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 DB98F29B76D; Mon, 5 May 2025 22:19:31 +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=1746483572; cv=none; b=SaPL3+AdKkNCI7TlipN+vI4U8JtNPP4Fc5BHFxBjhC6J9pVgT90kkcDpvb9EvRL4ozJ19t9/Ysfr5es5oMckzZqBBoomScvsIr8gBJRxJx29NEnVY+29Z29bvnhi1/w2/0mtN7Ju2mrcO4ceuOlKgiofr8SHQKkVu/hETE9+170= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746483572; c=relaxed/simple; bh=IFxjyUy9p939cgdSn8JtjShI/xj2DKazY5LneB9PH38=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=s259EbCl8/Di3iQik0V35sH87fjdsvB3zcUyL+pgAERkiiFyOoClDZWP2E5mGjFEPNUoWBVhinZ2j3D5aQ5gJ37JjvImENkgm/+Yc7/au85z0yZsdvcYlANdTZav31VSQkgqURosxLqABPs3ROrE0tOZoZTFlFlfz8n0jwS5dbU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=E4oRdLJD; 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="E4oRdLJD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 45D0EC4CEED; Mon, 5 May 2025 22:19:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746483571; bh=IFxjyUy9p939cgdSn8JtjShI/xj2DKazY5LneB9PH38=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=E4oRdLJD9Wlm66hosFcyEg9GqHnl9lGyINiiu29kCdpbXEXSzduXwBJyKmysljHzt ZveqT4UTGiepuo0NjWsnBUf0MvyZ0Q7gni9UGrfrKGBm6ziWFRKJfAJpTuq3+Zehef j8k1Xuo2trgqu8PQdnGWhdb9jFkWmsaRRZ981Z1kCF39ObV9TVMcRbzzfT/ZtlLW5i sgALH11Ar7EWgql8BQCwurV9XKnWkUGxcQ6Zozr0mIcdpOOPObvKmTzmjaEZYcLGmZ pH5sTHj0uux4qLCYySOGaTUYlEA1G3tBvVgYGhCrBT1Nk17T2BT8RMwmLEvFFHsC7x 6N07io0fWpgmQ== 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 6.14 120/642] ext4: reorder capability check last Date: Mon, 5 May 2025 18:05:36 -0400 Message-Id: <20250505221419.2672473-120-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505221419.2672473-1-sashal@kernel.org> References: <20250505221419.2672473-1-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 6.14.5 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 8042ad8738089..c48fd36b2d74c 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -649,8 +649,8 @@ 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