the collation sequence value.  */
 	  idx += sizeof (uint32_t);
 	}
+      return UINT_MAX;
     }
 }
 # endif /* _LIBC */
--- libc/posix/Makefile.jj	2004-01-12 10:52:37.000000000 +0100
+++ libc/posix/Makefile	2004-02-11 15:44:45.000000000 +0100
@@ -79,7 +79,7 @@ tests		:= tstgetopt testfnm runtests run
 		   bug-regex8 bug-regex9 bug-regex10 bug-regex11 bug-regex12 \
 		   bug-regex13 bug-regex14 bug-regex15 bug-regex16 \
 		   bug-regex17 bug-regex18 bug-regex19 bug-regex20 \
-		   bug-regex21 bug-regex22 tst-nice tst-nanosleep \
+		   bug-regex21 bug-regex22 bug-regex23 tst-nice tst-nanosleep \
 		   transbug tst-rxspencer tst-pcre tst-boost
 ifeq (yes,$(build-shared))
 test-srcs	:= globtest
@@ -163,6 +163,7 @@ bug-regex18-ENV = LOCPATH=$(common-objpf
 bug-regex19-ENV = LOCPATH=$(common-objpfx)localedata
 bug-regex20-ENV = LOCPATH=$(common-objpfx)localedata
 bug-regex22-ENV = LOCPATH=$(common-objpfx)localedata
+bug-regex23-ENV = LOCPATH=$(common-objpfx)localedata
 tst-rxspencer-ARGS = --utf8 rxspencer/tests
 tst-rxspencer-ENV = LOCPATH=$(common-objpfx)localedata
 tst-pcre-ARGS = PCRE.tests
--- libc/posix/bug-regex23.c.jj	2004-02-11 15:39:24.000000000 +0100
+++ libc/posix/bug-regex23.c	2004-02-11 15:40:17.000000000 +0100
@@ -0,0 +1,35 @@
+/* Test we don't segfault on invalid UTF-8 sequence.
+   Copyright (C) 2004 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Jakub Jelinek <jakub@redhat.com>, 2004.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#include <locale.h>
+#include <regex.h>
+#include <string.h>
+
+int
+main (void)
+{
+  regex_t r;
+
+  memset (&r, 0, sizeof (r));
+  setlocale (LC_ALL, "de_DE.UTF-8");
+  regcomp (&r, "[-a-z_0-9.]+@[-a-z_0-9.]+", REG_EXTENDED | REG_ICASE);
+  regexec (&r, "\xe7\xb7\x95\xe7\x97", 0, NULL, 0);
+  return 0;
+}

	Jakub

Re: [PATCH] Fix regex crash

[Ulrich Drepper]

I've applied the patch.

-- 
➧ Ulrich Drepper ➧ Red Hat, Inc. ➧ 444 Castro St ➧ Mountain View, CA ❖