* [PATCH] nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION
@ 2021-11-17 17:17 Jordy Zomer
2021-11-18 7:04 ` [PATCH v2] " Jordy Zomer
2022-01-11 16:44 ` [PATCH v3] " Jordy Zomer
0 siblings, 2 replies; 6+ messages in thread
From: Jordy Zomer @ 2021-11-17 17:17 UTC (permalink / raw)
To: linux-kernel; +Cc: Jordy Zomer, Krzysztof Kozlowski, Jakub Kicinski, netdev
It appears that there are some buffer overflows in EVT_TRANSACTION.
This happens because the length parameters that are passed to memcpy
come directly from skb->data and are not guarded in any way.
It would be nice if someone can review and test this patch because
I don't own the hardware :)
Signed-off-by: Jordy Zomer <jordy@pwning.systems>
---
drivers/nfc/st21nfca/se.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/nfc/st21nfca/se.c b/drivers/nfc/st21nfca/se.c
index a43fc4117fa5..e3483aca3280 100644
--- a/drivers/nfc/st21nfca/se.c
+++ b/drivers/nfc/st21nfca/se.c
@@ -316,6 +316,11 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
return -ENOMEM;
transaction->aid_len = skb->data[1];
+
+ // Checking if the length of the AID is valid
+ if (transaction->aid_len > sizeof(transaction->aid))
+ return -EINVAL;
+
memcpy(transaction->aid, &skb->data[2],
transaction->aid_len);
@@ -325,6 +330,14 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
return -EPROTO;
transaction->params_len = skb->data[transaction->aid_len + 3];
+
+ // check if the length of the parameters is valid
+ // we can't use sizeof(transaction->params) because it's
+ // a flexible array member so we have to check if params_len
+ // is bigger than the space allocated for the array
+ if (transaction->params_len > ((skb->len - 2) - sizeof(struct nfc_evt_transaction)))
+ return -EINVAL;
+
memcpy(transaction->params, skb->data +
transaction->aid_len + 4, transaction->params_len);
--
2.27.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH v2] nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION
2021-11-17 17:17 [PATCH] nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION Jordy Zomer
@ 2021-11-18 7:04 ` Jordy Zomer
2021-11-18 7:40 ` Krzysztof Kozlowski
2022-01-11 16:44 ` [PATCH v3] " Jordy Zomer
1 sibling, 1 reply; 6+ messages in thread
From: Jordy Zomer @ 2021-11-18 7:04 UTC (permalink / raw)
To: linux-kernel; +Cc: Jordy Zomer, Krzysztof Kozlowski, Jakub Kicinski, netdev
It appears that there are some buffer overflows in EVT_TRANSACTION.
This happens because the length parameters that are passed to memcpy
come directly from skb->data and are not guarded in any way.
It would be nice if someone can review and test this patch because
I don't own the hardware :)
EDIT: Changed the comment styles and removed double newlines
Signed-off-by: Jordy Zomer <jordy@pwning.systems>
---
drivers/nfc/st21nfca/se.c | 15 +++++++++++++++
1 file changed, 15 insertions(+)
diff --git a/drivers/nfc/st21nfca/se.c b/drivers/nfc/st21nfca/se.c
index a43fc4117fa5..5e036768b2a1 100644
--- a/drivers/nfc/st21nfca/se.c
+++ b/drivers/nfc/st21nfca/se.c
@@ -316,6 +316,11 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
return -ENOMEM;
transaction->aid_len = skb->data[1];
+
+ /* Checking if the length of the AID is valid */
+ if (transaction->aid_len > sizeof(transaction->aid))
+ return -EINVAL;
+
memcpy(transaction->aid, &skb->data[2],
transaction->aid_len);
@@ -325,6 +330,16 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
return -EPROTO;
transaction->params_len = skb->data[transaction->aid_len + 3];
+
+ /*
+ * check if the length of the parameters is valid
+ * we can't use sizeof(transaction->params) because it's
+ * a flexible array member so we have to check if params_len
+ * is bigger than the space allocated for the array
+ */
+ if (transaction->params_len > ((skb->len - 2) - sizeof(struct nfc_evt_transaction)))
+ return -EINVAL;
+
memcpy(transaction->params, skb->data +
transaction->aid_len + 4, transaction->params_len);
--
2.27.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v2] nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION
2021-11-18 7:04 ` [PATCH v2] " Jordy Zomer
@ 2021-11-18 7:40 ` Krzysztof Kozlowski
0 siblings, 0 replies; 6+ messages in thread
From: Krzysztof Kozlowski @ 2021-11-18 7:40 UTC (permalink / raw)
To: Jordy Zomer, linux-kernel; +Cc: Jakub Kicinski, netdev
On 18/11/2021 08:04, Jordy Zomer wrote:
> It appears that there are some buffer overflows in EVT_TRANSACTION.
> This happens because the length parameters that are passed to memcpy
> come directly from skb->data and are not guarded in any way.
>
> It would be nice if someone can review and test this patch because
> I don't own the hardware :)
>
> EDIT: Changed the comment styles and removed double newlines
>
Same comments apply. :)
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH v3] nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION
2021-11-17 17:17 [PATCH] nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION Jordy Zomer
2021-11-18 7:04 ` [PATCH v2] " Jordy Zomer
@ 2022-01-11 16:44 ` Jordy Zomer
2022-01-12 10:07 ` Krzysztof Kozlowski
1 sibling, 1 reply; 6+ messages in thread
From: Jordy Zomer @ 2022-01-11 16:44 UTC (permalink / raw)
To: jordy; +Cc: krzysztof.kozlowski, kuba, linux-kernel, netdev
It appears that there are some buffer overflows in EVT_TRANSACTION.
This happens because the length parameters that are passed to memcpy
come directly from skb->data and are not guarded in any way.
Signed-off-by: Jordy Zomer <jordy@pwning.systems>
---
drivers/nfc/st21nfca/se.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/nfc/st21nfca/se.c b/drivers/nfc/st21nfca/se.c
index a43fc4117fa5..c922f10d0d7b 100644
--- a/drivers/nfc/st21nfca/se.c
+++ b/drivers/nfc/st21nfca/se.c
@@ -316,6 +316,11 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
return -ENOMEM;
transaction->aid_len = skb->data[1];
+
+ /* Checking if the length of the AID is valid */
+ if (transaction->aid_len > sizeof(transaction->aid))
+ return -EINVAL;
+
memcpy(transaction->aid, &skb->data[2],
transaction->aid_len);
@@ -325,6 +330,11 @@ int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
return -EPROTO;
transaction->params_len = skb->data[transaction->aid_len + 3];
+
+ /* Total size is allocated (skb->len - 2) minus fixed array members */
+ if (transaction->params_len > ((skb->len - 2) - sizeof(struct nfc_evt_transaction)))
+ return -EINVAL;
+
memcpy(transaction->params, skb->data +
transaction->aid_len + 4, transaction->params_len);
--
2.27.0
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH v3] nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION
2022-01-11 16:44 ` [PATCH v3] " Jordy Zomer
@ 2022-01-12 10:07 ` Krzysztof Kozlowski
2022-01-12 17:25 ` Jakub Kicinski
0 siblings, 1 reply; 6+ messages in thread
From: Krzysztof Kozlowski @ 2022-01-12 10:07 UTC (permalink / raw)
To: Jordy Zomer; +Cc: kuba, linux-kernel, netdev
On 11/01/2022 17:44, Jordy Zomer wrote:
> It appears that there are some buffer overflows in EVT_TRANSACTION.
> This happens because the length parameters that are passed to memcpy
> come directly from skb->data and are not guarded in any way.
>
> Signed-off-by: Jordy Zomer <jordy@pwning.systems>
> ---
> drivers/nfc/st21nfca/se.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
Looks ok.
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH v3] nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION
2022-01-12 10:07 ` Krzysztof Kozlowski
@ 2022-01-12 17:25 ` Jakub Kicinski
0 siblings, 0 replies; 6+ messages in thread
From: Jakub Kicinski @ 2022-01-12 17:25 UTC (permalink / raw)
To: Krzysztof Kozlowski; +Cc: Jordy Zomer, linux-kernel, netdev
On Wed, 12 Jan 2022 11:07:34 +0100 Krzysztof Kozlowski wrote:
> On 11/01/2022 17:44, Jordy Zomer wrote:
> > It appears that there are some buffer overflows in EVT_TRANSACTION.
> > This happens because the length parameters that are passed to memcpy
> > come directly from skb->data and are not guarded in any way.
> >
> > Signed-off-by: Jordy Zomer <jordy@pwning.systems>
>
> Looks ok.
>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Thanks! I believe this is commit 4fbcc1a4cb20 ("nfc: st21nfca: Fix
potential buffer overflows in EVT_TRANSACTION") in net.
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-01-12 17:26 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2021-11-17 17:17 [PATCH] nfc: st21nfca: Fix potential buffer overflows in EVT_TRANSACTION Jordy Zomer
2021-11-18 7:04 ` [PATCH v2] " Jordy Zomer
2021-11-18 7:40 ` Krzysztof Kozlowski
2022-01-11 16:44 ` [PATCH v3] " Jordy Zomer
2022-01-12 10:07 ` Krzysztof Kozlowski
2022-01-12 17:25 ` Jakub Kicinski
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