From patchwork Wed Sep 1 16:27:19 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 505527 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1A723C4320A for ; Wed, 1 Sep 2021 16:29:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F07FD61057 for ; Wed, 1 Sep 2021 16:29:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245215AbhIAQaF (ORCPT ); Wed, 1 Sep 2021 12:30:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:45286 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245504AbhIAQ3L (ORCPT ); Wed, 1 Sep 2021 12:29:11 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 079C761056; Wed, 1 Sep 2021 16:28:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1630513694; bh=33RC3YogqXCC1E17dtW915hQmiG+ogGdN4NtjjBgfzA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nyxQjtLrs90M6GAWph90hPlvdMFzKjH2KAoFIwP1D1AkzcHjsfaeH2KVIN3a/G6MT xgCSYFRZQ886bKtiJFyL2XACl1ZJd/wTg4boEuzxBIpBrcylVwlnwWVYlOf/lgxn6M 1f/d36rVX9dd6LsPzeqm+dpbmjobDUf9oZRKtqNrQWcxAg5OejsyYMemVEdx3zsUzu vdJTmaa5JdQkfNnHk8gikDvxKyr2osbzTPlStvfae7tXtFvSHntMQKtFN5IZqtTh4J yhr4A5uupXYmPBxEj2s4O33RlAXPdJbzzJY6FgrVDgkiB6atixbf7IAmt59tCOYRsF xBp6PDYJIRakg== From: Eric Biggers To: stable@vger.kernel.org Cc: linux-fscrypt@vger.kernel.org Subject: [PATCH 5.10 2/4] ext4: report correct st_size for encrypted symlinks Date: Wed, 1 Sep 2021 09:27:19 -0700 Message-Id: <20210901162721.138605-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210901162721.138605-1-ebiggers@kernel.org> References: <20210901162721.138605-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Biggers commit 8c4bca10ceafc43b1ca0a9fab5fa27e13cbce99e upstream. The stat() family of syscalls report the wrong size for encrypted symlinks, which has caused breakage in several userspace programs. Fix this by calling fscrypt_symlink_getattr() after ext4_getattr() for encrypted symlinks. This function computes the correct size by reading and decrypting the symlink target (if it's not already cached). For more details, see the commit which added fscrypt_symlink_getattr(). Fixes: f348c252320b ("ext4 crypto: add symlink encryption") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210702065350.209646-3-ebiggers@kernel.org Signed-off-by: Eric Biggers --- fs/ext4/symlink.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/ext4/symlink.c b/fs/ext4/symlink.c index dd05af983092d..a9457fed351ed 100644 --- a/fs/ext4/symlink.c +++ b/fs/ext4/symlink.c @@ -52,10 +52,19 @@ static const char *ext4_encrypted_get_link(struct dentry *dentry, return paddr; } +static int ext4_encrypted_symlink_getattr(const struct path *path, + struct kstat *stat, u32 request_mask, + unsigned int query_flags) +{ + ext4_getattr(path, stat, request_mask, query_flags); + + return fscrypt_symlink_getattr(path, stat); +} + const struct inode_operations ext4_encrypted_symlink_inode_operations = { .get_link = ext4_encrypted_get_link, .setattr = ext4_setattr, - .getattr = ext4_getattr, + .getattr = ext4_encrypted_symlink_getattr, .listxattr = ext4_listxattr, };