From: Dan Carpenter <dan.carpenter@oracle.com>
To: Frans Klaver <fransklaver@gmail.com>
Cc: Lauro Ramos Venancio <lauro.venancio@openbossa.org>,
Eric Lapuyade <eric.lapuyade@linux.intel.com>,
Aloisio Almeida Jr <aloisio.almeida@openbossa.org>,
Samuel Ortiz <sameo@linux.intel.com>,
"John W. Linville" <linville@tuxdriver.com>,
Jeff Kirsher <jeffrey.t.kirsher@intel.com>,
linux-wireless@vger.kernel.org, linux-nfc@ml01.01.org,
kernel-janitors@vger.kernel.org,
Kees Cook <keescook@chromium.org>
Subject: Re: [patch -RESEND] NFC: potential overflows in microread_target_discovered()
Date: Tue, 02 Sep 2014 08:54:36 +0000 [thread overview]
Message-ID: <20140902085436.GE6549@mwanda> (raw)
In-Reply-To: <CAH6sp9NXUtOpagcaKOTJUH4m=2YcdeVoKDU4AHSvzyr+qcsFTA@mail.gmail.com>
On Tue, Sep 02, 2014 at 09:02:36AM +0200, Frans Klaver wrote:
> > diff --git a/drivers/nfc/microread/microread.c b/drivers/nfc/microread/microread.c
> > index f868333271aa..963a4a5dc88e 100644
> > --- a/drivers/nfc/microread/microread.c
> > +++ b/drivers/nfc/microread/microread.c
> > @@ -501,9 +501,13 @@ static void microread_target_discovered(struct nfc_hci_dev *hdev, u8 gate,
> > targets->sens_res > > be16_to_cpu(*(u16 *)&skb->data[MICROREAD_EMCF_A_ATQA]);
> > targets->sel_res = skb->data[MICROREAD_EMCF_A_SAK];
> > - memcpy(targets->nfcid1, &skb->data[MICROREAD_EMCF_A_UID],
> > - skb->data[MICROREAD_EMCF_A_LEN]);
> > targets->nfcid1_len = skb->data[MICROREAD_EMCF_A_LEN];
> > + if (targets->nfcid1_len > sizeof(targets->nfcid1)) {
>
> You should probably compare against sizeof(*targets->nfcid1).
>
No. It's an array not a pointer.
You should make a small test program to test your ideas.
int main(void)
{
char buf[10];
printf("%d %d\n", sizeof(buf), sizeof(*buf));
return 0;
}
regards,
dan carpenter
WARNING: multiple messages have this Message-ID (diff)
From: Dan Carpenter <dan.carpenter@oracle.com>
To: Frans Klaver <fransklaver@gmail.com>
Cc: Lauro Ramos Venancio <lauro.venancio@openbossa.org>,
Eric Lapuyade <eric.lapuyade@linux.intel.com>,
Aloisio Almeida Jr <aloisio.almeida@openbossa.org>,
Samuel Ortiz <sameo@linux.intel.com>,
"John W. Linville" <linville@tuxdriver.com>,
Jeff Kirsher <jeffrey.t.kirsher@intel.com>,
linux-wireless@vger.kernel.org, linux-nfc@ml01.01.org,
kernel-janitors@vger.kernel.org,
Kees Cook <keescook@chromium.org>
Subject: Re: [patch -RESEND] NFC: potential overflows in microread_target_discovered()
Date: Tue, 2 Sep 2014 11:54:36 +0300 [thread overview]
Message-ID: <20140902085436.GE6549@mwanda> (raw)
In-Reply-To: <CAH6sp9NXUtOpagcaKOTJUH4m=2YcdeVoKDU4AHSvzyr+qcsFTA@mail.gmail.com>
On Tue, Sep 02, 2014 at 09:02:36AM +0200, Frans Klaver wrote:
> > diff --git a/drivers/nfc/microread/microread.c b/drivers/nfc/microread/microread.c
> > index f868333271aa..963a4a5dc88e 100644
> > --- a/drivers/nfc/microread/microread.c
> > +++ b/drivers/nfc/microread/microread.c
> > @@ -501,9 +501,13 @@ static void microread_target_discovered(struct nfc_hci_dev *hdev, u8 gate,
> > targets->sens_res =
> > be16_to_cpu(*(u16 *)&skb->data[MICROREAD_EMCF_A_ATQA]);
> > targets->sel_res = skb->data[MICROREAD_EMCF_A_SAK];
> > - memcpy(targets->nfcid1, &skb->data[MICROREAD_EMCF_A_UID],
> > - skb->data[MICROREAD_EMCF_A_LEN]);
> > targets->nfcid1_len = skb->data[MICROREAD_EMCF_A_LEN];
> > + if (targets->nfcid1_len > sizeof(targets->nfcid1)) {
>
> You should probably compare against sizeof(*targets->nfcid1).
>
No. It's an array not a pointer.
You should make a small test program to test your ideas.
int main(void)
{
char buf[10];
printf("%d %d\n", sizeof(buf), sizeof(*buf));
return 0;
}
regards,
dan carpenter
next prev parent reply other threads:[~2014-09-02 8:54 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-01 17:27 [patch -RESEND] NFC: potential overflows in microread_target_discovered() Dan Carpenter
2014-09-01 17:27 ` Dan Carpenter
2014-09-02 7:02 ` Frans Klaver
2014-09-02 7:02 ` Frans Klaver
2014-09-02 8:54 ` Dan Carpenter [this message]
2014-09-02 8:54 ` Dan Carpenter
2014-09-02 8:57 ` Frans Klaver
2014-09-02 8:57 ` Frans Klaver
2014-09-04 23:03 ` Samuel Ortiz
2014-09-04 23:03 ` Samuel Ortiz
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