Subject: Lack of bounds checking in vms-alpha.c parse_module
From: Alan Modra <[email-masked]>
Date: Mon, 12 Dec 2022 07:58:49 +0000 (+1030)

Lack of bounds checking in vms-alpha.c parse_module

	PR 29873
	PR 29874
	PR 29875
	PR 29876
	PR 29877
	PR 29878
	PR 29879
	PR 29880
	PR 29881
	PR 29882
	PR 29883
	PR 29884
	PR 29885
	PR 29886
	PR 29887
	PR 29888
	PR 29889
	PR 29890
	PR 29891
	* vms-alpha.c (parse_module): Make length param bfd_size_type.
	Delete length == -1 checks.  Sanity check record_length.
	Sanity check DST__K_MODBEG, DST__K_RTNBEG, DST__K_RTNEND lengths.
	Sanity check DST__K_SOURCE and DST__K_LINE_NUM elements
	before accessing.
	(build_module_list): Pass dst_section size to parse_module.

Upstream-Status: Backport [https://sourceware.org/git/?p=binutils-gdb.git;a=commitdiff_plain;h=77c225bdeb410cf60da804879ad41622f5f1aa44]

CVE: CVE-2023-25584

Signed-off-by: Deepthi Hemraj <[email-masked]>

---

diff --git a/bfd/vms-alpha.c b/bfd/vms-alpha.c
index c0eb5bc5a2a..3b63259cc81 100644
--- a/bfd/vms-alpha.c
+++ b/bfd/vms-alpha.c
@@ -4340,7 +4340,7 @@ new_module (bfd *abfd)

 static bool
 parse_module (bfd *abfd, struct module *module, unsigned char *ptr,
-	      int length)
+	      bfd_size_type length)
 {
   unsigned char *maxptr = ptr + length;
   unsigned char *src_ptr, *pcl_ptr;
@@ -4361,7 +4361,7 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,
     return false;
   module->line_table = curr_line;

-  while (length == -1 || (ptr + 3) < maxptr)
+  while (ptr + 3 < maxptr)
     {
       /* The first byte is not counted in the recorded length.  */
       int rec_length = bfd_getl16 (ptr) + 1;
@@ -4369,15 +4369,19 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,

       vms_debug2 ((2, "DST record: leng %d, type %d\n", rec_length, rec_type));

-      if (length == -1 && rec_type == DST__K_MODEND)
+      if (rec_length > maxptr - ptr)
+	break;
+      if (rec_type == DST__K_MODEND)
	break;

       switch (rec_type)
	{
	case DST__K_MODBEG:
+	  if (rec_length <= DST_S_B_MODBEG_NAME)
+	    break;
	  module->name
	    = _bfd_vms_save_counted_string (abfd, ptr + DST_S_B_MODBEG_NAME,
-					    maxptr - (ptr + DST_S_B_MODBEG_NAME));
+					    rec_length - DST_S_B_MODBEG_NAME);

	  curr_pc = 0;
	  prev_pc = 0;
@@ -4391,13 +4395,15 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,
	  break;

	case DST__K_RTNBEG:
+	  if (rec_length <= DST_S_B_RTNBEG_NAME)
+	    break;
	  funcinfo = (struct funcinfo *)
	    bfd_zalloc (abfd, sizeof (struct funcinfo));
	  if (!funcinfo)
	    return false;
	  funcinfo->name
	    = _bfd_vms_save_counted_string (abfd, ptr + DST_S_B_RTNBEG_NAME,
-					    maxptr - (ptr + DST_S_B_RTNBEG_NAME));
+					    rec_length - DST_S_B_RTNBEG_NAME);
	  funcinfo->low = bfd_getl32 (ptr + DST_S_L_RTNBEG_ADDRESS);
	  funcinfo->next = module->func_table;
	  module->func_table = funcinfo;
@@ -4407,6 +4413,8 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,
	  break;

	case DST__K_RTNEND:
+	  if (rec_length < DST_S_L_RTNEND_SIZE + 4)
+	    break;
	  if (!module->func_table)
	    return false;
	  module->func_table->high = module->func_table->low
@@ -4439,10 +4447,63 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,

	  vms_debug2 ((3, "source info\n"));

-	  while (src_ptr < ptr + rec_length)
+	  while (src_ptr - ptr < rec_length)
	    {
	      int cmd = src_ptr[0], cmd_length, data;

+	      switch (cmd)
+		{
+		case DST__K_SRC_DECLFILE:
+		  if (src_ptr - ptr + DST_S_B_SRC_DF_LENGTH >= rec_length)
+		    cmd_length = 0x10000;
+		  else
+		    cmd_length = src_ptr[DST_S_B_SRC_DF_LENGTH] + 2;
+		  break;
+
+		case DST__K_SRC_DEFLINES_B:
+		  cmd_length = 2;
+		  break;
+
+		case DST__K_SRC_DEFLINES_W:
+		  cmd_length = 3;
+		  break;
+
+		case DST__K_SRC_INCRLNUM_B:
+		  cmd_length = 2;
+		  break;
+
+		case DST__K_SRC_SETFILE:
+		  cmd_length = 3;
+		  break;
+
+		case DST__K_SRC_SETLNUM_L:
+		  cmd_length = 5;
+		  break;
+
+		case DST__K_SRC_SETLNUM_W:
+		  cmd_length = 3;
+		  break;
+
+		case DST__K_SRC_SETREC_L:
+		  cmd_length = 5;
+		  break;
+
+		case DST__K_SRC_SETREC_W:
+		  cmd_length = 3;
+		  break;
+
+		case DST__K_SRC_FORMFEED:
+		  cmd_length = 1;
+		  break;
+
+		default:
+		  cmd_length = 2;
+		  break;
+		}
+
+	      if (src_ptr - ptr + cmd_length > rec_length)
+		break;
+
	      switch (cmd)
		{
		case DST__K_SRC_DECLFILE:
@@ -4467,7 +4528,6 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,

		    module->file_table [fileid].name = filename;
		    module->file_table [fileid].srec = 1;
-		    cmd_length = src_ptr[DST_S_B_SRC_DF_LENGTH] + 2;
		    vms_debug2 ((4, "DST_S_C_SRC_DECLFILE: %d, %s\n",
				 fileid, module->file_table [fileid].name));
		  }
@@ -4484,7 +4544,6 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,
		  srec->sfile = curr_srec->sfile;
		  curr_srec->next = srec;
		  curr_srec = srec;
-		  cmd_length = 2;
		  vms_debug2 ((4, "DST_S_C_SRC_DEFLINES_B: %d\n", data));
		  break;

@@ -4499,14 +4558,12 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,
		  srec->sfile = curr_srec->sfile;
		  curr_srec->next = srec;
		  curr_srec = srec;
-		  cmd_length = 3;
		  vms_debug2 ((4, "DST_S_C_SRC_DEFLINES_W: %d\n", data));
		  break;

		case DST__K_SRC_INCRLNUM_B:
		  data = src_ptr[DST_S_B_SRC_UNSBYTE];
		  curr_srec->line += data;
-		  cmd_length = 2;
		  vms_debug2 ((4, "DST_S_C_SRC_INCRLNUM_B: %d\n", data));
		  break;

@@ -4514,21 +4571,18 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,
		  data = bfd_getl16 (src_ptr + DST_S_W_SRC_UNSWORD);
		  curr_srec->sfile = data;
		  curr_srec->srec = module->file_table[data].srec;
-		  cmd_length = 3;
		  vms_debug2 ((4, "DST_S_C_SRC_SETFILE: %d\n", data));
		  break;

		case DST__K_SRC_SETLNUM_L:
		  data = bfd_getl32 (src_ptr + DST_S_L_SRC_UNSLONG);
		  curr_srec->line = data;
-		  cmd_length = 5;
		  vms_debug2 ((4, "DST_S_C_SRC_SETLNUM_L: %d\n", data));
		  break;

		case DST__K_SRC_SETLNUM_W:
		  data = bfd_getl16 (src_ptr + DST_S_W_SRC_UNSWORD);
		  curr_srec->line = data;
-		  cmd_length = 3;
		  vms_debug2 ((4, "DST_S_C_SRC_SETLNUM_W: %d\n", data));
		  break;

@@ -4536,7 +4590,6 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,
		  data = bfd_getl32 (src_ptr + DST_S_L_SRC_UNSLONG);
		  curr_srec->srec = data;
		  module->file_table[curr_srec->sfile].srec = data;
-		  cmd_length = 5;
		  vms_debug2 ((4, "DST_S_C_SRC_SETREC_L: %d\n", data));
		  break;

@@ -4544,19 +4597,16 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,
		  data = bfd_getl16 (src_ptr + DST_S_W_SRC_UNSWORD);
		  curr_srec->srec = data;
		  module->file_table[curr_srec->sfile].srec = data;
-		  cmd_length = 3;
		  vms_debug2 ((4, "DST_S_C_SRC_SETREC_W: %d\n", data));
		  break;

		case DST__K_SRC_FORMFEED:
-		  cmd_length = 1;
		  vms_debug2 ((4, "DST_S_C_SRC_FORMFEED\n"));
		  break;

		default:
		  _bfd_error_handler (_("unknown source command %d"),
				      cmd);
-		  cmd_length = 2;
		  break;
		}

@@ -4569,18 +4619,114 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,

	  vms_debug2 ((3, "line info\n"));

-	  while (pcl_ptr < ptr + rec_length)
+	  while (pcl_ptr - ptr < rec_length)
	    {
	      /* The command byte is signed so we must sign-extend it.  */
	      int cmd = ((signed char *)pcl_ptr)[0], cmd_length, data;

+	      switch (cmd)
+		{
+		case DST__K_DELTA_PC_W:
+		  cmd_length = 3;
+		  break;
+
+		case DST__K_DELTA_PC_L:
+		  cmd_length = 5;
+		  break;
+
+		case DST__K_INCR_LINUM:
+		  cmd_length = 2;
+		  break;
+
+		case DST__K_INCR_LINUM_W:
+		  cmd_length = 3;
+		  break;
+
+		case DST__K_INCR_LINUM_L:
+		  cmd_length = 5;
+		  break;
+
+		case DST__K_SET_LINUM_INCR:
+		  cmd_length = 2;
+		  break;
+
+		case DST__K_SET_LINUM_INCR_W:
+		  cmd_length = 3;
+		  break;
+
+		case DST__K_RESET_LINUM_INCR:
+		  cmd_length = 1;
+		  break;
+
+		case DST__K_BEG_STMT_MODE:
+		  cmd_length = 1;
+		  break;
+
+		case DST__K_END_STMT_MODE:
+		  cmd_length = 1;
+		  break;
+
+		case DST__K_SET_LINUM_B:
+		  cmd_length = 2;
+		  break;
+
+		case DST__K_SET_LINUM:
+		  cmd_length = 3;
+		  break;
+
+		case DST__K_SET_LINUM_L:
+		  cmd_length = 5;
+		  break;
+
+		case DST__K_SET_PC:
+		  cmd_length = 2;
+		  break;
+
+		case DST__K_SET_PC_W:
+		  cmd_length = 3;
+		  break;
+
+		case DST__K_SET_PC_L:
+		  cmd_length = 5;
+		  break;
+
+		case DST__K_SET_STMTNUM:
+		  cmd_length = 2;
+		  break;
+
+		case DST__K_TERM:
+		  cmd_length = 2;
+		  break;
+
+		case DST__K_TERM_W:
+		  cmd_length = 3;
+		  break;
+
+		case DST__K_TERM_L:
+		  cmd_length = 5;
+		  break;
+
+		case DST__K_SET_ABS_PC:
+		  cmd_length = 5;
+		  break;
+
+		default:
+		  if (cmd <= 0)
+		    cmd_length = 1;
+		  else
+		    cmd_length = 2;
+		  break;
+		}
+
+	      if (pcl_ptr - ptr + cmd_length > rec_length)
+		break;
+
	      switch (cmd)
		{
		case DST__K_DELTA_PC_W:
		  data = bfd_getl16 (pcl_ptr + DST_S_W_PCLINE_UNSWORD);
		  curr_pc += data;
		  curr_linenum += 1;
-		  cmd_length = 3;
		  vms_debug2 ((4, "DST__K_DELTA_PC_W: %d\n", data));
		  break;

@@ -4588,131 +4734,111 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,
		  data = bfd_getl32 (pcl_ptr + DST_S_L_PCLINE_UNSLONG);
		  curr_pc += data;
		  curr_linenum += 1;
-		  cmd_length = 5;
		  vms_debug2 ((4, "DST__K_DELTA_PC_L: %d\n", data));
		  break;

		case DST__K_INCR_LINUM:
		  data = pcl_ptr[DST_S_B_PCLINE_UNSBYTE];
		  curr_linenum += data;
-		  cmd_length = 2;
		  vms_debug2 ((4, "DST__K_INCR_LINUM: %d\n", data));
		  break;

		case DST__K_INCR_LINUM_W:
		  data = bfd_getl16 (pcl_ptr + DST_S_W_PCLINE_UNSWORD);
		  curr_linenum += data;
-		  cmd_length = 3;
		  vms_debug2 ((4, "DST__K_INCR_LINUM_W: %d\n", data));
		  break;

		case DST__K_INCR_LINUM_L:
		  data = bfd_getl32 (pcl_ptr + DST_S_L_PCLINE_UNSLONG);
		  curr_linenum += data;
-		  cmd_length = 5;
		  vms_debug2 ((4, "DST__K_INCR_LINUM_L: %d\n", data));
		  break;

		case DST__K_SET_LINUM_INCR:
		  _bfd_error_handler
		    (_("%s not implemented"), "DST__K_SET_LINUM_INCR");
-		  cmd_length = 2;
		  break;

		case DST__K_SET_LINUM_INCR_W:
		  _bfd_error_handler
		    (_("%s not implemented"), "DST__K_SET_LINUM_INCR_W");
-		  cmd_length = 3;
		  break;

		case DST__K_RESET_LINUM_INCR:
		  _bfd_error_handler
		    (_("%s not implemented"), "DST__K_RESET_LINUM_INCR");
-		  cmd_length = 1;
		  break;

		case DST__K_BEG_STMT_MODE:
		  _bfd_error_handler
		    (_("%s not implemented"), "DST__K_BEG_STMT_MODE");
-		  cmd_length = 1;
		  break;

		case DST__K_END_STMT_MODE:
		  _bfd_error_handler
		    (_("%s not implemented"), "DST__K_END_STMT_MODE");
-		  cmd_length = 1;
		  break;

		case DST__K_SET_LINUM_B:
		  data = pcl_ptr[DST_S_B_PCLINE_UNSBYTE];
		  curr_linenum = data;
-		  cmd_length = 2;
		  vms_debug2 ((4, "DST__K_SET_LINUM_B: %d\n", data));
		  break;

		case DST__K_SET_LINUM:
		  data = bfd_getl16 (pcl_ptr + DST_S_W_PCLINE_UNSWORD);
		  curr_linenum = data;
-		  cmd_length = 3;
		  vms_debug2 ((4, "DST__K_SET_LINE_NUM: %d\n", data));
		  break;

		case DST__K_SET_LINUM_L:
		  data = bfd_getl32 (pcl_ptr + DST_S_L_PCLINE_UNSLONG);
		  curr_linenum = data;
-		  cmd_length = 5;
		  vms_debug2 ((4, "DST__K_SET_LINUM_L: %d\n", data));
		  break;

		case DST__K_SET_PC:
		  _bfd_error_handler
		    (_("%s not implemented"), "DST__K_SET_PC");
-		  cmd_length = 2;
		  break;

		case DST__K_SET_PC_W:
		  _bfd_error_handler
		    (_("%s not implemented"), "DST__K_SET_PC_W");
-		  cmd_length = 3;
		  break;

		case DST__K_SET_PC_L:
		  _bfd_error_handler
		    (_("%s not implemented"), "DST__K_SET_PC_L");
-		  cmd_length = 5;
		  break;

		case DST__K_SET_STMTNUM:
		  _bfd_error_handler
		    (_("%s not implemented"), "DST__K_SET_STMTNUM");
-		  cmd_length = 2;
		  break;

		case DST__K_TERM:
		  data = pcl_ptr[DST_S_B_PCLINE_UNSBYTE];
		  curr_pc += data;
-		  cmd_length = 2;
		  vms_debug2 ((4, "DST__K_TERM: %d\n", data));
		  break;

		case DST__K_TERM_W:
		  data = bfd_getl16 (pcl_ptr + DST_S_W_PCLINE_UNSWORD);
		  curr_pc += data;
-		  cmd_length = 3;
		  vms_debug2 ((4, "DST__K_TERM_W: %d\n", data));
		  break;

		case DST__K_TERM_L:
		  data = bfd_getl32 (pcl_ptr + DST_S_L_PCLINE_UNSLONG);
		  curr_pc += data;
-		  cmd_length = 5;
		  vms_debug2 ((4, "DST__K_TERM_L: %d\n", data));
		  break;

		case DST__K_SET_ABS_PC:
		  data = bfd_getl32 (pcl_ptr + DST_S_L_PCLINE_UNSLONG);
		  curr_pc = data;
-		  cmd_length = 5;
		  vms_debug2 ((4, "DST__K_SET_ABS_PC: 0x%x\n", data));
		  break;

@@ -4721,15 +4847,11 @@ parse_module (bfd *abfd, struct module *module, unsigned char *ptr,
		    {
		      curr_pc -= cmd;
		      curr_linenum += 1;
-		      cmd_length = 1;
		      vms_debug2 ((4, "bump pc to 0x%lx and line to %d\n",
				   (unsigned long)curr_pc, curr_linenum));
		    }
		  else
-		    {
-		      _bfd_error_handler (_("unknown line command %d"), cmd);
-		      cmd_length = 2;
-		    }
+		    _bfd_error_handler (_("unknown line command %d"), cmd);
		  break;
		}

@@ -4859,7 +4981,8 @@ build_module_list (bfd *abfd)
	return NULL;

       module = new_module (abfd);
-      if (!parse_module (abfd, module, PRIV (dst_section)->contents, -1))
+      if (!parse_module (abfd, module, PRIV (dst_section)->contents,
+			 PRIV (dst_section)->size))
	return NULL;
       list = module;
     }