From mboxrd@z Thu Jan 1 00:00:00 1970 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 6C6C228E8 for ; Tue, 17 Jun 2025 15:45:32 +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=1750175132; cv=none; b=d04uSgFMET8dzoDygZ/xJMHnkjn2kjNyxqpN2EWesf6lTR4cnRKGupSlehzqxGY2qW6ncAp1W8+n/gUbVDDk84TE7Q7ARpvHL5ATXsfCcP1a4MnyiyUc8Oci6shdJi6vI6TQs2LBJziPfTU4t1XEIzz/eL0wmkCvwC6YAxJgDJw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750175132; c=relaxed/simple; bh=TzgQ817oPideW0OGeNJ7vQIt1tyMrwmwsKZLNhBpMZk=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=RJtL2quGzCCGWh/4MFP+1siuNL+WyHEavnnJbhzxVi9z4UpzsDI6QMecbchxtgoRfsBWR05bfHMj/IWRvNB6MZt01z6dfrBodJRnlCf8r3JWlDzUkBBUSTzP181FCEkaGldyFAVSibmK4cmZkFMdOXNgzQKtCMyGfN+pnk/+YBc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=JumJ1Xns; 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="JumJ1Xns" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BD68BC4CEE3; Tue, 17 Jun 2025 15:45:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1750175132; bh=TzgQ817oPideW0OGeNJ7vQIt1tyMrwmwsKZLNhBpMZk=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=JumJ1XnsmUd9TsSMZiPs+buLS3csI9s00wRQ9V14PbFxFWtgoMjVjBp2xb55ViH1w 307rXgg5YngUk7qQzmm+ogeXcHg4ZY6b8/18al2LDBc1gCcLF/JW+R75+tfa7E7F5w xRVlEjDWrk5Tj+6BR0VFrkfEQ30fzMk3vH/0I6f+r9L1KYFYNgGWj+IEn+9L0ehj+5 ld+AWbcVbMdVcOjNSsA08lwB3tnFQ3l8+KUm6EeK5b7CLaoWXnSqMPGx92hLACWXaA qyPRRRepo192gF7DZPOaMfx+y/qktwMZdTXOkDl35zp1rp2Mgs2FLuGVVeVfIQjXEs BevBVxCADKAGg== From: Christian Brauner Date: Tue, 17 Jun 2025 17:45:13 +0200 Subject: [PATCH RFC 3/7] pidfs: raise SB_I_NODEV and SB_I_NOEXEC Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20250617-work-pidfs-xattr-v1-3-d9466a20da2e@kernel.org> References: <20250617-work-pidfs-xattr-v1-0-d9466a20da2e@kernel.org> In-Reply-To: <20250617-work-pidfs-xattr-v1-0-d9466a20da2e@kernel.org> To: linux-fsdevel@vger.kernel.org Cc: Jann Horn , Josef Bacik , Jeff Layton , Daan De Meyer , Lennart Poettering , Mike Yuan , =?utf-8?q?Zbigniew_J=C4=99drzejewski-Szmek?= , Christian Brauner , Alexander Mikhalitsyn X-Mailer: b4 0.15-dev-262a7 X-Developer-Signature: v=1; a=openpgp-sha256; l=858; i=brauner@kernel.org; h=from:subject:message-id; bh=TzgQ817oPideW0OGeNJ7vQIt1tyMrwmwsKZLNhBpMZk=; b=owGbwMvMwCU28Zj0gdSKO4sYT6slMWQE9k7kDTt7OzPzaLhOKJvnYbNpKa1Kd0UPHa4sYm1h+ VzTkLSro5SFQYyLQVZMkcWh3SRcbjlPxWajTA2YOaxMIEMYuDgFYCIGFYwMj5hF3K2FTF8cmM38 9Yz4lm+SAUztR149+rQ45Mj37ecZORj+ZynsmWQ4SZBZ4XBMY8DlxzMW8p88butVfcztYKzLrYO b+QE= X-Developer-Key: i=brauner@kernel.org; a=openpgp; fpr=4880B8C9BD0E5106FC070F4F7B3C391EFEA93624 Similar to commit 1ed95281c0c7 ("anon_inode: raise SB_I_NODEV and SB_I_NOEXEC"): it shouldn't be possible to execute pidfds via execveat(fd_anon_inode, "", NULL, NULL, AT_EMPTY_PATH) so raise SB_I_NOEXEC so that no one gets any creative ideas. Also raise SB_I_NODEV as we don't expect or support any devices on pidfs. Signed-off-by: Christian Brauner --- fs/pidfs.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/pidfs.c b/fs/pidfs.c index ca217bfe6e40..1343bfc60e3f 100644 --- a/fs/pidfs.c +++ b/fs/pidfs.c @@ -959,6 +959,8 @@ static int pidfs_init_fs_context(struct fs_context *fc) if (!ctx) return -ENOMEM; + fc->s_iflags |= SB_I_NOEXEC; + fc->s_iflags |= SB_I_NODEV; ctx->ops = &pidfs_sops; ctx->eops = &pidfs_export_operations; ctx->dops = &pidfs_dentry_operations; -- 2.47.2