From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 369EA4F4CE6; Tue, 13 Oct 2026 12:02:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791892923; cv=none; b=Zc77JqJ4HwqDWOI0aqRXunAtmnHMSMZwt/KClbP2edj8WhOvTIgNiMMx1ApSqbjgu+fDhfMIryFr++Gin0Yl7NkkcJ7KVY3YDO1CC2QCj6lhOCDe6Ab4q2X7GzMwDG2sSG2Ew75UMdAsN1oeMegLEk3rky+NvNymTENMlmO0aXE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791892923; c=relaxed/simple; bh=9HgVSoGCLMXUJ/T19BLzwooIWEUFHILV7wWaRahGVPs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=kmBESA1Aam60JJhe5kff/zgi7AM5NgsoGjO9aqgG6iGtw5maXFRf0XbtiF898WVkYjd+wmfqShGu0Umrs6IO9unFV9g05GNU9djDBJ8+HjCTYM88YVT63geza3gTaEw3F8zzFjLisSM5J5HFa+XLVxmg9yVoQ/fRLN9igIv/ylI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rLRyzqO0; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="rLRyzqO0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D72D1F000FF; Tue, 13 Oct 2026 12:02:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791892922; bh=zqKBcP/Qls793kQg35rfNv6dqCn+AdixnoDMsyg98s0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=rLRyzqO0RsbPpseM+vtdD47S9IGSg99YamnqJ2FFyg/QfVxin6QVE3uC6CDdV1EBc MgYEGIllwJQHvXvENPudLtOrRwfL+UW32G4ioGjFB619eWlr7mUMkng2KRHUnXPctg qdO2Cw2s3yUWF/O4x12QNDwuLeD0s3sdvroYOcnw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Stephen Smalley , Paul Moore Subject: [PATCH 6.18 052/621] selinux: preserve NATIVE_LABELS on already-initialized sb in set_mnt_opts Date: Tue, 13 Oct 2026 13:30:47 +0200 Message-ID: <20261013112922.098256936@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261013112920.855194808@linuxfoundation.org> References: <20261013112920.855194808@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-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 @@ -686,8 +686,12 @@ 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); @@ -731,6 +735,9 @@ 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; }