From: Richard Weinberger Subject: Re: [PATCH] fscrypto: move ioctl processing more fully into common code Date: Tue, 18 Oct 2016 14:22:07 +0200 Message-ID: References: <1476723246-47420-1-git-send-email-ebiggers@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: linux-fsdevel , linux-ext4@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, "Theodore Ts'o" , jaegeuk@kernel.org, David Gstir To: Eric Biggers Return-path: In-Reply-To: <1476723246-47420-1-git-send-email-ebiggers@google.com> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Eric, On Mon, Oct 17, 2016 at 6:54 PM, Eric Biggers wrote: > Multiple bugs were recently fixed in the "set encryption policy" ioctl. > To make it clear that fscrypt_process_policy() and fscrypt_get_policy() > implement ioctls and therefore their implementations must take standard > security and correctness precautions, rename them to > fscrypt_ioctl_set_policy() and fscrypt_ioctl_get_policy(). Make the > latter take in a struct file * to make it consistent with the former. > > In addition, make the common functions do the copies to and from > userspace rather than duplicating this code within each filesystem, and > memset the policy to 0 to make it clear there is no stack leak. > > Signed-off-by: Eric Biggers > --- > fs/crypto/policy.c | 36 +++++++++++++++++++++++------------- > fs/ext4/ext4.h | 4 ++-- > fs/ext4/ioctl.c | 34 +++++----------------------------- > fs/f2fs/f2fs.h | 4 ++-- > fs/f2fs/file.c | 19 ++----------------- > include/linux/fscrypto.h | 12 ++++++------ > 6 files changed, 40 insertions(+), 69 deletions(-) Hmm, are you sure the change is worth it? The patch basically moves a copy_from/to_user() from ext4/f2fs into fscrypto. -- Thanks, //richard