From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793213266; b=lad2lLCyegz3IlG2a1OdCh8LvJZ5ZEMdNVSL56eCslWr7V3hoIEKYZYfZ+e9gIDiawzg JpQr9PPvMYnu+Zwj1zWNDxC6uejikMSiXlBDBgjS84EW5JW+6Th02CuOmaraiFrS0GEZy YFfSmF+AOoB7CPzB/v/VDGCQaFhd1yUvX7nXK9yuw0kJQEDOPdw9h+vcn2ZtvPYwRTyd+ 1P3jvXDkajgcwCl+QFbPqno1sQUWV1gslmrUi6gjed0ExyzL5cvDb4i1HBX4AET9g57I5 6Rvte/Q/OHaYevSQb3pqsbUUouShBZeY3+czD9uDdp+Ys/3690Zgv76MKRuszVlnccg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793213266; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=/XUD/t8XP4Sst3z5UxcGxFlSrfL3hDD3EIm1BTGkbQ8=; b=RuqNcCQnEqEbeivbnEF24c5Kyv/iXbvIJ9geNoU96w75W2RG3EDTguePUFByJ2qS6MjC 8bNFeJQSdUe7ybr//rV90I2VnU+mseBoA8PQT+DdJls5aJZ8K8s1MiN5QiaET0UgxIk0W 2FIS03TjSTxBjMX6M5xTTPojjX18+ZpEIvo/TIZHJwX9mMxqxhR2M/cxt8IED6qclDp9X d8hHcDIcFbWRaT8gQLigqAz/Ge3/vt1xdHxeRQBPF1A6C/za5lGtNyeWFqu5kcdVmCiKW Ns2z1xFmqHPN+GgWgUUdj9wAwPoM43yZpicnM74XIjHT/2bG6bIeEHSxmNjGxpR49iw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=l7qsifVt; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2AAC4606A31E; Wed, 28 Oct 2026 18:47:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=l7qsifVt Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7B8141F01825; Wed, 28 Oct 2026 18:47:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793213266; bh=/XUD/t8XP4Sst3z5UxcGxFlSrfL3hDD3EIm1BTGkbQ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=l7qsifVt7hXjgBlxadNkqVWSPg2XZe3UaAs7QnCUok7urBd0kJmWJQJo0BWR+IJhM 6nmcJJxzyVi160HA++vKm3lHXry8ix+KASMqjXi4Lz/N4FuOSlO8RXxIH2dsQfu9t2 nc7JBrET9RmIbAxjQJrTbIiJYUwdyuEotZRj3lpY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stephen Smalley , Paul Moore Subject: [PATCH 6.1 0446/1887] selinux: preserve NATIVE_LABELS on already-initialized sb in set_mnt_opts Date: Wed, 28 Oct 2026 17:42:22 +0100 Message-ID: <20261028170509.380464403@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261028170459.200466217@linuxfoundation.org> References: <20261028170459.200466217@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Stephen Smalley commit 28b7260548af3d35773477993ad4e4de41578dd7 upstream. When an NFSv4 filesystem exported with security_label is mounted a second time, sget_fc() returns the existing superblock and nfs_get_root() calls security_sb_set_mnt_opts() again on it. Since the superblock is already SB_INITIALIZED, selinux_set_mnt_opts() takes an early exit without setting SECURITY_LSM_NATIVE_LABELS in *set_kern_flags. nfs_get_root() then sees kflags without SECURITY_LSM_NATIVE_LABELS set and clears NFS_CAP_SECURITY_LABEL on the shared nfs_server, silently disabling per-file labeling for both the new and the original mount. Commit 3815a245b501 ("security/selinux: fix SECURITY_LSM_NATIVE_LABELS on reused superblock") fixed the same problem in selinux_sb_clone_mnt_opts(). The reused-superblock path for a plain second mount now goes through sb_set_mnt_opts rather than sb_clone_mnt_opts, so it needs the same treatment: on both SE_SBINITIALIZED early exits, set SECURITY_LSM_NATIVE_LABELS in *set_kern_flags when the superblock was already using SECURITY_FS_USE_NATVE. Cc: stable@vger.kernel.org Closes: https://github.com/SELinuxProject/selinux-kernel/issues/69 Closes: https://github.com/SELinuxProject/selinux-kernel/issues/70 Closes: https://github.com/SELinuxProject/selinux-testsuite/issues/91 Closes: https://github.com/SELinuxProject/selinux-testsuite/issues/92 Fixes: eb9ae686507b ("SELinux: Add new labeling type native labels") Signed-off-by: Stephen Smalley Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman --- security/selinux/hooks.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -646,8 +646,12 @@ static int selinux_set_mnt_opts(struct s * will be used for both mounts) */ if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA) - && !opts) + && !opts) { + if ((kern_flags & SECURITY_LSM_NATIVE_LABELS) && + sbsec->behavior == SECURITY_FS_USE_NATIVE) + *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; goto out; + } root_isec = backing_inode_security_novalidate(root); @@ -691,6 +695,9 @@ static int selinux_set_mnt_opts(struct s /* previously mounted with options, but not on this attempt? */ if ((sbsec->flags & SE_MNTMASK) && !opts) goto out_double_mount; + if ((kern_flags & SECURITY_LSM_NATIVE_LABELS) && + sbsec->behavior == SECURITY_FS_USE_NATIVE) + *set_kern_flags |= SECURITY_LSM_NATIVE_LABELS; rc = 0; goto out; }