Received-SPF: pass (google.com: domain of linux-kernel+bounces-56233-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:45d1:ec00::1 as permitted sender) client-ip=2604:1380:45d1:ec00::1;
From: Luis Henriques <lhenriques@suse.de>
To: Eric Biggers <ebiggers@kernel.org>
Cc: "Theodore Y. Ts'o" <tytso@mit.edu>,  Jaegeuk Kim <jaegeuk@kernel.org>,
  David Howells <dhowells@redhat.com>,  Jarkko Sakkinen
 <jarkko@kernel.org>,  linux-fscrypt@vger.kernel.org,
  linux-kernel@vger.kernel.org
Subject: Re: [PATCH] fscrypt: clear keyring before calling key_put()
In-Reply-To: <20240207005731.GB35324@sol.localdomain> (Eric Biggers's message
	of "Tue, 6 Feb 2024 16:57:31 -0800")
References: <20240206101619.8083-1-lhenriques@suse.de>
	<20240207005731.GB35324@sol.localdomain>
Date: Wed, 07 Feb 2024 09:37:06 +0000
Message-ID: <87ttmkaa4d.fsf@suse.de>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable

Eric Biggers <ebiggers@kernel.org> writes:

> On Tue, Feb 06, 2024 at 10:16:19AM +0000, Luis Henriques wrote:
>> Now that the key quotas are handled immediately on key_put() instead of
>> being postponed to the key management garbage collection worker, a call =
to
>> keyring_clear() is all that is required in fscrypt_put_master_key() so t=
hat
>> the keyring clean-up is also done synchronously.  This patch should fix =
the
>> fstest generic/581 flakiness.
>>=20
>> Signed-off-by: Luis Henriques <lhenriques@suse.de>
>> ---
>> Hi!
>>=20
>> I know that patch "keys: update key quotas in key_put()" isn't yet merged
>> but since David and Jarkko seem to be OK with it, it doesn't hurt to send
>> this follow-up patch immediately.
>>=20
>> Cheers,
>> --=20
>> Luis
>>=20
>>  fs/crypto/keyring.c | 7 +++++--
>>  1 file changed, 5 insertions(+), 2 deletions(-)
>>=20
>> diff --git a/fs/crypto/keyring.c b/fs/crypto/keyring.c
>> index 0edf0b58daa7..dfdaae16b83a 100644
>> --- a/fs/crypto/keyring.c
>> +++ b/fs/crypto/keyring.c
>> @@ -74,8 +74,11 @@ void fscrypt_put_master_key(struct fscrypt_master_key=
 *mk)
>>  	 * that concurrent keyring lookups can no longer find it.
>>  	 */
>>  	WARN_ON_ONCE(refcount_read(&mk->mk_active_refs) !=3D 0);
>> -	key_put(mk->mk_users);
>> -	mk->mk_users =3D NULL;
>> +	if (mk->mk_users) {
>> +		keyring_clear(mk->mk_users);
>> +		key_put(mk->mk_users);
>> +		mk->mk_users =3D NULL;
>> +	}
>>  	call_rcu(&mk->mk_rcu_head, fscrypt_free_master_key);
>
> Applied, thanks.  I added a comment above the call to keyring_clear() to =
explain
> why it's there:
>
>         /* Clear the keyring so the quota gets released right away. */

Awesome, makes sense.  Thanks a lot, Eric!

Cheers,
--=20
Lu=C3=ADs