From patchwork Wed Sep 8 21:50:30 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 508757 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=-24.4 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING, 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 79039C4332F for ; Wed, 8 Sep 2021 21:51:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6259761166 for ; Wed, 8 Sep 2021 21:51:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235447AbhIHVwi (ORCPT ); Wed, 8 Sep 2021 17:52:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:38278 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235595AbhIHVwh (ORCPT ); Wed, 8 Sep 2021 17:52:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B055861102; Wed, 8 Sep 2021 21:51:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631137888; bh=OQTsB/jVGcQ7Wx3XSHynFYsRG7N4x/1YxYJzvlQNDMI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=IVxoJfrQX5DygB+Ym+3nvCCQsgrYaVVmNBmE26tQ3HdynZPian1la1QFCHrC1pov8 GuqkPsPFgQAz9mwfXOhEUmDKUytXH9CRf5++voXm/X6Y84NexBzZdj/xJCxUQjxDpW 3xfrrCzhNx37wiJDoZTqNhPzx+mfL5fALqujig0UCibDA8wy10IOSqr1EAOnr6n3Oj VPlmvWl/eUbfA6ZEcTokQIfEaD8N679qKg5U+JXvd5M/EUmAtSbeW/FDAlw1Ow1/gL 0eXr2BxtH8hQpomzQWpBBAfZZUzz7LZ9MKQAvAosQUwl5mOmORGuSZ4eIGx56Q0ia3 AGKtVLsP9wHkA== From: Eric Biggers To: stable@vger.kernel.org Cc: linux-fscrypt@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org Subject: [PATCH 1/4] fscrypt: add fscrypt_symlink_getattr() for computing st_size Date: Wed, 8 Sep 2021 14:50:30 -0700 Message-Id: <20210908215033.1122580-2-ebiggers@kernel.org> X-Mailer: git-send-email 2.33.0.153.gba50c8fa24-goog In-Reply-To: <20210908215033.1122580-1-ebiggers@kernel.org> References: <20210908215033.1122580-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Biggers commit d18760560593e5af921f51a8c9b64b6109d634c2 upstream. Add a helper function fscrypt_symlink_getattr() which will be called from the various filesystems' ->getattr() methods to read and decrypt the target of encrypted symlinks in order to report the correct st_size. Detailed explanation: As required by POSIX and as documented in various man pages, st_size for a symlink is supposed to be the length of the symlink target. Unfortunately, st_size has always been wrong for encrypted symlinks because st_size is populated from i_size from disk, which intentionally contains the length of the encrypted symlink target. That's slightly greater than the length of the decrypted symlink target (which is the symlink target that userspace usually sees), and usually won't match the length of the no-key encoded symlink target either. This hadn't been fixed yet because reporting the correct st_size would require reading the symlink target from disk and decrypting or encoding it, which historically has been considered too heavyweight to do in ->getattr(). Also historically, the wrong st_size had only broken a test (LTP lstat03) and there were no known complaints from real users. (This is probably because the st_size of symlinks isn't used too often, and when it is, typically it's for a hint for what buffer size to pass to readlink() -- which a slightly-too-large size still works for.) However, a couple things have changed now. First, there have recently been complaints about the current behavior from real users: - Breakage in rpmbuild: https://github.com/rpm-software-management/rpm/issues/1682 https://github.com/google/fscrypt/issues/305 - Breakage in toybox cpio: https://www.mail-archive.com/toybox@lists.landley.net/msg07193.html - Breakage in libgit2: https://issuetracker.google.com/issues/189629152 (on Android public issue tracker, requires login) Second, we now cache decrypted symlink targets in ->i_link. Therefore, taking the performance hit of reading and decrypting the symlink target in ->getattr() wouldn't be as big a deal as it used to be, since usually it will just save having to do the same thing later. Also note that eCryptfs ended up having to read and decrypt symlink targets in ->getattr() as well, to fix this same issue; see commit 3a60a1686f0d ("eCryptfs: Decrypt symlink target for stat size"). So, let's just bite the bullet, and read and decrypt the symlink target in ->getattr() in order to report the correct st_size. Add a function fscrypt_symlink_getattr() which the filesystems will call to do this. (Alternatively, we could store the decrypted size of symlinks on-disk. But there isn't a great place to do so, and encryption is meant to hide the original size to some extent; that property would be lost.) Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210702065350.209646-2-ebiggers@kernel.org Signed-off-by: Eric Biggers --- fs/crypto/hooks.c | 44 +++++++++++++++++++++++++++++++++ include/linux/fscrypt_notsupp.h | 6 +++++ include/linux/fscrypt_supp.h | 1 + 3 files changed, 51 insertions(+) diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c index aa86cb2db823..ae7a413c0bdd 100644 --- a/fs/crypto/hooks.c +++ b/fs/crypto/hooks.c @@ -279,3 +279,47 @@ const char *fscrypt_get_symlink(struct inode *inode, const void *caddr, return ERR_PTR(err); } EXPORT_SYMBOL_GPL(fscrypt_get_symlink); + +/** + * fscrypt_symlink_getattr() - set the correct st_size for encrypted symlinks + * @path: the path for the encrypted symlink being queried + * @stat: the struct being filled with the symlink's attributes + * + * Override st_size of encrypted symlinks to be the length of the decrypted + * symlink target (or the no-key encoded symlink target, if the key is + * unavailable) rather than the length of the encrypted symlink target. This is + * necessary for st_size to match the symlink target that userspace actually + * sees. POSIX requires this, and some userspace programs depend on it. + * + * This requires reading the symlink target from disk if needed, setting up the + * inode's encryption key if possible, and then decrypting or encoding the + * symlink target. This makes lstat() more heavyweight than is normally the + * case. However, decrypted symlink targets will be cached in ->i_link, so + * usually the symlink won't have to be read and decrypted again later if/when + * it is actually followed, readlink() is called, or lstat() is called again. + * + * Return: 0 on success, -errno on failure + */ +int fscrypt_symlink_getattr(const struct path *path, struct kstat *stat) +{ + struct dentry *dentry = path->dentry; + struct inode *inode = d_inode(dentry); + const char *link; + DEFINE_DELAYED_CALL(done); + + /* + * To get the symlink target that userspace will see (whether it's the + * decrypted target or the no-key encoded target), we can just get it in + * the same way the VFS does during path resolution and readlink(). + */ + link = READ_ONCE(inode->i_link); + if (!link) { + link = inode->i_op->get_link(dentry, inode, &done); + if (IS_ERR(link)) + return PTR_ERR(link); + } + stat->size = strlen(link); + do_delayed_call(&done); + return 0; +} +EXPORT_SYMBOL_GPL(fscrypt_symlink_getattr); diff --git a/include/linux/fscrypt_notsupp.h b/include/linux/fscrypt_notsupp.h index 93304cfeb601..6e95c5a9b7fa 100644 --- a/include/linux/fscrypt_notsupp.h +++ b/include/linux/fscrypt_notsupp.h @@ -234,4 +234,10 @@ static inline const char *fscrypt_get_symlink(struct inode *inode, return ERR_PTR(-EOPNOTSUPP); } +static inline int fscrypt_symlink_getattr(const struct path *path, + struct kstat *stat) +{ + return -EOPNOTSUPP; +} + #endif /* _LINUX_FSCRYPT_NOTSUPP_H */ diff --git a/include/linux/fscrypt_supp.h b/include/linux/fscrypt_supp.h index 0409c14ae1de..f4cb4871a987 100644 --- a/include/linux/fscrypt_supp.h +++ b/include/linux/fscrypt_supp.h @@ -231,5 +231,6 @@ extern int __fscrypt_encrypt_symlink(struct inode *inode, const char *target, extern const char *fscrypt_get_symlink(struct inode *inode, const void *caddr, unsigned int max_size, struct delayed_call *done); +int fscrypt_symlink_getattr(const struct path *path, struct kstat *stat); #endif /* _LINUX_FSCRYPT_SUPP_H */ From patchwork Wed Sep 8 21:50:31 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 508319 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=ham 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 DF9B0C433FE for ; Wed, 8 Sep 2021 21:51:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CC34B61166 for ; Wed, 8 Sep 2021 21:51:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235642AbhIHVwj (ORCPT ); Wed, 8 Sep 2021 17:52:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:38288 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235602AbhIHVwh (ORCPT ); Wed, 8 Sep 2021 17:52:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 0B7E8610F8; Wed, 8 Sep 2021 21:51:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631137889; bh=KoVck986relZorHv7Og0MrrnvSEGPQxM/Ce82S4543I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=djxv3m0xGbBVx+UNIvmpHx8cZckH7eE8lOVxji2c4kw6syS4aTOebWeaYfIU2OlZn 5mkJiQwQN8zUcAHRbz+vHGtcRPj+b80614KfoJND4jKGVBCU4d3AvgDQegdEbV9AGf Yvuo/EFdvS1er0WGlHd2sc/7RtLAGNA/ZsivoIl62PXpNoTwuY9zCYS7JiHE2QroN9 RFIgFr7Er89OvNZwiPXjvCToXflBgNUIHgw6RTrPAqHPNweItKIee4IZEIGZc9zhBD g7OLKhrryDH847WLVqTS74OFy4hD0wca7jtZUQ+dRUeTmy+aM3SwpvvAYPdXuj4Fyi CHYRZsoHOcKAg== From: Eric Biggers To: stable@vger.kernel.org Cc: linux-fscrypt@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org Subject: [PATCH 2/4] ext4: report correct st_size for encrypted symlinks Date: Wed, 8 Sep 2021 14:50:31 -0700 Message-Id: <20210908215033.1122580-3-ebiggers@kernel.org> X-Mailer: git-send-email 2.33.0.153.gba50c8fa24-goog In-Reply-To: <20210908215033.1122580-1-ebiggers@kernel.org> References: <20210908215033.1122580-1-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 dd05af983092..a9457fed351e 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, }; From patchwork Wed Sep 8 21:50:32 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 508756 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 44CA0C4332F for ; Wed, 8 Sep 2021 21:51:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D3B761166 for ; Wed, 8 Sep 2021 21:51:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235595AbhIHVwj (ORCPT ); Wed, 8 Sep 2021 17:52:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:38294 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235491AbhIHVwh (ORCPT ); Wed, 8 Sep 2021 17:52:37 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5B4BA60FDA; Wed, 8 Sep 2021 21:51:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631137889; bh=i6jyH8PvgB9yhUYtCQiIMlEe2F7QGBiOJVd7oI0isaQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=uc0ABPV3twDuxLbMd8GxOBFitN/d4dzY/uDlYPFrSwJ2ssdr1If877Acir+VjZZ8n Nt/1rGsencho7jBMorqXtpxbbAGOew+veyR+teonjCszMDWx75NRw2lv/M/1JDvZgE p6ecHZl1/g/3/8zg5mkWJqIhBqONxZnc+NctmDqqVS45hJ+/JP9bsKIhSTIVU4hLJT mC6a5VpUhXm37nyOBu54PPLjy8QaT9GOey4LjQfuAp8Nz0dM8f7Qgw9gHni6eqO2Hr br4oThTq/jK3hdSY3kuxtu/Qxx8lyhEc545uStdAaEsUArmfAqD5pOq6M2Ok1P+Rq6 Y/EuKsKzzo1Ug== From: Eric Biggers To: stable@vger.kernel.org Cc: linux-fscrypt@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org Subject: [PATCH 3/4] f2fs: report correct st_size for encrypted symlinks Date: Wed, 8 Sep 2021 14:50:32 -0700 Message-Id: <20210908215033.1122580-4-ebiggers@kernel.org> X-Mailer: git-send-email 2.33.0.153.gba50c8fa24-goog In-Reply-To: <20210908215033.1122580-1-ebiggers@kernel.org> References: <20210908215033.1122580-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Biggers commit 461b43a8f92e68e96c4424b31e15f2b35f1bbfa9 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 f2fs_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: cbaf042a3cc6 ("f2fs crypto: add symlink encryption") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210702065350.209646-4-ebiggers@kernel.org Signed-off-by: Eric Biggers --- fs/f2fs/namei.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c index e20a0f9e6845..edc80855974a 100644 --- a/fs/f2fs/namei.c +++ b/fs/f2fs/namei.c @@ -1219,9 +1219,18 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry, return target; } +static int f2fs_encrypted_symlink_getattr(const struct path *path, + struct kstat *stat, u32 request_mask, + unsigned int query_flags) +{ + f2fs_getattr(path, stat, request_mask, query_flags); + + return fscrypt_symlink_getattr(path, stat); +} + const struct inode_operations f2fs_encrypted_symlink_inode_operations = { .get_link = f2fs_encrypted_get_link, - .getattr = f2fs_getattr, + .getattr = f2fs_encrypted_symlink_getattr, .setattr = f2fs_setattr, #ifdef CONFIG_F2FS_FS_XATTR .listxattr = f2fs_listxattr, From patchwork Wed Sep 8 21:50:33 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Biggers X-Patchwork-Id: 508318 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=ham 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 B7714C4321E for ; Wed, 8 Sep 2021 21:51:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A2FA361175 for ; Wed, 8 Sep 2021 21:51:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235723AbhIHVwl (ORCPT ); Wed, 8 Sep 2021 17:52:41 -0400 Received: from mail.kernel.org ([198.145.29.99]:38310 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235135AbhIHVwi (ORCPT ); Wed, 8 Sep 2021 17:52:38 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id AE0216115B; Wed, 8 Sep 2021 21:51:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1631137889; bh=Q7/Auj+gxb7Tq2h7AKECQp7f+V7wXd8uIeRwsSwC2uI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g6B3xPzWzmSOWbVujz05WcWiMqbJmrvjf663bftxNBe3SpFvKrqnf9HjmQt02WCYM SWydEF5fnJe2PDJt02TSsWwnOJNVN0DQIA8QyX31MW4y4bh6/xnq2+ec4fqkHIuubd SvzFgbwlnsZrqqazTbtxtlvrW9iAUFJ0MBEqmS/KMjUsF4ZUwPLf58CtQO2n3YuINH mUhMtIpAHEDSWvdU8iX5EZZMCqDZHUUQ0lA4wUD7b1eC2QFKcNXTByJg0iLHO3eXl9 YqTesOY0LwkjQtsa9SStbmzHvBr/PfEGeGubbTW0QRwltraAP+uT2feQHOEReo6aol SXsE9sw2hR4Kw== From: Eric Biggers To: stable@vger.kernel.org Cc: linux-fscrypt@vger.kernel.org, linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, linux-mtd@lists.infradead.org Subject: [PATCH 4/4] ubifs: report correct st_size for encrypted symlinks Date: Wed, 8 Sep 2021 14:50:33 -0700 Message-Id: <20210908215033.1122580-5-ebiggers@kernel.org> X-Mailer: git-send-email 2.33.0.153.gba50c8fa24-goog In-Reply-To: <20210908215033.1122580-1-ebiggers@kernel.org> References: <20210908215033.1122580-1-ebiggers@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Eric Biggers commit 064c734986011390b4d111f1a99372b7f26c3850 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 ubifs_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: ca7f85be8d6c ("ubifs: Add support for encrypted symlinks") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20210702065350.209646-5-ebiggers@kernel.org Signed-off-by: Eric Biggers --- fs/ubifs/file.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c index d7d2fdda4bbd..3dbb5ac630e4 100644 --- a/fs/ubifs/file.c +++ b/fs/ubifs/file.c @@ -1642,6 +1642,16 @@ static const char *ubifs_get_link(struct dentry *dentry, return fscrypt_get_symlink(inode, ui->data, ui->data_len, done); } +static int ubifs_symlink_getattr(const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int query_flags) +{ + ubifs_getattr(path, stat, request_mask, query_flags); + + if (IS_ENCRYPTED(d_inode(path->dentry))) + return fscrypt_symlink_getattr(path, stat); + return 0; +} + const struct address_space_operations ubifs_file_address_operations = { .readpage = ubifs_readpage, .writepage = ubifs_writepage, @@ -1669,7 +1679,7 @@ const struct inode_operations ubifs_file_inode_operations = { const struct inode_operations ubifs_symlink_inode_operations = { .get_link = ubifs_get_link, .setattr = ubifs_setattr, - .getattr = ubifs_getattr, + .getattr = ubifs_symlink_getattr, #ifdef CONFIG_UBIFS_FS_XATTR .listxattr = ubifs_listxattr, #endif