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 8B6913D810C; Tue, 16 Jun 2026 18:27:09 +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=1781634430; cv=none; b=VQgIRDf2qSN/LYa4kOytT5E+/SyPdS4VSHiC3tGuSZPOQuvnsCmqeMp824qSXRKM/Joe8ugFlwp3KcsXwIxWS0JJpD8OdDk+P15Qa2hr8CZWfkZ3hve43NAM54F11G/OAP3ikBRJI0ZfAQaUrFsBhn1f3FXTlWuLyw8OPcDxR7M= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781634430; c=relaxed/simple; bh=Bx01kfMQNsN5smiB5vKM1sEmGkolduXCnfVyTW8cFF4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=B36+RYx+bsGlHgrymZ+WTTUYEcA+YvobQSG+Lj5LlUcjtHv3D7mkBnEpkCkGbvvis4ZOmEh68I5rDvSgJcni5WZHaSFcSuT13iCgAyXTUjExRBxKshnqJjBUBrVIAkOawyTyBJB8PUuXphV+KCkmI4ywOzRcwG6R3MprqKI3XSk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rjdevBBC; 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="rjdevBBC" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E90A1F000E9; Tue, 16 Jun 2026 18:27:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781634429; bh=P9iOOJjksyMIYTTkGRPgyKMpqGT/tZs7Qx+JfnaWQh4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=rjdevBBCSLJ0gbMywTHj7ujeRt4KUU+lFai7CTCp5tXvfW7bfFiXXUbuPqKcYeJBr HWY74lBhekvLAg9H8kqEHvwv6gekCzMOuciBI9K4RJqtYazVxEVcrGTYO7zNRlQZzc 4PF2zmza14jRSrN+koAXLiFrEoZbL0yIpV7AC2sU= 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 5.15 220/411] fuse: reject fuse_notify() pagecache ops on directories Date: Tue, 16 Jun 2026 20:27:38 +0530 Message-ID: <20260616145112.487388117@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145100.376842714@linuxfoundation.org> References: <20260616145100.376842714@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: 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 @@ -1599,6 +1599,10 @@ 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; @@ -1770,7 +1774,10 @@ 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);