ar: Check elf_getahdr doesn't return NULL

When elf_getahdr returns NULL we shouldn't even try to handle the ar
header, but immediately go to the next entry.

	* src/ar.c (do_oper_extract): If elf_getahdr goto next.
	(do_oper_delete): Likewise.
	(do_oper_insert): Likewise.

Suggested-by: Anton Moryakov <[email protected]>
Signed-off-by: Mark Wielaard <[email protected]>

1 files changed, 6 insertions, 0 deletions

diff --git a/src/ar.c b/src/ar.c
index 9ace28b9..03118c4e 100644
--- a/src/ar.c
+++ b/src/ar.c
@@ -498,6 +498,8 @@ do_oper_extract (int oper, const char *arfname, char **argv, int argc,
   while ((subelf = elf_begin (fd, cmd, elf)) != NULL)
     {
       Elf_Arhdr *arhdr = elf_getarhdr (subelf);
+      if (arhdr == NULL)
+	goto next;
 
       if (strcmp (arhdr->ar_name, "/") == 0)
 	{
@@ -943,6 +945,8 @@ do_oper_delete (const char *arfname, char **argv, int argc,
   while ((subelf = elf_begin (fd, cmd, elf)) != NULL)
     {
       Elf_Arhdr *arhdr = elf_getarhdr (subelf);
+      if (arhdr == NULL)
+	goto next;
 
       /* Ignore the symbol table and the long file name table here.  */
       if (strcmp (arhdr->ar_name, "/") == 0
@@ -1152,6 +1156,8 @@ do_oper_insert (int oper, const char *arfname, char **argv, int argc,
   while ((subelf = elf_begin (fd, cmd, elf)) != NULL)
     {
       Elf_Arhdr *arhdr = elf_getarhdr (subelf);
+      if (arhdr == NULL)
+	goto next;
 
       /* Ignore the symbol table and the long file name table here.  */
       if (strcmp (arhdr->ar_name, "/") == 0