From nobody Thu Oct 2 19:24:12 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 F158A2D238A; Fri, 12 Sep 2025 11:53:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757677986; cv=none; b=MbDLg9IME9U5kJGW/xIrhCBSjENFeCrVN4iaX+jrapFakCpzBwx+HoNQVVS0gHbt8VRZIsOKAuhaJQhUZTjvtzLe83FpZErBcAn604DqOl3pkeIdJwp4mztBhPquAHFsnCy93PyZhN5VbEu5Ceq3G4WOtcIZ7a31RmZvT6WzIcY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757677986; c=relaxed/simple; bh=o5M10bc2KTaMvy47wLA0T02mOeZELPiisrkVC9gcmAk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=YiNTGYrzt3TCO0ca8EkO7t2l7kVC700G1WnjkuC01UGcoPCaR8YiHRNvMII1/vByUkWYbMoRwnOQ3k4YYIviM9y3JVNt0cKxHoP9Vx0X6+1WHjW+dg6oVZRjIUVf3hmjKENSzh4F8b/GzNWHVmHAeDQrZkHNeVh6TVGG9gnIeuU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OgV69ipU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="OgV69ipU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63687C4CEFA; Fri, 12 Sep 2025 11:53:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1757677985; bh=o5M10bc2KTaMvy47wLA0T02mOeZELPiisrkVC9gcmAk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=OgV69ipUU8XTMnx+7emxEuWLrbUpLE481qs0/Ba9zX4VGge+g8I43uXOFmCx6UBS8 J6pkpwqtIBNIlhu5m5MMzDwXDVeirvnfqKTTYfJ0isU9LmHw1V2K1J1CVNyB3wk06q l/f3dDf70upvFfsy1hMFNsaO+w3AFhr0bgj3fw8B/1gyCpDyqljUZzFOugAx/ME0qw MnQjrWq0MXd8xdJRxttNQVc46LfrS0GsHdErLqHMOSzWvV1dH8V1rm/Q/5vINtkRte XtwwkM7oJ9oNJhuZBcgfof+FFCxX2otJ7CjHkgdvkPUzKNTGOIDJAf/gye+hkI12I1 lpl76USDLGx/A== From: Christian Brauner Date: Fri, 12 Sep 2025 13:52:24 +0200 Subject: [PATCH v2 01/33] pidfs: validate extensible ioctls Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Message-Id: <20250912-work-namespace-v2-1-1a247645cef5@kernel.org> References: <20250912-work-namespace-v2-0-1a247645cef5@kernel.org> In-Reply-To: <20250912-work-namespace-v2-0-1a247645cef5@kernel.org> To: Jan Kara , Amir Goldstein , linux-fsdevel@vger.kernel.org Cc: Josef Bacik , Jeff Layton , Mike Yuan , =?utf-8?q?Zbigniew_J=C4=99drzejewski-Szmek?= , Lennart Poettering , Daan De Meyer , Aleksa Sarai , Alexander Viro , Jens Axboe , Tejun Heo , Johannes Weiner , =?utf-8?q?Michal_Koutn=C3=BD?= , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Chuck Lever , linux-nfs@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, netdev@vger.kernel.org, Christian Brauner X-Mailer: b4 0.14.3-dev-385fa X-Developer-Signature: v=1; a=openpgp-sha256; l=1527; i=brauner@kernel.org; h=from:subject:message-id; bh=o5M10bc2KTaMvy47wLA0T02mOeZELPiisrkVC9gcmAk=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWQc4Zyyeq1o6p7v4bHpT3xFPqixaFtNCDm+PEaVd93xl qoKN+2/HaUsDGJcDLJiiiwO7Sbhcst5KjYbZWrAzGFlAhnCwMUpABPh1GP47/DJa2fB9sJ594pW 1W9t4VD+mPyh12K9kErmnX0uB44WBjIyXM/6Vf7KIJdf+HGlikjxsvQ0w77853x6Z75OsrSsfeD JAgA= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Validate extensible ioctls stricter than we do now. Reviewed-by: Aleksa Sarai Reviewed-by: Jan Kara Signed-off-by: Christian Brauner --- fs/pidfs.c | 2 +- include/linux/fs.h | 14 ++++++++++++++ 2 files changed, 15 insertions(+), 1 deletion(-) diff --git a/fs/pidfs.c b/fs/pidfs.c index edc35522d75c..0a5083b9cce5 100644 --- a/fs/pidfs.c +++ b/fs/pidfs.c @@ -440,7 +440,7 @@ static bool pidfs_ioctl_valid(unsigned int cmd) * erronously mistook the file descriptor for a pidfd. * This is not perfect but will catch most cases. */ - return (_IOC_TYPE(cmd) =3D=3D _IOC_TYPE(PIDFD_GET_INFO)); + return extensible_ioctl_valid(cmd, PIDFD_GET_INFO, PIDFD_INFO_SIZE_VER0); } =20 return false; diff --git a/include/linux/fs.h b/include/linux/fs.h index d7ab4f96d705..2f2edc53bf3c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -4023,4 +4023,18 @@ static inline bool vfs_empty_path(int dfd, const cha= r __user *path) =20 int generic_atomic_write_valid(struct kiocb *iocb, struct iov_iter *iter); =20 +static inline bool extensible_ioctl_valid(unsigned int cmd_a, + unsigned int cmd_b, size_t min_size) +{ + if (_IOC_DIR(cmd_a) !=3D _IOC_DIR(cmd_b)) + return false; + if (_IOC_TYPE(cmd_a) !=3D _IOC_TYPE(cmd_b)) + return false; + if (_IOC_NR(cmd_a) !=3D _IOC_NR(cmd_b)) + return false; + if (_IOC_SIZE(cmd_a) < min_size) + return false; + return true; +} + #endif /* _LINUX_FS_H */ --=20 2.47.3