Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753173AbbBYCyM (ORCPT ); Tue, 24 Feb 2015 21:54:12 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:43309 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753103AbbBYCyK (ORCPT ); Tue, 24 Feb 2015 21:54:10 -0500 From: Tyler Hicks To: ecryptfs@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Rocko , Colin Ian King Subject: [PATCH] eCryptfs: don't pass fs-specific ioctl commands through Date: Tue, 24 Feb 2015 20:53:26 -0600 Message-Id: <1424832806-10386-1-git-send-email-tyhicks@canonical.com> X-Mailer: git-send-email 2.1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2975 Lines: 92 eCryptfs can't be aware of what to expect when after passing an arbitrary ioctl command through to the lower filesystem. The ioctl command may trigger an action in the lower filesystem that is incompatible with eCryptfs. One specific example is when one attempts to use the Btrfs clone ioctl command when the source file is in the Btrfs filesystem that eCryptfs is mounted on top of and the destination fd is from a new file created in the eCryptfs mount. The ioctl syscall incorrectly returns success because the command is passed down to Btrfs which thinks that it was able to do the clone operation. However, the result is an empty eCryptfs file. This patch allows the trim, {g,s}etflags, and {g,s}etversion ioctl commands through and then copies up the inode metadata from the lower inode to the eCryptfs inode to catch any changes made to the lower inode's metadata. Those five ioctl commands are mostly common across all filesystems but the whitelist may need to be further pruned in the future. https://bugzilla.kernel.org/show_bug.cgi?id=93691 https://launchpad.net/bugs/1305335 Signed-off-by: Tyler Hicks Cc: Rocko Cc: Colin Ian King --- fs/ecryptfs/file.c | 34 ++++++++++++++++++++++++++++++---- 1 file changed, 30 insertions(+), 4 deletions(-) diff --git a/fs/ecryptfs/file.c b/fs/ecryptfs/file.c index b07731e..fd39bad 100644 --- a/fs/ecryptfs/file.c +++ b/fs/ecryptfs/file.c @@ -303,9 +303,22 @@ ecryptfs_unlocked_ioctl(struct file *file, unsigned int cmd, unsigned long arg) struct file *lower_file = ecryptfs_file_to_lower(file); long rc = -ENOTTY; - if (lower_file->f_op->unlocked_ioctl) + if (!lower_file->f_op->unlocked_ioctl) + return rc; + + switch (cmd) { + case FITRIM: + case FS_IOC_GETFLAGS: + case FS_IOC_SETFLAGS: + case FS_IOC_GETVERSION: + case FS_IOC_SETVERSION: rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg); - return rc; + fsstack_copy_attr_all(file_inode(file), file_inode(lower_file)); + + return rc; + default: + return rc; + } } #ifdef CONFIG_COMPAT @@ -315,9 +328,22 @@ ecryptfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg) struct file *lower_file = ecryptfs_file_to_lower(file); long rc = -ENOIOCTLCMD; - if (lower_file->f_op->compat_ioctl) + if (!lower_file->f_op->compat_ioctl) + return rc; + + switch (cmd) { + case FITRIM: + case FS_IOC32_GETFLAGS: + case FS_IOC32_SETFLAGS: + case FS_IOC32_GETVERSION: + case FS_IOC32_SETVERSION: rc = lower_file->f_op->compat_ioctl(lower_file, cmd, arg); - return rc; + fsstack_copy_attr_all(file_inode(file), file_inode(lower_file)); + + return rc; + default: + return rc; + } } #endif -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/