Merge tag 'execve-v6.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull execve fixes from Kees Cook:

 - Fix an ancient signal action copy race (Bernd Edlinger)

 - Fix a memory leak in ELF loader, when under memory pressure (Li
   Zetao)

* tag 'execve-v6.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  fs/binfmt_elf: Fix memory leak in load_elf_binary()
  exec: Copy oldsighand->action under spin-lock

fs/binfmt_elf.c

@@ -911,7 +911,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
 		interp_elf_ex = kmalloc(sizeof(*interp_elf_ex), GFP_KERNEL);
 		if (!interp_elf_ex) {
 			retval = -ENOMEM;
-			goto out_free_ph;
+			goto out_free_file;
 		}
 
 		/* Get the exec headers */
@@ -1354,6 +1354,7 @@ static int load_elf_binary(struct linux_binprm *bprm)
 out_free_dentry:
 	kfree(interp_elf_ex);
 	kfree(interp_elf_phdata);
+out_free_file:
 	allow_write_access(interpreter);
 	if (interpreter)
 		fput(interpreter);

fs/exec.c

@@ -1197,11 +1197,11 @@ static int unshare_sighand(struct task_struct *me)
 			return -ENOMEM;
 
 		refcount_set(&newsighand->count, 1);
-		memcpy(newsighand->action, oldsighand->action,
-		       sizeof(newsighand->action));
 
 		write_lock_irq(&tasklist_lock);
 		spin_lock(&oldsighand->siglock);
+		memcpy(newsighand->action, oldsighand->action,
+		       sizeof(newsighand->action));
 		rcu_assign_pointer(me->sighand, newsighand);
 		spin_unlock(&oldsighand->siglock);
 		write_unlock_irq(&tasklist_lock);