Commit d57b2b5b authored by Linus Torvalds's avatar Linus Torvalds
Browse files
Pull mount leak fix from Al Viro:
 "Regression fix for the syscalls-for-init series - fix a leak of a 'struct path'"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  fs: fix a struct path leak in path_umount
parents 049eb096 25ccd24f
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+18 −14
Original line number Diff line number Diff line
@@ -1706,34 +1706,38 @@ static inline bool may_mandlock(void)
}
#endif

int path_umount(struct path *path, int flags)
static int can_umount(const struct path *path, int flags)
{
	struct mount *mnt;
	int retval;
	struct mount *mnt = real_mount(path->mnt);

	if (flags & ~(MNT_FORCE | MNT_DETACH | MNT_EXPIRE | UMOUNT_NOFOLLOW))
		return -EINVAL;
	if (!may_mount())
		return -EPERM;

	mnt = real_mount(path->mnt);
	retval = -EINVAL;
	if (path->dentry != path->mnt->mnt_root)
		goto dput_and_out;
		return -EINVAL;
	if (!check_mnt(mnt))
		goto dput_and_out;
		return -EINVAL;
	if (mnt->mnt.mnt_flags & MNT_LOCKED) /* Check optimistically */
		goto dput_and_out;
	retval = -EPERM;
		return -EINVAL;
	if (flags & MNT_FORCE && !capable(CAP_SYS_ADMIN))
		goto dput_and_out;
		return -EPERM;
	return 0;
}

int path_umount(struct path *path, int flags)
{
	struct mount *mnt = real_mount(path->mnt);
	int ret;

	ret = can_umount(path, flags);
	if (!ret)
		ret = do_umount(mnt, flags);

	retval = do_umount(mnt, flags);
dput_and_out:
	/* we mustn't call path_put() as that would clear mnt_expiry_mark */
	dput(path->dentry);
	mntput_no_expire(mnt);
	return retval;
	return ret;
}

static int ksys_umount(char __user *name, int flags)