From: Waiman Long <longman@redhat.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: David Howells <dhowells@redhat.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
Mimi Zohar <zohar@linux.ibm.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
keyrings@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-integrity@vger.kernel.org, netdev@vger.kernel.org,
linux-afs@lists.infradead.org, Sumit Garg <sumit.garg@linaro.org>,
Jerry Snitselaar <jsnitsel@redhat.com>,
Roberto Sassu <roberto.sassu@huawei.com>,
Eric Biggers <ebiggers@google.com>,
Chris von Recklinghausen <crecklin@redhat.com>
Subject: Re: [PATCH v5 2/2] KEYS: Avoid false positive ENOMEM error on key read
Date: Fri, 20 Mar 2020 00:07:55 +0000 [thread overview]
Message-ID: <f22757ad-4d6f-ffd2-eed5-6b9bd1621b10@redhat.com> (raw)
In-Reply-To: <20200319194650.GA24804@linux.intel.com>
On 3/19/20 3:46 PM, Jarkko Sakkinen wrote:
> On Wed, Mar 18, 2020 at 06:14:57PM -0400, Waiman Long wrote:
>> + * It is possible, though unlikely, that the key
>> + * changes in between the up_read->down_read period.
>> + * If the key becomes longer, we will have to
>> + * allocate a larger buffer and redo the key read
>> + * again.
>> + */
>> + if (!tmpbuf || unlikely(ret > tmpbuflen)) {
> Shouldn't you check that tmpbuflen stays below buflen (why else
> you had made copy of buflen otherwise)?
The check above this thunk:
if ((ret > 0) && (ret <= buflen)) {
will make sure that ret will not be larger than buflen. So tmpbuflen
will never be bigger than buflen.
Cheers,
Longman
WARNING: multiple messages have this Message-ID (diff)
From: Waiman Long <longman@redhat.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc: David Howells <dhowells@redhat.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
Mimi Zohar <zohar@linux.ibm.com>,
"David S. Miller" <davem@davemloft.net>,
Jakub Kicinski <kuba@kernel.org>,
keyrings@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-integrity@vger.kernel.org, netdev@vger.kernel.org,
linux-afs@lists.infradead.org, Sumit Garg <sumit.garg@linaro.org>,
Jerry Snitselaar <jsnitsel@redhat.com>,
Roberto Sassu <roberto.sassu@huawei.com>,
Eric Biggers <ebiggers@google.com>,
Chris von Recklinghausen <crecklin@redhat.com>
Subject: Re: [PATCH v5 2/2] KEYS: Avoid false positive ENOMEM error on key read
Date: Thu, 19 Mar 2020 20:07:55 -0400 [thread overview]
Message-ID: <f22757ad-4d6f-ffd2-eed5-6b9bd1621b10@redhat.com> (raw)
In-Reply-To: <20200319194650.GA24804@linux.intel.com>
On 3/19/20 3:46 PM, Jarkko Sakkinen wrote:
> On Wed, Mar 18, 2020 at 06:14:57PM -0400, Waiman Long wrote:
>> + * It is possible, though unlikely, that the key
>> + * changes in between the up_read->down_read period.
>> + * If the key becomes longer, we will have to
>> + * allocate a larger buffer and redo the key read
>> + * again.
>> + */
>> + if (!tmpbuf || unlikely(ret > tmpbuflen)) {
> Shouldn't you check that tmpbuflen stays below buflen (why else
> you had made copy of buflen otherwise)?
The check above this thunk:
if ((ret > 0) && (ret <= buflen)) {
will make sure that ret will not be larger than buflen. So tmpbuflen
will never be bigger than buflen.
Cheers,
Longman
next prev parent reply other threads:[~2020-03-20 0:07 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-18 22:14 [PATCH v5 0/2] KEYS: Read keys to internal buffer & then copy to userspace Waiman Long
2020-03-18 22:14 ` Waiman Long
2020-03-18 22:14 ` [PATCH v5 1/2] KEYS: Don't write out to userspace while holding key semaphore Waiman Long
2020-03-18 22:14 ` Waiman Long
2020-03-18 22:14 ` [PATCH v5 2/2] KEYS: Avoid false positive ENOMEM error on key read Waiman Long
2020-03-18 22:14 ` Waiman Long
2020-03-19 19:46 ` Jarkko Sakkinen
2020-03-19 19:46 ` Jarkko Sakkinen
2020-03-20 0:07 ` Waiman Long [this message]
2020-03-20 0:07 ` Waiman Long
2020-03-20 2:07 ` Jarkko Sakkinen
2020-03-20 2:07 ` Jarkko Sakkinen
2020-03-20 13:27 ` Waiman Long
2020-03-20 13:27 ` Waiman Long
2020-03-20 14:35 ` Jarkko Sakkinen
2020-03-20 14:35 ` Jarkko Sakkinen
2020-03-20 15:09 ` Waiman Long
2020-03-20 15:09 ` Waiman Long
2020-03-20 23:55 ` David Howells
2020-03-21 0:58 ` Jarkko Sakkinen
2020-03-21 0:58 ` Jarkko Sakkinen
2020-03-20 8:20 ` [PATCH v5 1/2] KEYS: Don't write out to userspace while holding key semaphore David Howells
2020-03-20 13:56 ` Waiman Long
2020-03-20 13:56 ` Waiman Long
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=f22757ad-4d6f-ffd2-eed5-6b9bd1621b10@redhat.com \
--to=longman@redhat.com \
--cc=crecklin@redhat.com \
--cc=davem@davemloft.net \
--cc=dhowells@redhat.com \
--cc=ebiggers@google.com \
--cc=jarkko.sakkinen@linux.intel.com \
--cc=jmorris@namei.org \
--cc=jsnitsel@redhat.com \
--cc=keyrings@vger.kernel.org \
--cc=kuba@kernel.org \
--cc=linux-afs@lists.infradead.org \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-security-module@vger.kernel.org \
--cc=netdev@vger.kernel.org \
--cc=roberto.sassu@huawei.com \
--cc=serge@hallyn.com \
--cc=sumit.garg@linaro.org \
--cc=zohar@linux.ibm.com \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.