From: Waiman Long <longman@redhat.com>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: Eric Biggers <ebiggers@kernel.org>,
David Howells <dhowells@redhat.com>,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>,
linux-mm@kvack.org, keyrings@vger.kernel.org,
linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Joe Perches <joe@perches.com>,
Matthew Wilcox <willy@infradead.org>,
David Rientjes <rientjes@google.com>
Subject: Re: [PATCH v3] mm: Add kvfree_sensitive() for freeing sensitive data objects
Date: Sun, 3 May 2020 22:57:23 -0400 [thread overview]
Message-ID: <82fbc32f-3f9e-b876-b998-7714e8597988@redhat.com> (raw)
In-Reply-To: <20200501232224.GC915@sol.localdomain>
On 5/1/20 7:22 PM, Eric Biggers wrote:
> On Tue, Apr 07, 2020 at 04:03:18PM -0400, Waiman Long wrote:
>> For kvmalloc'ed data object that contains sensitive information like
>> cryptographic key, we need to make sure that the buffer is always
>> cleared before freeing it. Using memset() alone for buffer clearing may
>> not provide certainty as the compiler may compile it away. To be sure,
>> the special memzero_explicit() has to be used.
>>
>> This patch introduces a new kvfree_sensitive() for freeing those
>> sensitive data objects allocated by kvmalloc(). The relevnat places
>> where kvfree_sensitive() can be used are modified to use it.
>>
>> Fixes: 4f0882491a14 ("KEYS: Avoid false positive ENOMEM error on key read")
>> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
>> Signed-off-by: Waiman Long <longman@redhat.com>
> Looks good, feel free to add:
>
> Reviewed-by: Eric Biggers <ebiggers@google.com>
>
> (I don't really buy the argument that the compiler could compile away memset()
> before kvfree(). But I agree with using memzero_explicit() anyway to make the
> intent explicit.)
>
> I don't see this patch in linux-next yet. Who is planning to take this patch?
> Presumably David through the keyrings tree, or Andrew through mm?
>
> - Eric
>
Andrew, would you mind taking this patch into the mm-tree?
Thanks,
Longman
next prev parent reply other threads:[~2020-05-04 2:57 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-07 20:03 [PATCH v3] mm: Add kvfree_sensitive() for freeing sensitive data objects Waiman Long
2020-04-07 20:09 ` Linus Torvalds
2020-04-07 20:19 ` David Howells
2020-04-07 20:24 ` Waiman Long
2020-04-07 20:21 ` David Howells
2020-05-05 20:35 ` Andrew Morton
2020-05-06 1:29 ` Waiman Long
2020-04-07 20:31 ` Joe Perches
2020-04-07 20:45 ` Waiman Long
2020-04-07 21:01 ` Linus Torvalds
2020-04-07 21:24 ` Uladzislau Rezki
2020-04-07 21:30 ` Linus Torvalds
2020-04-07 22:12 ` Matthew Wilcox
2020-04-08 0:35 ` Joe Perches
2020-04-08 13:38 ` Jarkko Sakkinen
2020-05-01 23:22 ` Eric Biggers
2020-05-04 2:57 ` Waiman Long [this message]
2020-05-14 11:00 ` Balbir Singh
2020-05-14 12:00 ` Matthew Wilcox
2020-05-14 12:08 ` Joe Perches
2020-05-17 0:27 ` Balbir Singh
2020-05-17 0:44 ` Matthew Wilcox
2020-05-18 2:39 ` Waiman Long
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