From: Waiman Long <longman@redhat.com>
To: Joe Perches <joe@perches.com>,
Andrew Morton <akpm@linux-foundation.org>,
David Howells <dhowells@redhat.com>,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
James Morris <jmorris@namei.org>,
"Serge E. Hallyn" <serge@hallyn.com>
Cc: linux-mm@kvack.org, keyrings@vger.kernel.org,
linux-kernel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
Matthew Wilcox <willy@infradead.org>,
David Rientjes <rientjes@google.com>
Subject: Re: [PATCH v2] mm: Add kvfree_sensitive() for freeing sensitive data objects
Date: Mon, 6 Apr 2020 22:16:04 -0400 [thread overview]
Message-ID: <1e4a6174-04be-6c05-fd6e-b43fefd317fc@redhat.com> (raw)
In-Reply-To: <c2c8adf48be7cb18bbdf0aef7d21e2defe3d2183.camel@perches.com>
On 4/6/20 3:38 PM, Joe Perches wrote:
> On Mon, 2020-04-06 at 14:58 -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.
> []
>> extern void kvfree(const void *addr);
>> +extern void kvfree_sensitive(const void *addr, size_t len);
> Question: why should this be const?
>
> 2.1.44 changed kfree(void *) to kfree(const void *) but
> I didn't find a particular reason why.
I am just following the function prototype used by kvfree(). Even
kzfree(const void *) use const. I can remove "const" if others agree.
Cheers,
Longman
next prev parent reply other threads:[~2020-04-07 2:16 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-06 18:58 Waiman Long
2020-04-06 19:38 ` Joe Perches
2020-04-07 2:16 ` Waiman Long [this message]
2020-04-07 6:41 ` Joe Perches
2020-04-07 20:16 ` Linus Torvalds
2020-04-07 20:26 ` Linus Torvalds
2020-04-07 21:14 ` David Howells
2020-04-07 21:22 ` Linus Torvalds
2020-04-07 22:24 ` Matthew Wilcox
2020-04-07 22:54 ` David Howells
2020-04-07 23:50 ` Linus Torvalds
2020-04-06 20:00 ` Matthew Wilcox
2020-04-07 20:07 ` Waiman Long
2020-04-07 20:01 Waiman Long
2020-04-07 20:02 ` Waiman Long
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