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 EFCC3299512; Mon, 5 May 2025 22:42:35 +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=1746484957; cv=none; b=rtnOmTf4QYAC0vqC4Qt2pZTxWkxdZ9AdECHZvwibdU2ZI9DtSV7yBCJQoxz5V5YfHHuuENbly9iQ43JMdlGp6+OMt9qPZvpWUqjEo0aP2xIWm+CluP+jATPN3gKu+Y2vw2CO9ptptDu8DSf1vA4xFKv9e2CGVKrvd2kN0ynbB4k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1746484957; c=relaxed/simple; bh=IFxjyUy9p939cgdSn8JtjShI/xj2DKazY5LneB9PH38=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version:Content-Type; b=GdKiWHeiNXAwL2KHyp48rGKF2Y4eweoSFpk26QrSkfdjZx+IwhjbK7qqXUcGohIS/7YEAavPeTOxsvu8iyB59a25i08BdDLRSEGreHFWBl+lNBqflm1crf3gkHFESIterbmoFm2qDMm8SQCbuN2PwPS3Q92b4YEnVmoC1cxlrB0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=txlV3Jd4; 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="txlV3Jd4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CFE14C4CEF1; Mon, 5 May 2025 22:42:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1746484955; bh=IFxjyUy9p939cgdSn8JtjShI/xj2DKazY5LneB9PH38=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=txlV3Jd4iSQqHQrncond5Z6YvFtiBAKjyYalXB1PDBLJbARVFALVUnSYKncqpXjPZ KfyUpnSpSZkjTKGXUR8ns/XEUBGOH7pNujay4R2yphANFXQ8gLw72Bh/uRQZhdJ8/X xW/z37V91eiktZ8U3h1Szet1MiiQ6ffGJKLITIKbjCy1qqV1AUzIMLapBTELHSU15Z 1OSt+GfSHw7jF0TpNfql5pBWTQjtUvVcFDPgKU2RT6SEoY8GydRprLX9bn6VdesMKw eQNnmy+lCXeSbxxJyuiQrcnCKqGPrMQug+k+x42A8pnClOxyh//PWe4hNCR29QMi5L yzamakSwdPdLw== 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 6.12 094/486] ext4: reorder capability check last Date: Mon, 5 May 2025 18:32:50 -0400 Message-Id: <20250505223922.2682012-94-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250505223922.2682012-1-sashal@kernel.org> References: <20250505223922.2682012-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@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 6.12.26 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