[PATCH] x86_64: Check for bad elf entry address.

Fixes a local DOS on Intel systems that lead to an endless
recursive fault.  AMD machines don't seem to be affected.
Signed-off-by: NSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

fs/binfmt_elf.c

@@ -938,6 +938,11 @@ static int load_elf_binary(struct linux_binprm * bprm, struct pt_regs * regs)
 		kfree(elf_interpreter);
 	} else {
 		elf_entry = loc->elf_ex.e_entry;
+		if (BAD_ADDR(elf_entry)) {
+			send_sig(SIGSEGV, current, 0);
+			retval = -ENOEXEC; /* Nobody gets to see this, but.. */
+			goto out_free_dentry;
+		}
 	}
 
 	kfree(elf_phdata);