* [PATCH v2] net: tulip: check frame size and r/w data length
@ 2020-02-17 11:38 P J P
2020-02-24 5:58 ` Jason Wang
0 siblings, 1 reply; 3+ messages in thread
From: P J P @ 2020-02-17 11:38 UTC (permalink / raw)
To: Sven Schnelle
Cc: Li Qiang, Jason Wang, Qemu Developers, Ziming Zhang, Prasad J Pandit
From: Prasad J Pandit <pjp@fedoraproject.org>
Tulip network driver while copying tx/rx buffers does not check
frame size against r/w data length. This may lead to OOB buffer
access. Add check to avoid it.
Reported-by: Li Qiang <pangpei.lq@antfin.com>
Reported-by: Ziming Zhang <ezrakiez@gmail.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
hw/net/tulip.c | 19 +++++++++++++++++--
1 file changed, 17 insertions(+), 2 deletions(-)
Update v2: retain earlier len[12] & s->rx_frame_len checks
-> https://lists.gnu.org/archive/html/qemu-devel/2020-02/msg04160.html
diff --git a/hw/net/tulip.c b/hw/net/tulip.c
index cfac2719d3..ea4fd371e3 100644
--- a/hw/net/tulip.c
+++ b/hw/net/tulip.c
@@ -170,6 +170,10 @@ static void tulip_copy_rx_bytes(TULIPState *s, struct tulip_descriptor *desc)
} else {
len = s->rx_frame_len;
}
+
+ if (s->rx_frame_len + len >= sizeof(s->rx_frame)) {
+ return;
+ }
pci_dma_write(&s->dev, desc->buf_addr1, s->rx_frame +
(s->rx_frame_size - s->rx_frame_len), len);
s->rx_frame_len -= len;
@@ -181,6 +185,10 @@ static void tulip_copy_rx_bytes(TULIPState *s, struct tulip_descriptor *desc)
} else {
len = s->rx_frame_len;
}
+
+ if (s->rx_frame_len + len >= sizeof(s->rx_frame)) {
+ return;
+ }
pci_dma_write(&s->dev, desc->buf_addr2, s->rx_frame +
(s->rx_frame_size - s->rx_frame_len), len);
s->rx_frame_len -= len;
@@ -227,7 +235,8 @@ static ssize_t tulip_receive(TULIPState *s, const uint8_t *buf, size_t size)
trace_tulip_receive(buf, size);
- if (size < 14 || size > 2048 || s->rx_frame_len || tulip_rx_stopped(s)) {
+ if (size < 14 || size > sizeof(s->rx_frame) - 4
+ || s->rx_frame_len || tulip_rx_stopped(s)) {
return 0;
}
@@ -558,7 +567,7 @@ static void tulip_tx(TULIPState *s, struct tulip_descriptor *desc)
if ((s->csr[6] >> CSR6_OM_SHIFT) & CSR6_OM_MASK) {
/* Internal or external Loopback */
tulip_receive(s, s->tx_frame, s->tx_frame_len);
- } else {
+ } else if (s->tx_frame_len < sizeof(s->tx_frame)) {
qemu_send_packet(qemu_get_queue(s->nic),
s->tx_frame, s->tx_frame_len);
}
@@ -575,12 +584,18 @@ static void tulip_copy_tx_buffers(TULIPState *s, struct tulip_descriptor *desc)
int len1 = (desc->control >> TDES1_BUF1_SIZE_SHIFT) & TDES1_BUF1_SIZE_MASK;
int len2 = (desc->control >> TDES1_BUF2_SIZE_SHIFT) & TDES1_BUF2_SIZE_MASK;
+ if (s->tx_frame_len + len1 >= sizeof(s->tx_frame)) {
+ return;
+ }
if (len1) {
pci_dma_read(&s->dev, desc->buf_addr1,
s->tx_frame + s->tx_frame_len, len1);
s->tx_frame_len += len1;
}
+ if (s->tx_frame_len + len2 >= sizeof(s->tx_frame)) {
+ return;
+ }
if (len2) {
pci_dma_read(&s->dev, desc->buf_addr2,
s->tx_frame + s->tx_frame_len, len2);
--
2.24.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH v2] net: tulip: check frame size and r/w data length
2020-02-17 11:38 [PATCH v2] net: tulip: check frame size and r/w data length P J P
@ 2020-02-24 5:58 ` Jason Wang
2020-03-03 10:57 ` P J P
0 siblings, 1 reply; 3+ messages in thread
From: Jason Wang @ 2020-02-24 5:58 UTC (permalink / raw)
To: P J P, Sven Schnelle
Cc: Li Qiang, Qemu Developers, Ziming Zhang, Prasad J Pandit
On 2020/2/17 下午7:38, P J P wrote:
> From: Prasad J Pandit <pjp@fedoraproject.org>
>
> Tulip network driver while copying tx/rx buffers does not check
> frame size against r/w data length. This may lead to OOB buffer
> access. Add check to avoid it.
>
> Reported-by: Li Qiang <pangpei.lq@antfin.com>
> Reported-by: Ziming Zhang <ezrakiez@gmail.com>
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
> ---
> hw/net/tulip.c | 19 +++++++++++++++++--
> 1 file changed, 17 insertions(+), 2 deletions(-)
>
> Update v2: retain earlier len[12] & s->rx_frame_len checks
> -> https://lists.gnu.org/archive/html/qemu-devel/2020-02/msg04160.html
>
> diff --git a/hw/net/tulip.c b/hw/net/tulip.c
> index cfac2719d3..ea4fd371e3 100644
> --- a/hw/net/tulip.c
> +++ b/hw/net/tulip.c
> @@ -170,6 +170,10 @@ static void tulip_copy_rx_bytes(TULIPState *s, struct tulip_descriptor *desc)
> } else {
> len = s->rx_frame_len;
> }
> +
> + if (s->rx_frame_len + len >= sizeof(s->rx_frame)) {
> + return;
> + }
What's the goal of this checking?
> pci_dma_write(&s->dev, desc->buf_addr1, s->rx_frame +
> (s->rx_frame_size - s->rx_frame_len), len);
> s->rx_frame_len -= len;
> @@ -181,6 +185,10 @@ static void tulip_copy_rx_bytes(TULIPState *s, struct tulip_descriptor *desc)
> } else {
> len = s->rx_frame_len;
> }
> +
> + if (s->rx_frame_len + len >= sizeof(s->rx_frame)) {
> + return;
> + }
> pci_dma_write(&s->dev, desc->buf_addr2, s->rx_frame +
> (s->rx_frame_size - s->rx_frame_len), len);
> s->rx_frame_len -= len;
> @@ -227,7 +235,8 @@ static ssize_t tulip_receive(TULIPState *s, const uint8_t *buf, size_t size)
>
> trace_tulip_receive(buf, size);
>
> - if (size < 14 || size > 2048 || s->rx_frame_len || tulip_rx_stopped(s)) {
> + if (size < 14 || size > sizeof(s->rx_frame) - 4
> + || s->rx_frame_len || tulip_rx_stopped(s)) {
> return 0;
It's better to move those checks in .can_receive().
> }
>
> @@ -558,7 +567,7 @@ static void tulip_tx(TULIPState *s, struct tulip_descriptor *desc)
> if ((s->csr[6] >> CSR6_OM_SHIFT) & CSR6_OM_MASK) {
> /* Internal or external Loopback */
> tulip_receive(s, s->tx_frame, s->tx_frame_len);
> - } else {
> + } else if (s->tx_frame_len < sizeof(s->tx_frame)) {
Should we use <= here?
> qemu_send_packet(qemu_get_queue(s->nic),
> s->tx_frame, s->tx_frame_len);
> }
> @@ -575,12 +584,18 @@ static void tulip_copy_tx_buffers(TULIPState *s, struct tulip_descriptor *desc)
> int len1 = (desc->control >> TDES1_BUF1_SIZE_SHIFT) & TDES1_BUF1_SIZE_MASK;
> int len2 = (desc->control >> TDES1_BUF2_SIZE_SHIFT) & TDES1_BUF2_SIZE_MASK;
>
> + if (s->tx_frame_len + len1 >= sizeof(s->tx_frame)) {
> + return;
> + }
I think it's better to add a return value here to make sure caller
tulip_xmit_list_update() can exit the loop early
> if (len1) {
> pci_dma_read(&s->dev, desc->buf_addr1,
> s->tx_frame + s->tx_frame_len, len1);
> s->tx_frame_len += len1;
> }
>
> + if (s->tx_frame_len + len2 >= sizeof(s->tx_frame)) {
> + return;
> + }
> if (len2) {
> pci_dma_read(&s->dev, desc->buf_addr2,
> s->tx_frame + s->tx_frame_len, len2);
One more thing.
It looks to me there could be a user trigger-able infinite loop in
tun_list_update() through always set TDES0_OWN in its descriptors?
Thanks
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2] net: tulip: check frame size and r/w data length
2020-02-24 5:58 ` Jason Wang
@ 2020-03-03 10:57 ` P J P
0 siblings, 0 replies; 3+ messages in thread
From: P J P @ 2020-03-03 10:57 UTC (permalink / raw)
To: Jason Wang; +Cc: Li Qiang, Sven Schnelle, Qemu Developers, Ziming Zhang
+-- On Mon, 24 Feb 2020, Jason Wang wrote --+
| > + if (s->rx_frame_len + len >= sizeof(s->rx_frame)) {
| > + return;
| > + }
| What's the goal of this checking?
To avoid potential OOB access while in pci_dma_write().
| > pci_dma_write(&s->dev, desc->buf_addr2, s->rx_frame +
| > (s->rx_frame_size - s->rx_frame_len), len);
|
| > + if (size < 14 || size > sizeof(s->rx_frame) - 4
| > + || s->rx_frame_len || tulip_rx_stopped(s)) {
| > return 0;
| It's better to move those checks in .can_receive().
I tried to move these checks to .can_recieve, but tulip_receive()
is called from tulip_receive_nc() and tulip_tx() and the 'size' check could
not be moved to can_receive().
| > + } else if (s->tx_frame_len < sizeof(s->tx_frame)) {
| Should we use <= here?
Done.
| > + if (s->tx_frame_len + len1 >= sizeof(s->tx_frame)) {
| > + return;
| > + }
| I think it's better to add a return value here to make sure caller
| tulip_xmit_list_update() can exit the loop early
Done.
| One more thing.
| It looks to me there could be a user trigger-able infinite loop in
| tun_list_update() through always set TDES0_OWN in its descriptors?
Yes, defined TULIP_DESC_MAX=128 to restrict loop iterations to 128
descriptors to avoid potential infinite loop.
-> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/dec/tulip/tulip.h#n319
Sent patch v3 with above changes; Sorry about the delay.
Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
8685 545E B54C 486B C6EB 271E E285 8B5A F050 DE8D
^ permalink raw reply [flat|nested] 3+ messages in thread
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2020-02-17 11:38 [PATCH v2] net: tulip: check frame size and r/w data length P J P
2020-02-24 5:58 ` Jason Wang
2020-03-03 10:57 ` P J P
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