changeset 17304:d08258969ee9

regex: fix buffer overrun in regexp matcher * lib/regexec.c (extend_buffers): Add parameter min_len. (check_matching): Pass minimum needed length. (clean_state_log_if_needed): Likewise. (get_subexp): Likewise.
author Andreas Schwab <schwab@suse.de>
date Tue, 29 Jan 2013 22:33:51 -0800
parents eb68457f3843
children 0e5a583a2a8d
files ChangeLog lib/regexec.c
diffstat 2 files changed, 17 insertions(+), 7 deletions(-) [+]
line wrap: on
line diff
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2013-01-29  Andreas Schwab  <schwab@suse.de>
+
+	regex: fix buffer overrun in regexp matcher
+	* lib/regexec.c (extend_buffers): Add parameter min_len.
+	(check_matching): Pass minimum needed length.
+	(clean_state_log_if_needed): Likewise.
+	(get_subexp): Likewise.
+
 2013-01-28  Pádraig Brady  <P@draigBrady.com>
 
 	mountlist: don't consider "devtmpfs" as dummy
--- a/lib/regexec.c
+++ b/lib/regexec.c
@@ -199,7 +199,7 @@
 static bool check_node_accept (const re_match_context_t *mctx,
 			       const re_token_t *node, Idx idx)
      internal_function;
-static reg_errcode_t extend_buffers (re_match_context_t *mctx)
+static reg_errcode_t extend_buffers (re_match_context_t *mctx, int min_len)
      internal_function;
 
 /* Entry point for POSIX code.  */
@@ -1176,7 +1176,7 @@
 	  || (BE (next_char_idx >= mctx->input.valid_len, 0)
 	      && mctx->input.valid_len < mctx->input.len))
 	{
-	  err = extend_buffers (mctx);
+	  err = extend_buffers (mctx, next_char_idx + 1);
 	  if (BE (err != REG_NOERROR, 0))
 	    {
 	      assert (err == REG_ESPACE);
@@ -1756,7 +1756,7 @@
 	  && mctx->input.valid_len < mctx->input.len))
     {
       reg_errcode_t err;
-      err = extend_buffers (mctx);
+      err = extend_buffers (mctx, next_state_log_idx + 1);
       if (BE (err != REG_NOERROR, 0))
 	return err;
     }
@@ -2813,7 +2813,7 @@
 		  if (bkref_str_off >= mctx->input.len)
 		    break;
 
-		  err = extend_buffers (mctx);
+		  err = extend_buffers (mctx, bkref_str_off + 1);
 		  if (BE (err != REG_NOERROR, 0))
 		    return err;
 
@@ -4128,7 +4128,7 @@
 
 static reg_errcode_t
 internal_function __attribute_warn_unused_result__
-extend_buffers (re_match_context_t *mctx)
+extend_buffers (re_match_context_t *mctx, int min_len)
 {
   reg_errcode_t ret;
   re_string_t *pstr = &mctx->input;
@@ -4138,8 +4138,10 @@
           <= pstr->bufs_len, 0))
     return REG_ESPACE;
 
-  /* Double the lengths of the buffers.  */
-  ret = re_string_realloc_buffers (pstr, MIN (pstr->len, pstr->bufs_len * 2));
+  /* Double the lengths of the buffers, but allocate at least MIN_LEN.  */
+  ret = re_string_realloc_buffers (pstr,
+				   MAX (min_len,
+					MIN (pstr->len, pstr->bufs_len * 2)));
   if (BE (ret != REG_NOERROR, 0))
     return ret;