[binutils-gdb] Yet another ecoff fuzzed object fix

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=6fc018e9e593a3235dbf7026726ba4665373b741

commit 6fc018e9e593a3235dbf7026726ba4665373b741
Author: Alan Modra <amodra@gmail.com>
Date:   Mon Jun 5 16:21:25 2023 +0930

    Yet another ecoff fuzzed object fix
    
            * ecoff.c (_bfd_ecoff_slurp_symbol_table): Sanity check fdr_ptr
            csym against remaining space for symbols.  Error on out of bounds
            fdr_ptr fields.

Diff:
---
 bfd/ecoff.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/bfd/ecoff.c b/bfd/ecoff.c
index c4c2e530be0..573f52d0299 100644
--- a/bfd/ecoff.c
+++ b/bfd/ecoff.c
@@ -956,13 +956,19 @@ _bfd_ecoff_slurp_symbol_table (bfd *abfd)
       char *lraw_end;
       HDRR *symhdr = &ecoff_data (abfd)->debug_info.symbolic_header;
 
+      if (fdr_ptr->csym == 0)
+	continue;
       if (fdr_ptr->isymBase < 0
 	  || fdr_ptr->isymBase > symhdr->isymMax
-	  || fdr_ptr->csym <= 0
-	  || fdr_ptr->csym > symhdr->isymMax - fdr_ptr->isymBase
+	  || fdr_ptr->csym < 0
+	  || fdr_ptr->csym > ((long) bfd_get_symcount (abfd)
+			      - (internal_ptr - internal))
 	  || fdr_ptr->issBase < 0
 	  || fdr_ptr->issBase > symhdr->issMax)
-	continue;
+	{
+	  bfd_set_error (bfd_error_bad_value);
+	  return false;
+	}
       lraw_src = ((char *) ecoff_data (abfd)->debug_info.external_sym
 		  + fdr_ptr->isymBase * external_sym_size);
       lraw_end = lraw_src + fdr_ptr->csym * external_sym_size;