From: Eric Biggers <ebiggers@kernel.org>
To: "Theodore Y. Ts'o" <tytso@mit.edu>
Cc: Satya Tangirala <satyat@google.com>,
linux-api@vger.kernel.org,
linux-f2fs-devel@lists.sourceforge.net,
linux-fscrypt@vger.kernel.org, keyrings@vger.kernel.org,
linux-mtd@lists.infradead.org, linux-crypto@vger.kernel.org,
linux-fsdevel@vger.kernel.org, Jaegeuk Kim <jaegeuk@kernel.org>,
linux-ext4@vger.kernel.org, Paul Crowley <paulcrowley@google.com>
Subject: Re: [PATCH v8 10/20] fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY ioctl
Date: Wed, 14 Aug 2019 15:35:43 -0700 [thread overview]
Message-ID: <20190814223542.GE101319@gmail.com> (raw)
In-Reply-To: <20190813000644.GH28705@mit.edu>
On Mon, Aug 12, 2019 at 08:06:44PM -0400, Theodore Y. Ts'o wrote:
> > + /* Some inodes still reference this key; try to evict them. */
> > + if (try_to_lock_encrypted_files(sb, mk) != 0)
> > + status_flags |=
> > + FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY;
> > + }
>
> try_to_lock_encrypted_files() can return other errors besides -EBUSY;
> in particular sync_filesystem() can return other errors, such as -EIO
> or -EFSCORUPTED. In that case, I think we're better off returning the
> relevant status code back to the user. We will have already wiped the
> master key, but this situation will only happen in exceptional
> conditions (e.g., user has ejected the sdcard, etc.), so it's not
> worth it to try to undo the master key wipe to try to restore things
> to the pre-ioctl execution state.
>
> So I think we should capture the return code from
> try_to_lock_encrypted_files, and if it is EBUSY, we can set FILES_BUSY
> flag and return success. Otherwise, we should return the error.
>
> If you agree, please fix that up and then feel free to add:
>
> Reviewed-by: Theodore Ts'o <tytso@mit.edu>
>
> - Ted
Yes, that makes sense. I've made the following change to this patch:
diff --git a/fs/crypto/keyring.c b/fs/crypto/keyring.c
index 9901593051424b..c3423f0edc7014 100644
--- a/fs/crypto/keyring.c
+++ b/fs/crypto/keyring.c
@@ -479,6 +479,7 @@ int fscrypt_ioctl_remove_key(struct file *filp, void __user *_uarg)
struct key *key;
struct fscrypt_master_key *mk;
u32 status_flags = 0;
+ int err;
bool dead;
if (copy_from_user(&arg, uarg, sizeof(arg)))
@@ -514,11 +515,15 @@ int fscrypt_ioctl_remove_key(struct file *filp, void __user *_uarg)
* key object is free to be removed from the keyring.
*/
key_invalidate(key);
+ err = 0;
} else {
/* Some inodes still reference this key; try to evict them. */
- if (try_to_lock_encrypted_files(sb, mk) != 0)
+ err = try_to_lock_encrypted_files(sb, mk);
+ if (err == -EBUSY) {
status_flags |=
FSCRYPT_KEY_REMOVAL_STATUS_FLAG_FILES_BUSY;
+ err = 0;
+ }
}
/*
* We return 0 if we successfully did something: wiped the secret, or
@@ -527,7 +532,9 @@ int fscrypt_ioctl_remove_key(struct file *filp, void __user *_uarg)
* including all files locked.
*/
key_put(key);
- return put_user(status_flags, &uarg->removal_status_flags);
+ if (err == 0)
+ err = put_user(status_flags, &uarg->removal_status_flags);
+ return err;
}
EXPORT_SYMBOL_GPL(fscrypt_ioctl_remove_key);
______________________________________________________
Linux MTD discussion mailing list
http://lists.infradead.org/mailman/listinfo/linux-mtd/
next prev parent reply other threads:[~2019-08-14 22:36 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-05 16:25 [PATCH v8 00/20] fscrypt: key management improvements Eric Biggers
2019-08-05 16:25 ` [PATCH v8 01/20] fs, fscrypt: move uapi definitions to new header <linux/fscrypt.h> Eric Biggers
2019-08-05 16:25 ` [PATCH v8 02/20] fscrypt: use FSCRYPT_ prefix for uapi constants Eric Biggers
2019-08-05 16:25 ` [PATCH v8 03/20] fscrypt: use FSCRYPT_* definitions, not FS_* Eric Biggers
2019-08-05 16:25 ` [PATCH v8 04/20] fscrypt: add ->ci_inode to fscrypt_info Eric Biggers
2019-08-05 16:25 ` [PATCH v8 05/20] fscrypt: rename fscrypt_master_key to fscrypt_direct_key Eric Biggers
2019-08-12 22:20 ` Theodore Y. Ts'o
2019-08-05 16:25 ` [PATCH v8 06/20] fscrypt: refactor key setup code in preparation for v2 policies Eric Biggers
2019-08-12 22:38 ` Theodore Y. Ts'o
2019-08-05 16:25 ` [PATCH v8 07/20] fscrypt: move v1 policy key setup to keysetup_v1.c Eric Biggers
2019-08-12 22:53 ` Theodore Y. Ts'o
2019-08-05 16:25 ` [PATCH v8 08/20] fscrypt: rename keyinfo.c to keysetup.c Eric Biggers
2019-08-12 22:53 ` Theodore Y. Ts'o
2019-08-05 16:25 ` [PATCH v8 09/20] fscrypt: add FS_IOC_ADD_ENCRYPTION_KEY ioctl Eric Biggers
2019-08-05 16:25 ` [PATCH v8 10/20] fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY ioctl Eric Biggers
2019-08-13 0:06 ` Theodore Y. Ts'o
2019-08-14 22:35 ` Eric Biggers [this message]
2019-08-05 16:25 ` [PATCH v8 11/20] fscrypt: add FS_IOC_GET_ENCRYPTION_KEY_STATUS ioctl Eric Biggers
2019-08-05 16:25 ` [PATCH v8 12/20] fscrypt: add an HKDF-SHA512 implementation Eric Biggers
2019-08-06 20:43 ` Paul Crowley
2019-08-05 16:25 ` [PATCH v8 13/20] fscrypt: v2 encryption policy support Eric Biggers
2019-08-06 20:44 ` Paul Crowley
2019-08-13 0:39 ` Theodore Y. Ts'o
2019-08-05 16:25 ` [PATCH v8 14/20] fscrypt: allow unprivileged users to add/remove keys for v2 policies Eric Biggers
2019-08-13 0:14 ` Theodore Y. Ts'o
2019-08-05 16:25 ` [PATCH v8 15/20] fscrypt: add FS_IOC_REMOVE_ENCRYPTION_KEY_ALL_USERS ioctl Eric Biggers
2019-08-13 0:15 ` Theodore Y. Ts'o
2019-08-05 16:25 ` [PATCH v8 16/20] fscrypt: require that key be added when setting a v2 encryption policy Eric Biggers
2019-08-05 16:25 ` [PATCH v8 17/20] ext4: wire up new fscrypt ioctls Eric Biggers
2019-08-05 16:25 ` [PATCH v8 18/20] f2fs: " Eric Biggers
2019-08-05 16:25 ` [PATCH v8 19/20] ubifs: " Eric Biggers
2019-08-05 16:25 ` [PATCH v8 20/20] fscrypt: document the new ioctls and policy version Eric Biggers
2019-08-13 0:49 ` Theodore Y. Ts'o
2019-08-14 22:37 ` [PATCH v8 00/20] fscrypt: key management improvements Eric Biggers
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190814223542.GE101319@gmail.com \
--to=ebiggers@kernel.org \
--cc=jaegeuk@kernel.org \
--cc=keyrings@vger.kernel.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-crypto@vger.kernel.org \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-f2fs-devel@lists.sourceforge.net \
--cc=linux-fscrypt@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-mtd@lists.infradead.org \
--cc=paulcrowley@google.com \
--cc=satyat@google.com \
--cc=tytso@mit.edu \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).