Commit 8861fd57 authored by Al Viro's avatar Al Viro
Browse files

binfmt_flat: don't use __put_user() 



... and check the return value

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent 0abb013e

fs/binfmt_flat.c

+14 −8
Original line number Diff line number Diff line
@@ -138,35 +138,40 @@ static int create_flat_tables(struct linux_binprm *bprm, unsigned long arg_start 
	current->mm->start_stack = (unsigned long)sp & -FLAT_STACK_ALIGN;

	sp = (unsigned long __user *)current->mm->start_stack;



	__put_user(bprm->argc, sp++);

	if (put_user(bprm->argc, sp++))

		return -EFAULT;

	if (IS_ENABLED(CONFIG_BINFMT_FLAT_ARGVP_ENVP_ON_STACK)) {

		unsigned long argv, envp;

		argv = (unsigned long)(sp + 2);

		envp = (unsigned long)(sp + 2 + bprm->argc + 1);

		__put_user(argv, sp++);

		__put_user(envp, sp++);

		if (put_user(argv, sp++) || put_user(envp, sp++))

			return -EFAULT;

	}



	current->mm->arg_start = (unsigned long)p;

	for (i = bprm->argc; i > 0; i--) {

		__put_user((unsigned long)p, sp++);

		if (put_user((unsigned long)p, sp++))

			return -EFAULT;

		len = strnlen_user(p, MAX_ARG_STRLEN);

		if (!len || len > MAX_ARG_STRLEN)

			return -EINVAL;

		p += len;

	}

	__put_user(0, sp++);

	if (put_user(0, sp++))

		return -EFAULT;

	current->mm->arg_end = (unsigned long)p;



	current->mm->env_start = (unsigned long) p;

	for (i = bprm->envc; i > 0; i--) {

		__put_user((unsigned long)p, sp++);

		if (put_user((unsigned long)p, sp++))

			return -EFAULT;

		len = strnlen_user(p, MAX_ARG_STRLEN);

		if (!len || len > MAX_ARG_STRLEN)

			return -EINVAL;

		p += len;

	}

	__put_user(0, sp++);

	if (put_user(0, sp++))

		return -EFAULT;

	current->mm->env_end = (unsigned long)p;



	return 0;
@@ -998,7 +1003,8 @@ static int load_flat_binary(struct linux_binprm *bprm) 
			unsigned long __user *sp;

			current->mm->start_stack -= sizeof(unsigned long);

			sp = (unsigned long __user *)current->mm->start_stack;

			__put_user(start_addr, sp);

			if (put_user(start_addr, sp))

				return -EFAULT;

			start_addr = libinfo.lib_list[i].entry;

		}

	}