[binutils-gdb] readelf: catch archive_file_size of -1

[Alan Modra]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=237877b8183a23ecc889b5c796c210aac9cfb742

commit 237877b8183a23ecc889b5c796c210aac9cfb742
Author: Alan Modra <amodra@gmail.com>
Date:   Fri Jul 30 13:07:12 2021 +0930

    readelf: catch archive_file_size of -1
    
    Fuzzers might put -1 in arhdr.ar_size.  If the size is rounded up to
    and even number of bytes we get zero.
    
            * readelf.c (process_archive): Don't round up archive_file_size.
            Do round up next_arhdr_offset calculation.

Diff:
---
 binutils/readelf.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/binutils/readelf.c b/binutils/readelf.c
index 5682837ed7b..bd16fcc77ad 100644
--- a/binutils/readelf.c
+++ b/binutils/readelf.c
@@ -21789,8 +21789,6 @@ process_archive (Filedata * filedata, bool is_thin_archive)
       arch.next_arhdr_offset += sizeof arch.arhdr;
 
       filedata->archive_file_size = strtoul (arch.arhdr.ar_size, NULL, 10);
-      if (filedata->archive_file_size & 01)
-	++filedata->archive_file_size;
 
       name = get_archive_member_name (&arch, &nested_arch);
       if (name == NULL)
@@ -21894,7 +21892,7 @@ process_archive (Filedata * filedata, bool is_thin_archive)
 	  filedata->file_name = qualified_name;
 	  if (! process_object (filedata))
 	    ret = false;
-	  arch.next_arhdr_offset += filedata->archive_file_size;
+	  arch.next_arhdr_offset += (filedata->archive_file_size + 1) & -2;
 	  /* Stop looping with "negative" archive_file_size.  */
 	  if (arch.next_arhdr_offset < filedata->archive_file_size)
 	    arch.next_arhdr_offset = -1ul;