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 CACB93A9627; Tue, 16 Jun 2026 16:06:54 +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=1781626015; cv=none; b=sDZHZr8UYX9J1VecqIzQVs6gVeke23R2/uHbeIoPWzmTUwlJeLUPwQfvo/E89iCgxKKWGlVCiN7WlXoDTo/diYtoK01rZLjrN2ROmkmDLAj4MqKzZL9iaabd+4DgXsEx2+dbaWk4WtqUitT+p+iWycjUUdISHgp95N+Hc6bIx4I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781626015; c=relaxed/simple; bh=Nblf+abPAV8QKe7K8udCU5zGOl9GlMXwSXxEWlFe0NE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=etCdWtjtNAqNcP1ZWzPfyXH07s/K2n36VO/f2SIFcDwre2oy1awnZcYzUIVtpi2hTXVzcFhbakuiPRaAE+ax8YhYGe/YgUI6wSMzhUYFn6n9k0+Grd2ABgPWgLP68uNMNBBL2h4yVQP+xmAcC6aLfIRoLM3mfeAsXktXHKG7ZSg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=RmiY7tpB; 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="RmiY7tpB" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C90751F000E9; Tue, 16 Jun 2026 16:06:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781626014; bh=vL8e/zg9bYvvngSJU+qZzKXmLCVfjyfGVgpuORr15ts=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=RmiY7tpBI72tE1RflvcsBWUcCx3wxEwTkOSEde13hNhmtE1TU3mRjzPJO7JSOG7R1 b4psPCw3bLbCJac29hvrVjuQR5FiTJ00LTLQz0S3biC818dcCTWbW4Irwzsq1fUfSA /W3k9jfSNFAfrBRyaCxRUaIVeuZIW48t+LraNgEY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jann Horn , Miklos Szeredi , "Christian Brauner (Amutable)" Subject: [PATCH 6.18 217/325] fuse: reject fuse_notify() pagecache ops on directories Date: Tue, 16 Jun 2026 20:30:13 +0530 Message-ID: <20260616145108.986891337@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145057.827196531@linuxfoundation.org> References: <20260616145057.827196531@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: Jann Horn commit 9c954499d43aefac01c5dfb57a82b13d2dcf4b94 upstream. The operations FUSE_NOTIFY_STORE and FUSE_NOTIFY_RETRIEVE allow the FUSE daemon to actively write/read pagecache contents. For directories with FOPEN_CACHE_DIR, the pagecache is used as kernel-internal cache storage, and userspace is not supposed to have direct access to this cache - in particular, fuse_parse_cache() will hit WARN_ON() if the cache contains bogus data. Reject FUSE_NOTIFY_STORE and FUSE_NOTIFY_RETRIEVE on anything other than regular files with -EINVAL. Fixes: 5d7bc7e8680c ("fuse: allow using readdir cache") Cc: stable@vger.kernel.org Signed-off-by: Jann Horn Link: https://patch.msgid.link/20260519-fuse-dir-pagecache-v2-1-5428fa48e175@google.com Acked-by: Miklos Szeredi Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Greg Kroah-Hartman --- fs/fuse/dev.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1798,6 +1798,10 @@ static int fuse_notify_store(struct fuse inode = fuse_ilookup(fc, nodeid, NULL); if (!inode) goto out_up_killsb; + if (!S_ISREG(inode->i_mode)) { + err = -EINVAL; + goto out_iput; + } mapping = inode->i_mapping; index = outarg.offset >> PAGE_SHIFT; @@ -1977,7 +1981,10 @@ static int fuse_notify_retrieve(struct f inode = fuse_ilookup(fc, nodeid, &fm); if (inode) { - err = fuse_retrieve(fm, inode, &outarg); + if (!S_ISREG(inode->i_mode)) + err = -EINVAL; + else + err = fuse_retrieve(fm, inode, &outarg); iput(inode); } up_read(&fc->killsb);