svn commit: r342575 - head/usr.bin/ar

[Ed Maste]

Author: emaste
Date: Fri Dec 28 17:00:12 2018
New Revision: 342575
URL: https://svnweb.freebsd.org/changeset/base/342575

Log:
  ar: detect and error out on 32-bit symbol table overflow
  
  BSD ar currently does not support the /SYM64/ 64-bit symbol table, and
  previously truncated to 32-bits, silently producing corrupted archives
  larger than 4GB.
  
  Note that this is only a partial fix; additional checks will come.
  
  PR:		234454
  Reported by:	Aijaz Baig, imp
  MFC after:	2 weeks
  Sponsored by:	The FreeBSD Foundation

Modified:
  head/usr.bin/ar/write.c

Modified: head/usr.bin/ar/write.c
==============================================================================
--- head/usr.bin/ar/write.c	Fri Dec 28 16:08:49 2018	(r342574)
+++ head/usr.bin/ar/write.c	Fri Dec 28 17:00:12 2018	(r342575)
@@ -659,9 +659,13 @@ write_objs(struct bsdar *bsdar)
 		pm_sz = _ARMAG_LEN + (_ARHDR_LEN + s_sz);
 		if (bsdar->as != NULL)
 			pm_sz += _ARHDR_LEN + bsdar->as_sz;
-		for (i = 0; (size_t)i < bsdar->s_cnt; i++)
+		for (i = 0; (size_t)i < bsdar->s_cnt; i++) {
+			if (*(bsdar->s_so + i) > UINT32_MAX - pm_sz)
+				bsdar_errc(bsdar, EX_SOFTWARE, 0,
+				    "Symbol table offset overflow");
 			*(bsdar->s_so + i) = htobe32(*(bsdar->s_so + i) +
 			    pm_sz);
+		}
 	}
 
 	if ((a = archive_write_new()) == NULL)