PR/474: Add a limit to the size of regex searches to prevent performance

issues.

diff --git a/ChangeLog b/ChangeLog
index 2a83abc3a50c33a2514215345971240c6686c533..8b980bada39db610c72bc839d07fdeeea8c310a6 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2015-09-11  13:25  Christos Zoulas <christos@zoulas.com>
+
+       * add a limit to the length of regex searches
+
 2015-09-08   9:50  Christos Zoulas <christos@zoulas.com>
 
        * fix problems with --parameter (Christoph Biedl)

diff --git a/doc/file.man b/doc/file.man
index 6f782215d57c2f9e288d3a6e1d7bbc92997d573a..3e10658d207980ea63d3b8ff77f6a4e6a91aebad 100644 (file)
--- a/doc/file.man
+++ b/doc/file.man
@@ -1,5 +1,5 @@
-.\" $File: file.man,v 1.117 2015/06/03 19:51:27 christos Exp $
-.Dd June 3, 2015
+.\" $File: file.man,v 1.118 2015/09/11 17:24:09 christos Exp $
+.Dd September 11, 2015
 .Dt FILE __CSECTION__
 .Os
 .Sh NAME
@@ -316,6 +316,7 @@ Set various parameter limits.
 .It Li elf_notes Ta 256 Ta max ELF notes processed
 .It Li elf_phnum Ta 128 Ta max ELF program sections processed
 .It Li elf_shnum Ta 32768 Ta max ELF sections processed
+.It Li regex Ta 8192 Ta length limit for regex searches
 .El
 .It Fl r , Fl Fl raw
 Don't translate unprintable characters to \eooo.

diff --git a/doc/libmagic.man b/doc/libmagic.man
index 64170a31b2ed959d688426a2538a54a5b0905910..8f5c0327fa20e20995f12f3e7a2f735c2d3087e0 100644 (file)
--- a/doc/libmagic.man
+++ b/doc/libmagic.man
@@ -1,4 +1,4 @@
-.\" $File: libmagic.man,v 1.37 2015/06/03 18:21:24 christos Exp $
+.\" $File: libmagic.man,v 1.38 2015/09/11 17:24:09 christos Exp $
 .\"
 .\" Copyright (c) Christos Zoulas 2003.
 .\" All Rights Reserved.
@@ -25,7 +25,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd June 3, 2015
+.Dd September 11, 2015
 .Dt LIBMAGIC 3
 .Os
 .Sh NAME
@@ -291,6 +291,7 @@ library.
 .It Li MAGIC_PARAM_ELF_NOTES_MAX Ta size_t Ta 256
 .It Li MAGIC_PARAM_ELF_PHNUM_MAX Ta size_t Ta 128
 .It Li MAGIC_PARAM_ELF_SHNUM_MAX Ta size_t Ta 32768
+.It Li MAGIC_PARAM_REGEX_MAX Ta size_t Ta 8192
 .El
 .Pp
 The

diff --git a/src/apprentice.c b/src/apprentice.c
index 3eb1be03367ad6f4302c0eaa175f9432f8db4204..ad87fc030492efd50e5ea4874debd047d188186f 100644 (file)
--- a/src/apprentice.c
+++ b/src/apprentice.c
@@ -32,7 +32,7 @@
 #include "file.h"
 
 #ifndef        lint
-FILE_RCSID("@(#)$File: apprentice.c,v 1.236 2015/09/10 14:39:55 christos Exp $")
+FILE_RCSID("@(#)$File: apprentice.c,v 1.237 2015/09/11 17:24:09 christos Exp $")
 #endif /* lint */
 
 #include "magic.h"
@@ -531,6 +531,7 @@ file_ms_alloc(int flags)
        ms->elf_shnum_max = FILE_ELF_SHNUM_MAX;
        ms->elf_phnum_max = FILE_ELF_PHNUM_MAX;
        ms->elf_notes_max = FILE_ELF_NOTES_MAX;
+       ms->regex_max = FILE_REGEX_MAX;
        return ms;
 free:
        free(ms);

diff --git a/src/file.c b/src/file.c
index 15e1d540da9bf7f3462ac548406eb7cd5544b580..fa46b954abe54435908e2a937c15f596fc71c3a5 100644 (file)
--- a/src/file.c
+++ b/src/file.c
@@ -32,7 +32,7 @@
 #include "file.h"
 
 #ifndef        lint
-FILE_RCSID("@(#)$File: file.c,v 1.166 2015/09/08 13:46:49 christos Exp $")
+FILE_RCSID("@(#)$File: file.c,v 1.167 2015/09/11 17:24:09 christos Exp $")
 #endif /* lint */
 
 #include "magic.h"
@@ -131,6 +131,7 @@ private struct {
        { "elf_phnum",  MAGIC_PARAM_ELF_PHNUM_MAX, 0 },
        { "elf_shnum",  MAGIC_PARAM_ELF_SHNUM_MAX, 0 },
        { "elf_notes",  MAGIC_PARAM_ELF_NOTES_MAX, 0 },
+       { "regex",      MAGIC_PARAM_REGEX_MAX, 0 },
 };
 
 private char *progname;                /* used throughout              */

diff --git a/src/file.h b/src/file.h
index 6912e4df42f34e43fbab47676febfa727e85ba00..b0f0cc129c4e629dac5c933b3ec5bb4c2c9a6154 100644 (file)
--- a/src/file.h
+++ b/src/file.h
@@ -27,7 +27,7 @@
  */
 /*
  * file.h - definitions for file(1) program
- * @(#)$File: file.h,v 1.171 2015/08/30 14:16:33 christos Exp $
+ * @(#)$File: file.h,v 1.172 2015/09/11 17:24:09 christos Exp $
  */
 
 #ifndef __file_h__
@@ -415,11 +415,13 @@ struct magic_set {
        uint16_t elf_shnum_max;
        uint16_t elf_phnum_max;
        uint16_t elf_notes_max;
+       uint16_t regex_max;
 #define        FILE_INDIR_MAX                  15
 #define        FILE_NAME_MAX                   30
 #define        FILE_ELF_SHNUM_MAX              32768
 #define        FILE_ELF_PHNUM_MAX              2048
 #define        FILE_ELF_NOTES_MAX              256
+#define        FILE_REGEX_MAX                  8192
 };
 
 /* Type for Unicode characters */

diff --git a/src/magic.c b/src/magic.c
index 9a1c56dde304b5bc7dccc9a07fcbfae04005d0ef..87ac1cb0ae72d261dba5855137bfbc5bf1bb80df 100644 (file)
--- a/src/magic.c
+++ b/src/magic.c
@@ -33,7 +33,7 @@
 #include "file.h"
 
 #ifndef        lint
-FILE_RCSID("@(#)$File: magic.c,v 1.94 2015/07/11 14:41:37 christos Exp $")
+FILE_RCSID("@(#)$File: magic.c,v 1.95 2015/09/11 17:24:09 christos Exp $")
 #endif /* lint */
 
 #include "magic.h"
@@ -603,6 +603,9 @@ magic_setparam(struct magic_set *ms, int param, const void *val)
        case MAGIC_PARAM_ELF_NOTES_MAX:
                ms->elf_notes_max = (uint16_t)*(const size_t *)val;
                return 0;
+       case MAGIC_PARAM_REGEX_MAX:
+               ms->elf_notes_max = (uint16_t)*(const size_t *)val;
+               return 0;
        default:
                errno = EINVAL;
                return -1;
@@ -628,6 +631,9 @@ magic_getparam(struct magic_set *ms, int param, void *val)
        case MAGIC_PARAM_ELF_NOTES_MAX:
                *(size_t *)val = ms->elf_notes_max;
                return 0;
+       case MAGIC_PARAM_REGEX_MAX:
+               *(size_t *)val = ms->regex_max;
+               return 0;
        default:
                errno = EINVAL;
                return -1;

diff --git a/src/softmagic.c b/src/softmagic.c
index 4e2e2145a00b37ce791c7c7d4435394af1076107..84a893262c7b2d6d6f15daaa201b7cc33570dc66 100644 (file)
--- a/src/softmagic.c
+++ b/src/softmagic.c
@@ -32,7 +32,7 @@
 #include "file.h"
 
 #ifndef        lint
-FILE_RCSID("@(#)$File: softmagic.c,v 1.217 2015/07/27 09:08:10 christos Exp $")
+FILE_RCSID("@(#)$File: softmagic.c,v 1.218 2015/09/11 17:24:09 christos Exp $")
 #endif /* lint */
 
 #include "magic.h"
@@ -1102,6 +1102,8 @@ mcopy(struct magic_set *ms, union VALUETYPE *p, int type, int indir,
 
                        if (bytecnt == 0 || bytecnt > nbytes - offset)
                                bytecnt = nbytes - offset;
+                       if (bytecnt > ms->regex_max)
+                               bytecnt = ms->regex_max;
 
                        buf = RCAST(const char *, s) + offset;
                        end = last = RCAST(const char *, s) + bytecnt + offset;