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>,
keyrings@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-integrity@vger.kernel.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 v3 2/3] KEYS: Avoid false positive ENOMEM error on key read
Date: Tue, 17 Mar 2020 14:36:50 -0400 [thread overview]
Message-ID: <98feb3ff-835a-e4cf-40a9-284d21e16993@redhat.com> (raw)
In-Reply-To: <20200315213245.GF224162@linux.intel.com>
On 3/15/20 5:32 PM, Jarkko Sakkinen wrote:
> On Fri, Mar 13, 2020 at 11:21:01AM -0400, Waiman Long wrote:
>> - * Read methods will just return the required length
>> - * without any copying if the provided length isn't big
>> - * enough.
>> + * We don't want an erronous -ENOMEM error due to an
>> + * arbitrary large user-supplied buflen. So if buflen
>> + * exceeds a threshold (1024 bytes in this case), we call
>> + * the read method twice. The first time to get the buffer
>> + * length and the second time to read out the key data.
>> + *
>> + * N.B. All the read methods will return the required
>> + * buffer length with a NULL input buffer or when
>> + * the input buffer length isn't large enough.
>> */
>> + if (buflen <= 0x400) {
> 1. The overwhelmingly long comment. Will be destined to rotten.
> 2. Magic number.
> 3. The cap must be updated both in comment and code, and not only
> that, but the numbers use a different base (dec and hex).
>
> /Jarkko
>
Thank for the comment. I will make the necessary change.
Cheers,
Longman
next prev parent reply other threads:[~2020-03-17 18:36 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-03-13 15:20 [PATCH v3 0/3] KEYS: Read keys to internal buffer & then copy to userspace Waiman Long
2020-03-13 15:21 ` [PATCH v3 1/3] KEYS: Don't write out to userspace while holding key semaphore Waiman Long
2020-03-15 19:21 ` Jarkko Sakkinen
2020-03-15 21:27 ` Jarkko Sakkinen
2020-03-16 11:22 ` David Howells
2020-03-16 13:53 ` Jarkko Sakkinen
2020-03-16 16:33 ` Waiman Long
2020-03-17 18:10 ` Waiman Long
2020-03-16 11:34 ` David Howells
2020-03-13 15:21 ` [PATCH v3 2/3] KEYS: Avoid false positive ENOMEM error on key read Waiman Long
2020-03-15 21:32 ` Jarkko Sakkinen
2020-03-17 18:36 ` Waiman Long [this message]
2020-03-13 15:21 ` [PATCH v3 3/3] KEYS: Use kvmalloc() to better handle large buffer allocation Waiman Long
2020-03-13 16:43 ` Eric Biggers
2020-03-13 17:49 ` Waiman Long
2020-03-15 21:52 ` Jarkko Sakkinen
2020-03-15 22:01 ` Waiman Long
2020-03-16 11:50 ` [PATCH v3 1/3] KEYS: Don't write out to userspace while holding key semaphore David Howells
2020-03-17 18:09 ` Waiman Long
2020-03-16 14:24 ` [PATCH v3 3/3] KEYS: Use kvmalloc() to better handle large buffer allocation David Howells
2020-03-16 15:21 ` Waiman Long
2020-03-16 22:19 ` Jarkko Sakkinen
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