[PATCH v5 0/3] net: tulip: add checks to avoid OOB access

[PATCH v5 0/3] net: tulip: add checks to avoid OOB access

[P J P]

From: Prasad J Pandit <pjp@fedoraproject.org>

Hello,

* This series adds checks to avoid potential OOB access and infinite loop
  issues while processing rx/tx data.

* Tulip tx descriptors are capped at 128 to avoid infinite loop in
  tulip_xmit_list_update(), wrt Tulip kernel driver
  -> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/dec/tulip/tulip.h#n319

* Update v3: add .can_receive routine
  -> https://lists.gnu.org/archive/html/qemu-devel/2020-02/msg06275.html

* Update v4: flush queued packets once they are received
  -> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg05868.html

* Update v5: fixed a typo in patch commit message
  -> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg06209.html

Thank you.
--
Prasad J Pandit (3):
  net: tulip: check frame size and r/w data length
  net: tulip: add .can_receive routine
  net: tulip: flush queued packets post receive

 hw/net/tulip.c | 51 +++++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 42 insertions(+), 9 deletions(-)

--
2.25.1

[PATCH v5 1/3] net: tulip: check frame size and r/w data length

[P J P]

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.

Limit iterations over descriptors to avoid potential infinite
loop issue in tulip_xmit_list_update.

Reported-by: Li Qiang <pangpei.lq@antfin.com>
Reported-by: Ziming Zhang <ezrakiez@gmail.com>
Reported-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
 hw/net/tulip.c | 36 +++++++++++++++++++++++++++---------
 1 file changed, 27 insertions(+), 9 deletions(-)

Update v3: return a value from tulip_copy_tx_buffers() and avoid infinite loop
  -> https://lists.gnu.org/archive/html/qemu-devel/2020-02/msg06275.html

diff --git a/hw/net/tulip.c b/hw/net/tulip.c
index cfac2719d3..fbe40095da 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;
     }
 
@@ -275,7 +284,6 @@ static ssize_t tulip_receive_nc(NetClientState *nc,
     return tulip_receive(qemu_get_nic_opaque(nc), buf, size);
 }
 
-
 static NetClientInfo net_tulip_info = {
     .type = NET_CLIENT_DRIVER_NIC,
     .size = sizeof(NICState),
@@ -558,7 +566,7 @@ 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);
         }
@@ -570,23 +578,31 @@ static void tulip_tx(TULIPState *s, struct tulip_descriptor *desc)
     }
 }
 
-static void tulip_copy_tx_buffers(TULIPState *s, struct tulip_descriptor *desc)
+static int 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 -1;
+    }
     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 -1;
+    }
     if (len2) {
         pci_dma_read(&s->dev, desc->buf_addr2,
             s->tx_frame + s->tx_frame_len, len2);
         s->tx_frame_len += len2;
     }
     desc->status = (len1 + len2) ? 0 : 0x7fffffff;
+
+    return 0;
 }
 
 static void tulip_setup_filter_addr(TULIPState *s, uint8_t *buf, int n)
@@ -651,13 +667,15 @@ static uint32_t tulip_ts(TULIPState *s)
 
 static void tulip_xmit_list_update(TULIPState *s)
 {
+#define TULIP_DESC_MAX 128
+    uint8_t i = 0;
     struct tulip_descriptor desc;
 
     if (tulip_ts(s) != CSR5_TS_SUSPENDED) {
         return;
     }
 
-    for (;;) {
+    for (i = 0; i < TULIP_DESC_MAX; i++) {
         tulip_desc_read(s, s->current_tx_desc, &desc);
         tulip_dump_tx_descriptor(s, &desc);
 
@@ -675,10 +693,10 @@ static void tulip_xmit_list_update(TULIPState *s)
                 s->tx_frame_len = 0;
             }
 
-            tulip_copy_tx_buffers(s, &desc);
-
-            if (desc.control & TDES1_LS) {
-                tulip_tx(s, &desc);
+            if (!tulip_copy_tx_buffers(s, &desc)) {
+                if (desc.control & TDES1_LS) {
+                    tulip_tx(s, &desc);
+                }
             }
         }
         tulip_desc_write(s, s->current_tx_desc, &desc);
-- 
2.25.1

[PATCH v5 2/3] net: tulip: add .can_receive routine

[P J P]

From: Prasad J Pandit <pjp@fedoraproject.org>

Define .can_receive routine to do sanity checks before receiving
packet data.

Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
 hw/net/tulip.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

Update v3: define .can_receive routine
  -> https://lists.gnu.org/archive/html/qemu-devel/2020-02/msg06275.html

Update v5: fix a typo in commit log message
  -> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg06209.html

diff --git a/hw/net/tulip.c b/hw/net/tulip.c
index fbe40095da..757f12c710 100644
--- a/hw/net/tulip.c
+++ b/hw/net/tulip.c
@@ -229,6 +229,18 @@ static bool tulip_filter_address(TULIPState *s, const uint8_t *addr)
     return ret;
 }
 
+static int
+tulip_can_receive(NetClientState *nc)
+{
+    TULIPState *s = qemu_get_nic_opaque(nc);
+
+    if (s->rx_frame_len || tulip_rx_stopped(s)) {
+        return false;
+    }
+
+    return true;
+}
+
 static ssize_t tulip_receive(TULIPState *s, const uint8_t *buf, size_t size)
 {
     struct tulip_descriptor desc;
@@ -236,7 +248,7 @@ static ssize_t tulip_receive(TULIPState *s, const uint8_t *buf, size_t size)
     trace_tulip_receive(buf, size);
 
     if (size < 14 || size > sizeof(s->rx_frame) - 4
-        || s->rx_frame_len || tulip_rx_stopped(s)) {
+        || !tulip_can_receive(s->nic->ncs)) {
         return 0;
     }
 
@@ -288,6 +300,7 @@ static NetClientInfo net_tulip_info = {
     .type = NET_CLIENT_DRIVER_NIC,
     .size = sizeof(NICState),
     .receive = tulip_receive_nc,
+    .can_receive = tulip_can_receive,
 };
 
 static const char *tulip_reg_name(const hwaddr addr)
-- 
2.25.1

[PATCH v5 3/3] net: tulip: flush queued packets post receive

[P J P]

From: Prasad J Pandit <pjp@fedoraproject.org>

Call qemu_flush_queued_packets to flush queued packets once they
are read in tulip_receive().

Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
---
 hw/net/tulip.c | 2 ++
 1 file changed, 2 insertions(+)

Update v4: call qemu_flush_queued_packets()
  -> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg05868.html

diff --git a/hw/net/tulip.c b/hw/net/tulip.c
index 757f12c710..8d8c9519e7 100644
--- a/hw/net/tulip.c
+++ b/hw/net/tulip.c
@@ -287,6 +287,8 @@ static ssize_t tulip_receive(TULIPState *s, const uint8_t *buf, size_t size)
         tulip_desc_write(s, s->current_rx_desc, &desc);
         tulip_next_rx_descriptor(s, &desc);
     } while (s->rx_frame_len);
+
+    qemu_flush_queued_packets(qemu_get_queue(s->nic));
     return size;
 }
 
-- 
2.25.1

Re: [PATCH v5 2/3] net: tulip: add .can_receive routine

[Philippe Mathieu-Daudé]

On 3/19/20 6:40 PM, P J P wrote:
> From: Prasad J Pandit <pjp@fedoraproject.org>
> 
> Define .can_receive routine to do sanity checks before receiving
> packet data.
> 
> Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
> ---
>   hw/net/tulip.c | 15 ++++++++++++++-
>   1 file changed, 14 insertions(+), 1 deletion(-)
> 
> Update v3: define .can_receive routine
>    -> https://lists.gnu.org/archive/html/qemu-devel/2020-02/msg06275.html
> 
> Update v5: fix a typo in commit log message
>    -> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg06209.html
> 
> diff --git a/hw/net/tulip.c b/hw/net/tulip.c
> index fbe40095da..757f12c710 100644
> --- a/hw/net/tulip.c
> +++ b/hw/net/tulip.c
> @@ -229,6 +229,18 @@ static bool tulip_filter_address(TULIPState *s, const uint8_t *addr)
>       return ret;
>   }
>   
> +static int
> +tulip_can_receive(NetClientState *nc)
> +{
> +    TULIPState *s = qemu_get_nic_opaque(nc);
> +
> +    if (s->rx_frame_len || tulip_rx_stopped(s)) {
> +        return false;
> +    }
> +
> +    return true;
> +}
> +
>   static ssize_t tulip_receive(TULIPState *s, const uint8_t *buf, size_t size)
>   {
>       struct tulip_descriptor desc;
> @@ -236,7 +248,7 @@ static ssize_t tulip_receive(TULIPState *s, const uint8_t *buf, size_t size)
>       trace_tulip_receive(buf, size);
>   
>       if (size < 14 || size > sizeof(s->rx_frame) - 4
> -        || s->rx_frame_len || tulip_rx_stopped(s)) {
> +        || !tulip_can_receive(s->nic->ncs)) {
>           return 0;
>       }
>   
> @@ -288,6 +300,7 @@ static NetClientInfo net_tulip_info = {
>       .type = NET_CLIENT_DRIVER_NIC,
>       .size = sizeof(NICState),
>       .receive = tulip_receive_nc,
> +    .can_receive = tulip_can_receive,
>   };
>   
>   static const char *tulip_reg_name(const hwaddr addr)
> 

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Re: [PATCH v5 0/3] net: tulip: add checks to avoid OOB access

[Jason Wang]

On 2020/3/20 上午1:40, P J P wrote:
> From: Prasad J Pandit <pjp@fedoraproject.org>
>
> Hello,
>
> * This series adds checks to avoid potential OOB access and infinite loop
>    issues while processing rx/tx data.
>
> * Tulip tx descriptors are capped at 128 to avoid infinite loop in
>    tulip_xmit_list_update(), wrt Tulip kernel driver
>    -> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/dec/tulip/tulip.h#n319
>
> * Update v3: add .can_receive routine
>    -> https://lists.gnu.org/archive/html/qemu-devel/2020-02/msg06275.html
>
> * Update v4: flush queued packets once they are received
>    -> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg05868.html
>
> * Update v5: fixed a typo in patch commit message
>    -> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg06209.html
>
> Thank you.


Looks good to me.

Qiang, any change to give a test with your reproducer?

Thanks


> --
> Prasad J Pandit (3):
>    net: tulip: check frame size and r/w data length
>    net: tulip: add .can_receive routine
>    net: tulip: flush queued packets post receive
>
>   hw/net/tulip.c | 51 +++++++++++++++++++++++++++++++++++++++++---------
>   1 file changed, 42 insertions(+), 9 deletions(-)
>
> --
> 2.25.1
>
>

Re: [PATCH v5 0/3] net: tulip: add checks to avoid OOB access

[Jason Wang]

On 2020/3/23 上午11:43, Jason Wang wrote:
>
> On 2020/3/20 上午1:40, P J P wrote:
>> From: Prasad J Pandit <pjp@fedoraproject.org>
>>
>> Hello,
>>
>> * This series adds checks to avoid potential OOB access and infinite 
>> loop
>>    issues while processing rx/tx data.
>>
>> * Tulip tx descriptors are capped at 128 to avoid infinite loop in
>>    tulip_xmit_list_update(), wrt Tulip kernel driver
>>    -> 
>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/dec/tulip/tulip.h#n319
>>
>> * Update v3: add .can_receive routine
>>    -> 
>> https://lists.gnu.org/archive/html/qemu-devel/2020-02/msg06275.html
>>
>> * Update v4: flush queued packets once they are received
>>    -> 
>> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg05868.html
>>
>> * Update v5: fixed a typo in patch commit message
>>    -> 
>> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg06209.html
>>
>> Thank you.
>
>
> Looks good to me.
>
> Qiang, any change to give a test with your reproducer?
>
> Thanks


Ok, I get this:

hw/net/tulip.c:305:20: error: initialization of ‘_Bool 
(*)(NetClientState *)’ {aka ‘_Bool (*)(struct NetClientState *)’} from 
incompatible pointer type ‘int (*)(NetClientState *)’ {aka ‘int 
(*)(struct NetClientState *)’} [-Werror=incompatible-pointer-types]
      .can_receive = tulip_can_receive,
                     ^~~~~~~~~~~~~~~~~

Prasad, please fix this and post a new version.

While at it, I prefer to squash patch 3 into patch 2 since patch 3 fixes 
the issue introduced by patch 2.

Thanks


>
>
>> -- 
>> Prasad J Pandit (3):
>>    net: tulip: check frame size and r/w data length
>>    net: tulip: add .can_receive routine
>>    net: tulip: flush queued packets post receive
>>
>>   hw/net/tulip.c | 51 +++++++++++++++++++++++++++++++++++++++++---------
>>   1 file changed, 42 insertions(+), 9 deletions(-)
>>
>> -- 
>> 2.25.1
>>
>>

Re: [PATCH v5 0/3] net: tulip: add checks to avoid OOB access

[P J P]

[-- Attachment #1: Type: text/plain, Size: 789 bytes --]

+-- On Mon, 23 Mar 2020, Jason Wang wrote --+
| hw/net/tulip.c:305:20: error: initialization of ‘_Bool (*)(NetClientState *)’
| {aka ‘_Bool (*)(struct NetClientState *)’} from incompatible pointer type ‘int
| (*)(NetClientState *)’ {aka ‘int (*)(struct NetClientState *)’}
| [-Werror=incompatible-pointer-types]
|      .can_receive = tulip_can_receive,
|                     ^~~~~~~~~~~~~~~~~

Strange, I did not get it.

| Prasad, please fix this and post a new version.
| 
| While at it, I prefer to squash patch 3 into patch 2 since patch 3 fixes the
| issue introduced by patch 2.

Okay, sending your way shortly.

Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
8685 545E B54C 486B C6EB 271E E285 8B5A F050 DE8D

Re: [PATCH v5 0/3] net: tulip: add checks to avoid OOB access

[P J P]

[-- Attachment #1: Type: text/plain, Size: 1425 bytes --]

+-- On Mon, 23 Mar 2020, P J P wrote --+
| +-- On Mon, 23 Mar 2020, Jason Wang wrote --+
| | hw/net/tulip.c:305:20: error: initialization of ‘_Bool (*)(NetClientState *)’
| | {aka ‘_Bool (*)(struct NetClientState *)’} from incompatible pointer type ‘int
| | (*)(NetClientState *)’ {aka ‘int (*)(struct NetClientState *)’}
| | [-Werror=incompatible-pointer-types]
| |      .can_receive = tulip_can_receive,
| |                     ^~~~~~~~~~~~~~~~~
| 
| Strange, I did not get it.

qemu/include/net.h:

  typedef int (NetCanReceive)(NetClientState *);

  typedef struct NetClientInfo {
    ...
    NetCanReceive *can_receive;
    ...
  }

@Jason,
  Looking at the definition above, 'NetCanReceive' is returning an 'int' type. 
When I change 'tulip_can_receive' to return a 'bool', I get the reverse error

hw/net/tulip.c:305:20: error: initialization of ‘int (*)(NetClientState *)’ {aka ‘int (*)(struct NetClientState *)’} from incompatible pointer type ‘_Bool (*)(NetClientState *)’ {aka ‘_Bool (*)(struct NetClientState *)’} 
[-Werror=incompatible-pointer-types]
  305 |     .can_receive = tulip_can_receive,
      |                    ^~~~~~~~~~~~~~~~~

Maybe because of a stagged local change in your tree? (to confirm)

Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
8685 545E B54C 486B C6EB 271E E285 8B5A F050 DE8D

Re: [PATCH v5 0/3] net: tulip: add checks to avoid OOB access

[Li Qiang]

[-- Attachment #1: Type: text/plain, Size: 1661 bytes --]

Jason Wang <jasowang@redhat.com> 于2020年3月23日周一 上午11:44写道：

>
> On 2020/3/20 上午1:40, P J P wrote:
> > From: Prasad J Pandit <pjp@fedoraproject.org>
> >
> > Hello,
> >
> > * This series adds checks to avoid potential OOB access and infinite loop
> >    issues while processing rx/tx data.
> >
> > * Tulip tx descriptors are capped at 128 to avoid infinite loop in
> >    tulip_xmit_list_update(), wrt Tulip kernel driver
> >    ->
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/net/ethernet/dec/tulip/tulip.h#n319
> >
> > * Update v3: add .can_receive routine
> >    ->
> https://lists.gnu.org/archive/html/qemu-devel/2020-02/msg06275.html
> >
> > * Update v4: flush queued packets once they are received
> >    ->
> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg05868.html
> >
> > * Update v5: fixed a typo in patch commit message
> >    ->
> https://lists.gnu.org/archive/html/qemu-devel/2020-03/msg06209.html
> >
> > Thank you.
>
>
> Looks good to me.
>
> Qiang, any change to give a test with your reproducer?
>
>
Hi Jason,
Sorry for missing discussing this thread as so busy these days/weeks.

I will try to test this patch asap.

Thanks,
Li Qiang



> Thanks
>
>
> > --
> > Prasad J Pandit (3):
> >    net: tulip: check frame size and r/w data length
> >    net: tulip: add .can_receive routine
> >    net: tulip: flush queued packets post receive
> >
> >   hw/net/tulip.c | 51 +++++++++++++++++++++++++++++++++++++++++---------
> >   1 file changed, 42 insertions(+), 9 deletions(-)
> >
> > --
> > 2.25.1
> >
> >
>
>
>

[-- Attachment #2: Type: text/html, Size: 3010 bytes --]

Re: [PATCH v5 0/3] net: tulip: add checks to avoid OOB access

[Jason Wang]

On 2020/3/23 下午1:40, P J P wrote:
> +-- On Mon, 23 Mar 2020, P J P wrote --+
> | +-- On Mon, 23 Mar 2020, Jason Wang wrote --+
> | | hw/net/tulip.c:305:20: error: initialization of ‘_Bool (*)(NetClientState *)’
> | | {aka ‘_Bool (*)(struct NetClientState *)’} from incompatible pointer type ‘int
> | | (*)(NetClientState *)’ {aka ‘int (*)(struct NetClientState *)’}
> | | [-Werror=incompatible-pointer-types]
> | |      .can_receive = tulip_can_receive,
> | |                     ^~~~~~~~~~~~~~~~~
> |
> | Strange, I did not get it.
>
> qemu/include/net.h:
>
>    typedef int (NetCanReceive)(NetClientState *);
>
>    typedef struct NetClientInfo {
>      ...
>      NetCanReceive *can_receive;
>      ...
>    }
>
> @Jason,
>    Looking at the definition above, 'NetCanReceive' is returning an 'int' type.
> When I change 'tulip_can_receive' to return a 'bool', I get the reverse error
>
> hw/net/tulip.c:305:20: error: initialization of ‘int (*)(NetClientState *)’ {aka ‘int (*)(struct NetClientState *)’} from incompatible pointer type ‘_Bool (*)(NetClientState *)’ {aka ‘_Bool (*)(struct NetClientState *)’}
> [-Werror=incompatible-pointer-types]
>    305 |     .can_receive = tulip_can_receive,
>        |                    ^~~~~~~~~~~~~~~~~
>
> Maybe because of a stagged local change in your tree? (to confirm)


Right, it's the conversion from int to bool done by Philippe :)

I will fix the conflict after Qiang tests it.

Thanks


>
> Thank you.
> --
> Prasad J Pandit / Red Hat Product Security Team
> 8685 545E B54C 486B C6EB 271E E285 8B5A F050 DE8D

Re: [PATCH v5 0/3] net: tulip: add checks to avoid OOB access

[P J P]

+-- On Mon, 23 Mar 2020, Jason Wang wrote --+
| Prasad, please fix this and post a new version.
| 
| While at it, I prefer to squash patch 3 into patch 2 since patch 3 fixes the 
| issue introduced by patch 2.

Sent patch v6.

Thank you.
--
Prasad J Pandit / Red Hat Product Security Team
8685 545E B54C 486B C6EB 271E E285 8B5A F050 DE8D