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 58F133D301E; Mon, 17 Aug 2026 14:39:02 +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=1786977543; cv=none; b=HX7y3AoAAETbEh0NjsM2GIuIS0s34Xaigdwq110LuYw5lxCiYM4GZobxIPz2DsMHTSVFFSfBzicvWAPKHZyqhmdEfI5PffgDznsrV/jtQXVCCYn/Y79d/lhBjD6k4XX0JfkzkAAi/JGpk1rFNBlE3iqmvMWt26lLANHWwvOKX8s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786977543; c=relaxed/simple; bh=QDVsbKDBSwpNcvAQUd3GwnYX32zjPqmW4Z1QP1GPaTQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Mm1jK7q2L4RYomyOG2pn8gqwtQStZp3xIyNnIxxlYMtBZFqhV8hYu/E37U+Mmzp1bFclGQXwIY7nwprU/9gpNRPXGc0pDGgVCose8PYoqEH4vvG+deGKjgNLoyeAqIU9SOcMnkCoGwDnVaiZr8y3O40Nekedizpa+dmb193cp14= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=joRo1bx8; 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="joRo1bx8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DCC401F000E9; Mon, 17 Aug 2026 14:39:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786977542; bh=sqPx0yMl31q2aMnW7ADvwY10N2zegqQpr8Jqnc18lyY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=joRo1bx83kYin94LBLGyIcd+1cBvGGJkzh8r/u5j7IbxubzE1WFhMFYXdY/d06XgS hif/aV4x/lu5dL1D1nt+Cwg9hb0UDQ8imtaQDh/EGn13UmBzCS7/f6WT3UuxlCM7ig OmF1omOGmifvjzeZEi+pH0Vx0BYT90jqz1/ZlEz8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Denis Arefev , Al Viro , "Christian Brauner (Amutable)" , Sasha Levin Subject: [PATCH 5.15 366/456] mount: honour SB_NOUSER in the new mount API Date: Mon, 17 Aug 2026 15:32:36 +0200 Message-ID: <20260817132553.809223765@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132539.792407575@linuxfoundation.org> References: <20260817132539.792407575@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Al Viro [ Upstream commit 6dd3c6884cd9defb511284b566cef5ac8f657dbf ] One should *not* be allowed to mount one of those, new API or not. Reported-by: Denis Arefev Signed-off-by: Al Viro Link: https://patch.msgid.link/20260602020444.GP2636677@ZenIV Signed-off-by: Christian Brauner (Amutable) [Denis: rename new_mnt -> newmount.mnt] [Denis: use goto err_unlock instead of direct return] Signed-off-by: Denis Arefev Signed-off-by: Sasha Levin --- fs/namespace.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/fs/namespace.c b/fs/namespace.c index ae1b8530eb939..2c502d554f619 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -3700,6 +3700,11 @@ SYSCALL_DEFINE3(fsmount, int, fs_fd, unsigned int, flags, ret = PTR_ERR(newmount.mnt); goto err_unlock; } + if (newmount.mnt->mnt_sb->s_flags & SB_NOUSER) { + mntput(newmount.mnt); + ret = -EINVAL; + goto err_unlock; + } newmount.dentry = dget(fc->root); newmount.mnt->mnt_flags = mnt_flags; -- 2.53.0