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 EDE6A3BA89A; Mon, 5 May 2025 23:22:24 +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=1746487345; cv=none; b=Lx8NrPJ4zNYabNKwO+3rC2omfwWO9jfHyb4U6giWelR266nuA6KQD68+Qtk7VJdVBjykxbWvNwJBXiuH9dosYmkc5zh6RiaEWUirylBXGWcKgsppWyVu0JNeEYk2nuaeXcWtlbW+e9CAMP47h/DBL0LCsiLTGrANzfQj/0yXQc4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746487345; c=relaxed/simple; bh=AFK/OQ0OUylW3kDlFFn7G+WF7ksViGgUTGH+b4cqYfg=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=T9oUcVkeZWQxankRbeH2ZEBuxOeTcFnrNNup69Z2v9YtMfLUwTdFkHJN2jgYCBMVzLtbjIamdUd0fIMSUveKMCOy3PYSyGJbjtbpR6IWOJl8tERWK5MxdLuSJP2FWa09mye6Mye5jmvL84nXQ/1vicawu+DIuyudHjNy6G8qd2I= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Zea7wgyc; 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="Zea7wgyc" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 543F1C4CEEE; Mon, 5 May 2025 23:22:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746487344; bh=AFK/OQ0OUylW3kDlFFn7G+WF7ksViGgUTGH+b4cqYfg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Zea7wgych5rVnyVPI+LBsLUYcNyex0GKvMsvs5+DrLzW9mMUYKCVKj7a5yLIKDLuU zwyiFkJpTRmRamvE9//TfmTMGGegd/f/poac6Sjwpz8lNRA4hgaooiXKhC6S4WAT0+ zrpBWNnwCp+pglmrf+HkBRRgMjoGjDTxXMAqbZ1IDR3uDLrWCgdDF3FvSvJO5GNxY1 zg/siYruPUkHwi/6j8jMCsLeYT5fVKLAbppZnwwHmnkdDEKav8OrP98iTfhA788UkA SJCl9lS8BWfdUZJC4Rt03KRpa4TTIwhOSLpwbqO4sXkmIOLSFRHOmGoS97oeoZHNFV 8mwoIBQ5f3pOw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: =?UTF-8?q?Christian=20G=C3=B6ttsche?= , Serge Hallyn , Jan Kara , Theodore Ts'o , Sasha Levin , adilger.kernel@dilger.ca, linux-ext4@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 18/79] ext4: reorder capability check last Date: Mon, 5 May 2025 19:20:50 -0400 Message-Id: <20250505232151.2698893-18-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505232151.2698893-1-sashal@kernel.org> References: <20250505232151.2698893-1-sashal@kernel.org> 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 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.4.293 Content-Transfer-Encoding: 8bit From: Christian Göttsche [ Upstream commit 1b419c889c0767a5b66d0a6c566cae491f1cb0f7 ] capable() calls refer to enabled LSMs whether to permit or deny the request. This is relevant in connection with SELinux, where a capability check results in a policy decision and by default a denial message on insufficient permission is issued. It can lead to three undesired cases: 1. A denial message is generated, even in case the operation was an unprivileged one and thus the syscall succeeded, creating noise. 2. To avoid the noise from 1. the policy writer adds a rule to ignore those denial messages, hiding future syscalls, where the task performs an actual privileged operation, leading to hidden limited functionality of that task. 3. To avoid the noise from 1. the policy writer adds a rule to permit the task the requested capability, while it does not need it, violating the principle of least privilege. Signed-off-by: Christian Göttsche Reviewed-by: Serge Hallyn Reviewed-by: Jan Kara Link: https://patch.msgid.link/20250302160657.127253-2-cgoettsche@seltendoof.de Signed-off-by: Theodore Ts'o Signed-off-by: Sasha Levin --- fs/ext4/balloc.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index b68cee75f5c58..a32eb67a8f0e2 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -609,8 +609,8 @@ static int ext4_has_free_clusters(struct ext4_sb_info *sbi, /* Hm, nope. Are (enough) root reserved clusters available? */ if (uid_eq(sbi->s_resuid, current_fsuid()) || (!gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) && in_group_p(sbi->s_resgid)) || - capable(CAP_SYS_RESOURCE) || - (flags & EXT4_MB_USE_ROOT_BLOCKS)) { + (flags & EXT4_MB_USE_ROOT_BLOCKS) || + capable(CAP_SYS_RESOURCE)) { if (free_clusters >= (nclusters + dirty_clusters + resv_clusters)) -- 2.39.5