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

1 files changed, 6 insertions, 3 deletions

diff --git a/contrib/elftoolchain/nm/nm.c b/contrib/elftoolchain/nm/nm.c
index 493f3a80b408..33ab44295c77 100644
--- a/contrib/elftoolchain/nm/nm.c
+++ b/contrib/elftoolchain/nm/nm.c
@@ -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) {