Re: [PATCH 1/1] digsig: Fix memory leakage in digsig_verify_rsa()

From: Kasatkin, Dmitry
Date: Thu Jan 31 2013 - 02:20:30 EST


On Thu, Jan 31, 2013 at 3:02 AM, James Morris <jmorris@xxxxxxxxx> wrote:
> What's the practical impact of this? Could an attacker kill the machine?
>
>

It might be possible slowly to eat the whole memory if there were too
many memory verifications.
This is a bug and the patch will be applied to stable.
Should go to mainline as well.

I suggest to apply it and also couple of other patches I sent yesterday.

thanks.

- Dmitry

> On Wed, 30 Jan 2013, Kasatkin, Dmitry wrote:
>
>> On Fri, Jan 25, 2013 at 4:54 PM, Dmitry Kasatkin
>> <dmitry.kasatkin@xxxxxxxxx> wrote:
>> > From: YOSHIFUJI Hideaki <yoshfuji@xxxxxxxxxxxxxx>
>> >
>> > digsig_verify_rsa() does not free kmalloc'ed buffer returned by
>> > mpi_get_buffer().
>> >
>> > Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@xxxxxxxxxxxxxx>
>> > Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@xxxxxxxxx>
>> > Cc: stable@xxxxxxxxxxxxxxx
>> > ---
>> > lib/digsig.c | 2 ++
>> > 1 file changed, 2 insertions(+)
>> >
>> > diff --git a/lib/digsig.c b/lib/digsig.c
>> > index 8c0e629..dc2be7e 100644
>> > --- a/lib/digsig.c
>> > +++ b/lib/digsig.c
>> > @@ -162,6 +162,8 @@ static int digsig_verify_rsa(struct key *key,
>> > memset(out1, 0, head);
>> > memcpy(out1 + head, p, l);
>> >
>> > + kfree(p);
>> > +
>> > err = pkcs_1_v1_5_decode_emsa(out1, len, mblen, out2, &len);
>> > if (err)
>> > goto err;
>> > --
>> > 1.7.10.4
>> >
>>
>> James, can you please apply this patch.
>>
>> - Dmitry
>>
>
> --
> James Morris
> <jmorris@xxxxxxxxx>
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