svn commit: r331078 - head/contrib/elftoolchain/nm

[Conrad Meyer]

Author: cem
Date: Fri Mar 16 22:25:33 2018
New Revision: 331078
URL: https://svnweb.freebsd.org/changeset/base/331078

Log:
  elftoolchain nm(1): Initialize allocated memory before use
  
  In out of memory scenarios (where one of these allocations failed but
  other(s) did not), nm(1) could reference the uninitialized value of these
  allocations (undefined behavior).
  
  Always initialize any successful allocations as the most expedient
  resolution of the issue.  However, I would encourage upstream elftoolchain
  contributors to clean up the error path to just abort immediately, rather
  than proceeding sloppily when one allocation fails.
  
  Reported by:	Coverity
  Sponsored by:	Dell EMC Isilon

Modified:
  head/contrib/elftoolchain/nm/nm.c

Modified: head/contrib/elftoolchain/nm/nm.c
==============================================================================
--- head/contrib/elftoolchain/nm/nm.c	Fri Mar 16 22:23:04 2018	(r331077)
+++ head/contrib/elftoolchain/nm/nm.c	Fri Mar 16 22:25:33 2018	(r331078)
@@ -1310,14 +1310,17 @@ read_elf(Elf *elf, const char *filename, Elf_Kind kind
 	line_info = malloc(sizeof(struct line_info_head));
 	func_info = malloc(sizeof(struct func_info_head));
 	var_info = malloc(sizeof(struct var_info_head));
+	if (line_info != NULL)
+		SLIST_INIT(line_info);
+	if (func_info != NULL)
+		SLIST_INIT(func_info);
+	if (var_info != NULL)
+		SLIST_INIT(var_info);
 	if (line_info == NULL || func_info == NULL || var_info == NULL) {
 		warn("malloc");
 		(void) dwarf_finish(dbg, &de);
 		goto process_sym;
 	}
-	SLIST_INIT(line_info);
-	SLIST_INIT(func_info);
-	SLIST_INIT(var_info);
 
 	while ((ret = dwarf_next_cu_header(dbg, NULL, NULL, NULL, NULL, NULL,
 	    &de)) ==  DW_DLV_OK) {