From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 06F743955CA; Sat, 3 Oct 2026 08:20:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791015634; cv=none; b=uA58D/KbZhBInZ9tjcArK8s4zhy5EdBIu6ztw1Nkg5tQhYc2W2CFnaBxC4VMtReF4Xwhi7XvXg9CwHFC8lGmmcN92a1Qd4fnMNt+ZE64b1mFvQIFGYIhcQWPX0bxS/KAa8Zj44NapEguyGyAUUB7RjNmSM4INoSljRE+jMpABbI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791015634; c=relaxed/simple; bh=mgxV3qK6cTr07AzQa0c+bJJ2Km8m7v2jxLNdsufVUTs=; h=Message-ID:Subject:From:To:Cc:Date:In-Reply-To:References: Content-Type:MIME-Version; b=qlEetyzQYK9dJWPE/GKK9SrJ7t5IFO3A6qcVyDfhyipMANnaFgIXamdqcj27408axGSr7HvYvXgCHpkG0aLkVAlzFcz9LTTnRrpnL+/jJAoKxrt2ruyrv2ruLuJ6W2xfetJ3UUlLHGg9rFb4zlaG1ep6bnjPKX63FWAyQ+gY2gg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NDaF7o82; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NDaF7o82" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5763E1F0089B; Sat, 3 Oct 2026 08:20:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791015630; bh=eWmsPsaqSJ6Vq6jvv3ugkIEDfSmRR0g0yKPOYeShMcU=; h=Subject:From:To:Cc:Date:In-Reply-To:References; b=NDaF7o82q+lHcA6tPpZ0zHsCI/mYQjSECgwygO34Cg2NeQjLvi4Z5vh80IR2gbLCm ceBpRneULbaz0kM+i7vIQMdTGtL1d86S4IUuVfIjoLY7YDIGwL7C8YW/jwMeqbxfGc RLjI2jNiG8YrFjF5xxdchsg3ewptkGxAkt4TEeBiQ+wVal7vV6DfL9Dq92r28HDlH9 ceIJ/DzzwDF9Vl0esmwkwn/qRA8DQiKnvxl3Mrk93U6hT5lYd3JASwk2gg9dpQYqP7 Y3if61dC0XZ4fZDvgBnc25Fc0cSagerGU+asViy7iU2fUPKuqmnKjFcFOtYQq3EKCb KKbGCYTpSuoKA== Message-ID: <21a3332f889994047f05caf7322d7a6ec30faf4e.camel@kernel.org> Subject: Re: [PATCH 18/21] nullfs: refuse leases and delegations From: Jeff Layton To: Christian Brauner , linux-fsdevel@vger.kernel.org Cc: Alexander Viro , Jan Kara , linux-kernel@vger.kernel.org, Jann Horn , Neil Brown , Amir Goldstein Date: Sat, 03 Oct 2026 09:20:25 +0100 In-Reply-To: <20261002-work-mount-fixes-4-v1-18-dd44b89d44ce@kernel.org> References: <20261002-work-mount-fixes-4-v1-0-dd44b89d44ce@kernel.org> <20261002-work-mount-fixes-4-v1-18-dd44b89d44ce@kernel.org> Autocrypt: addr=jlayton@kernel.org; prefer-encrypt=mutual; keydata=mQINBE6V0TwBEADXhJg7s8wFDwBMEvn0qyhAnzFLTOCHooMZyx7XO7dAiIhDSi7G1NPxw n8jdFUQMCR/GlpozMFlSFiZXiObE7sef9rTtM68ukUyZM4pJ9l0KjQNgDJ6Fr342Htkjxu/kFV1Wv egyjnSsFt7EGoDjdKqr1TS9syJYFjagYtvWk/UfHlW09X+jOh4vYtfX7iYSx/NfqV3W1D7EDi0PqV 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Fri, 2026-10-02 at 15:52 +0200, Christian Brauner wrote: > Refuse leases and delegations on nullfs as well. generic_setlease() > grants read leases and directory delegations on directories, so the > owner of the shared inode, or anyone with CAP_LEASE, could put one on > the directory that stands in for every unmounted mount and F_GETLEASE > and F_GETDELEG would show it to every other holder. Nothing on nullfs > ever changes, so a lease on it would never be broken and never tell > anyone anything. >=20 > Signed-off-by: Christian Brauner (Amutable) > --- > fs/nullfs.c | 8 ++++++++ > 1 file changed, 8 insertions(+) >=20 > diff --git a/fs/nullfs.c b/fs/nullfs.c > index d90c71f5eece..f76b87cf1841 100644 > --- a/fs/nullfs.c > +++ b/fs/nullfs.c > @@ -28,6 +28,13 @@ static int nullfs_nolock(struct file *file, int cmd, s= truct file_lock *fl) > return -ENOLCK; > } > =20 > +/* and no leases or delegations */ > +static int nullfs_nolease(struct file *file, int arg, struct file_lease = **flp, > + void **priv) > +{ > + return -EINVAL; > +} > + > /* what libfs gives an empty directory, plus the refusal of file locks *= / > static const struct file_operations nullfs_dir_operations =3D { > .llseek =3D nullfs_dir_llseek, > @@ -36,6 +43,7 @@ static const struct file_operations nullfs_dir_operatio= ns =3D { > .fsync =3D noop_fsync, > .lock =3D nullfs_nolock, > .flock =3D nullfs_nolock, > + .setlease =3D nullfs_nolease, > }; > =20 > static int nullfs_fs_fill_super(struct super_block *s, struct fs_context= *fc) I don't think this patch is necessary. Commit 2b10994be716 made it so that filesystems with a NULL ->setlease pointer already return -EINVAL. --=20 Jeff Layton