asan: Buffer overflow in evax_bfd_print_dst

asan: Buffer overflow in evax_bfd_print_dst

[Alan Modra]

With "name" a char*, the length at name[0] might be negative, escaping
buffer limit checks.

	* vms-alpha.c (evax_bfd_print_dst): Make name an unsigned char*.
	(evax_bfd_print_emh): Likewise.

diff --git a/bfd/vms-alpha.c b/bfd/vms-alpha.c
index 06fa891ac70..4a92574c850 100644
--- a/bfd/vms-alpha.c
+++ b/bfd/vms-alpha.c
@@ -5939,9 +5939,9 @@ evax_bfd_print_emh (FILE *file, unsigned char *rec, unsigned int rec_len)
     case EMH__C_MHD:
       {
 	struct vms_emh_mhd *mhd = (struct vms_emh_mhd *) rec;
-	const char * name;
-	const char * nextname;
-	const char * maxname;
+	unsigned char *name;
+	unsigned char *nextname;
+	unsigned char *maxname;
 
 	/* PR 21840: Check for invalid lengths.  */
 	if (rec_len < sizeof (* mhd))
@@ -5953,8 +5953,8 @@ evax_bfd_print_emh (FILE *file, unsigned char *rec, unsigned int rec_len)
 	fprintf (file, _("   structure level: %u\n"), mhd->strlvl);
 	fprintf (file, _("   max record size: %u\n"),
 		 (unsigned) bfd_getl32 (mhd->recsiz));
-	name = (char *)(mhd + 1);
-	maxname = (char *) rec + rec_len;
+	name = (unsigned char *) (mhd + 1);
+	maxname = (unsigned char *) rec + rec_len;
 	if (name > maxname - 2)
 	  {
 	    fprintf (file, _("   Error: The module name is missing\n"));
@@ -7397,7 +7397,7 @@ evax_bfd_print_dst (struct bfd *abfd, unsigned int dst_size, FILE *file)
 	case DST__K_MODBEG:
 	  {
 	    struct vms_dst_modbeg *dst = (void *)buf;
-	    const char *name = (const char *)buf + sizeof (*dst);
+	    unsigned char *name = buf + sizeof (*dst);
 
 	    fprintf (file, _("modbeg\n"));
 	    if (len < sizeof (*dst))
@@ -7421,7 +7421,7 @@ evax_bfd_print_dst (struct bfd *abfd, unsigned int dst_size, FILE *file)
 		    name += name[0] + 1;
 		    nlen = len - 1;
 		    fprintf (file, _("   compiler   : %.*s\n"),
-			     name[0] > nlen ? nlen: name[0], name + 1);
+			     name[0] > nlen ? nlen : name[0], name + 1);
 		  }
 	      }
 	  }
@@ -7432,7 +7432,7 @@ evax_bfd_print_dst (struct bfd *abfd, unsigned int dst_size, FILE *file)
 	case DST__K_RTNBEG:
 	  {
 	    struct vms_dst_rtnbeg *dst = (void *)buf;
-	    const char *name = (const char *)buf + sizeof (*dst);
+	    unsigned char *name = buf + sizeof (*dst);
 
 	    fputs (_("rtnbeg\n"), file);
 	    if (len >= sizeof (*dst))
@@ -7485,7 +7485,7 @@ evax_bfd_print_dst (struct bfd *abfd, unsigned int dst_size, FILE *file)
 	case DST__K_BLKBEG:
 	  {
 	    struct vms_dst_blkbeg *dst = (void *)buf;
-	    const char *name = (const char *)buf + sizeof (*dst);
+	    unsigned char *name = buf + sizeof (*dst);
 
 	    if (len > sizeof (*dst))
 	      {
@@ -7536,7 +7536,7 @@ evax_bfd_print_dst (struct bfd *abfd, unsigned int dst_size, FILE *file)
 	case DST__K_RECBEG:
 	  {
 	    struct vms_dst_recbeg *recbeg = (void *)buf;
-	    const char *name = (const char *)buf + sizeof (*recbeg);
+	    unsigned char *name = buf + sizeof (*recbeg);
 
 	    if (len > sizeof (*recbeg))
 	      {
@@ -7750,7 +7750,7 @@ evax_bfd_print_dst (struct bfd *abfd, unsigned int dst_size, FILE *file)
 		  case DST__K_SRC_DECLFILE:
 		    {
 		      struct vms_dst_src_decl_src *src = (void *) buf;
-		      const char *name;
+		      unsigned char *name;
 		      int nlen;
 
 		      if (len < sizeof (*src))
@@ -7772,7 +7772,7 @@ evax_bfd_print_dst (struct bfd *abfd, unsigned int dst_size, FILE *file)
 		      if (src->length > len || src->length <= sizeof (*src))
 			break;
 		      nlen = src->length - sizeof (*src) - 1;
-		      name = (const char *) buf + sizeof (*src);
+		      name = buf + sizeof (*src);
 		      fprintf (file, _("   filename   : %.*s\n"),
 			       name[0] > nlen ? nlen : name[0], name + 1);
 		      if (name[0] >= nlen)

-- 
Alan Modra
Australia Development Lab, IBM