diff mbox series

IB/hfi1: Fix sdma.h tx->num_descs off-by-one error (take two)

Message ID 20240126152125.869509-1-neelx@redhat.com
State New
Headers
Series IB/hfi1: Fix sdma.h tx->num_descs off-by-one error (take two) |

Commit Message

Daniel Vacek Jan. 26, 2024, 3:21 p.m. UTC 
  Unfortunately the commit `fd8958efe877` introduced another error
causing the `descs` array to overflow. This reults in further crashes
easily reproducible by `sendmsg` system call.

[ 1080.836473] general protection fault, probably for non-canonical address 0x400300015528b00a: 0000 [#1] PREEMPT SMP PTI
[ 1080.869326] RIP: 0010:hfi1_ipoib_build_ib_tx_headers.constprop.0+0xe1/0x2b0 [hfi1]
--
[ 1080.974535] Call Trace:
[ 1080.976990]  <TASK>
[ 1081.021929]  hfi1_ipoib_send_dma_common+0x7a/0x2e0 [hfi1]
[ 1081.027364]  hfi1_ipoib_send_dma_list+0x62/0x270 [hfi1]
[ 1081.032633]  hfi1_ipoib_send+0x112/0x300 [hfi1]
[ 1081.042001]  ipoib_start_xmit+0x2a9/0x2d0 [ib_ipoib]
[ 1081.046978]  dev_hard_start_xmit+0xc4/0x210
--
[ 1081.148347]  __sys_sendmsg+0x59/0xa0

crash> ipoib_txreq 0xffff9cfeba229f00
struct ipoib_txreq {
  txreq = {
    list = {
      next = 0xffff9cfeba229f00,
      prev = 0xffff9cfeba229f00
    },
    descp = 0xffff9cfeba229f40,
    coalesce_buf = 0x0,
    wait = 0xffff9cfea4e69a48,
    complete = 0xffffffffc0fe0760 <hfi1_ipoib_sdma_complete>,
    packet_len = 0x46d,
    tlen = 0x0,
    num_desc = 0x0,
    desc_limit = 0x6,
    next_descq_idx = 0x45c,
    coalesce_idx = 0x0,
    flags = 0x0,
    descs = {{
        qw = {0x8024000120dffb00, 0x4}  # SDMA_DESC0_FIRST_DESC_FLAG (bit 63)
      }, {
        qw = {  0x3800014231b108, 0x4}
      }, {
        qw = { 0x310000e4ee0fcf0, 0x8}
      }, {
        qw = {  0x3000012e9f8000, 0x8}
      }, {
        qw = {  0x59000dfb9d0000, 0x8}
      }, {
        qw = {  0x78000e02e40000, 0x8}
      }}
  },
  sdma_hdr =  0x400300015528b000,  <<< invalid pointer in the tx request structure
  sdma_status = 0x0,                   SDMA_DESC0_LAST_DESC_FLAG (bit 62)
  complete = 0x0,
  priv = 0x0,
  txq = 0xffff9cfea4e69880,
  skb = 0xffff9d099809f400
}

With this patch the crashes are no longer reproducible and the machine is stable.

Note, the header file changes are just an unrelated clean-up while I was looking
around trying to find the bug.

Fixes: fd8958efe877 ("IB/hfi1: Fix sdma.h tx->num_descs off-by-one errors")
Cc: stable@vger.kernel.org
Reported-by: Mats Kronberg <kronberg@nsc.liu.se>
Tested-by: Mats Kronberg <kronberg@nsc.liu.se>
Signed-off-by: Daniel Vacek <neelx@redhat.com>
---
 drivers/infiniband/hw/hfi1/sdma.c |  2 +-
 drivers/infiniband/hw/hfi1/sdma.h | 17 +++++++----------
 2 files changed, 8 insertions(+), 11 deletions(-)

Comments

Leon Romanovsky Jan. 31, 2024, 12:50 p.m. UTC | #1 
On Fri, Jan 26, 2024 at 04:21:23PM +0100, Daniel Vacek wrote:
> Unfortunately the commit `fd8958efe877` introduced another error
> causing the `descs` array to overflow. This reults in further crashes
> easily reproducible by `sendmsg` system call.
> 
> [ 1080.836473] general protection fault, probably for non-canonical address 0x400300015528b00a: 0000 [#1] PREEMPT SMP PTI
> [ 1080.869326] RIP: 0010:hfi1_ipoib_build_ib_tx_headers.constprop.0+0xe1/0x2b0 [hfi1]
> --
> [ 1080.974535] Call Trace:
> [ 1080.976990]  <TASK>
> [ 1081.021929]  hfi1_ipoib_send_dma_common+0x7a/0x2e0 [hfi1]
> [ 1081.027364]  hfi1_ipoib_send_dma_list+0x62/0x270 [hfi1]
> [ 1081.032633]  hfi1_ipoib_send+0x112/0x300 [hfi1]
> [ 1081.042001]  ipoib_start_xmit+0x2a9/0x2d0 [ib_ipoib]
> [ 1081.046978]  dev_hard_start_xmit+0xc4/0x210
> --
> [ 1081.148347]  __sys_sendmsg+0x59/0xa0
> 
> crash> ipoib_txreq 0xffff9cfeba229f00
> struct ipoib_txreq {
>   txreq = {
>     list = {
>       next = 0xffff9cfeba229f00,
>       prev = 0xffff9cfeba229f00
>     },
>     descp = 0xffff9cfeba229f40,
>     coalesce_buf = 0x0,
>     wait = 0xffff9cfea4e69a48,
>     complete = 0xffffffffc0fe0760 <hfi1_ipoib_sdma_complete>,
>     packet_len = 0x46d,
>     tlen = 0x0,
>     num_desc = 0x0,
>     desc_limit = 0x6,
>     next_descq_idx = 0x45c,
>     coalesce_idx = 0x0,
>     flags = 0x0,
>     descs = {{
>         qw = {0x8024000120dffb00, 0x4}  # SDMA_DESC0_FIRST_DESC_FLAG (bit 63)
>       }, {
>         qw = {  0x3800014231b108, 0x4}
>       }, {
>         qw = { 0x310000e4ee0fcf0, 0x8}
>       }, {
>         qw = {  0x3000012e9f8000, 0x8}
>       }, {
>         qw = {  0x59000dfb9d0000, 0x8}
>       }, {
>         qw = {  0x78000e02e40000, 0x8}
>       }}
>   },
>   sdma_hdr =  0x400300015528b000,  <<< invalid pointer in the tx request structure
>   sdma_status = 0x0,                   SDMA_DESC0_LAST_DESC_FLAG (bit 62)
>   complete = 0x0,
>   priv = 0x0,
>   txq = 0xffff9cfea4e69880,
>   skb = 0xffff9d099809f400
> }
> 
> With this patch the crashes are no longer reproducible and the machine is stable.
> 
> Note, the header file changes are just an unrelated clean-up while I was looking
> around trying to find the bug.
> 
> Fixes: fd8958efe877 ("IB/hfi1: Fix sdma.h tx->num_descs off-by-one errors")
> Cc: stable@vger.kernel.org
> Reported-by: Mats Kronberg <kronberg@nsc.liu.se>
> Tested-by: Mats Kronberg <kronberg@nsc.liu.se>
> Signed-off-by: Daniel Vacek <neelx@redhat.com>
> ---
>  drivers/infiniband/hw/hfi1/sdma.c |  2 +-
>  drivers/infiniband/hw/hfi1/sdma.h | 17 +++++++----------
>  2 files changed, 8 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c
> index 6e5ac2023328a..b67d23b1f2862 100644
> --- a/drivers/infiniband/hw/hfi1/sdma.c
> +++ b/drivers/infiniband/hw/hfi1/sdma.c
> @@ -3158,7 +3158,7 @@ int _pad_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx)
>  {
>  	int rval = 0;
>  
> -	if ((unlikely(tx->num_desc + 1 == tx->desc_limit))) {
> +	if ((unlikely(tx->num_desc == tx->desc_limit))) {

Maybe, Dennis?

>  		rval = _extend_sdma_tx_descs(dd, tx);
>  		if (rval) {
>  			__sdma_txclean(dd, tx);
> diff --git a/drivers/infiniband/hw/hfi1/sdma.h b/drivers/infiniband/hw/hfi1/sdma.h
> index d77246b48434f..362815a8da267 100644
> --- a/drivers/infiniband/hw/hfi1/sdma.h
> +++ b/drivers/infiniband/hw/hfi1/sdma.h
> @@ -639,13 +639,13 @@ static inline void sdma_txclean(struct hfi1_devdata *dd, struct sdma_txreq *tx)
>  static inline void _sdma_close_tx(struct hfi1_devdata *dd,
>  				  struct sdma_txreq *tx)
>  {
> -	u16 last_desc = tx->num_desc - 1;
> +	struct sdma_desc *desc = &tx->descp[tx->num_desc - 1];
>  
> -	tx->descp[last_desc].qw[0] |= SDMA_DESC0_LAST_DESC_FLAG;
> -	tx->descp[last_desc].qw[1] |= dd->default_desc1;
> +	desc->qw[0] |= SDMA_DESC0_LAST_DESC_FLAG;
> +	desc->qw[1] |= dd->default_desc1;
>  	if (tx->flags & SDMA_TXREQ_F_URGENT)
> -		tx->descp[last_desc].qw[1] |= (SDMA_DESC1_HEAD_TO_HOST_FLAG |
> -					       SDMA_DESC1_INT_REQ_FLAG);
> +		desc->qw[1] |= (SDMA_DESC1_HEAD_TO_HOST_FLAG |
> +				SDMA_DESC1_INT_REQ_FLAG);

Unrelated change which doesn't change anything.

>  }
>  
>  static inline int _sdma_txadd_daddr(
> @@ -670,13 +670,10 @@ static inline int _sdma_txadd_daddr(
>  	tx->tlen -= len;
>  	/* special cases for last */
>  	if (!tx->tlen) {
> -		if (tx->packet_len & (sizeof(u32) - 1)) {
> +		if (tx->packet_len & (sizeof(u32) - 1))
>  			rval = _pad_sdma_tx_descs(dd, tx);
> -			if (rval)
> -				return rval;
> -		} else {
> +		else
>  			_sdma_close_tx(dd, tx);
> -		}

Same as before, unrelated change.

>  	}
>  	return rval;
>  }
> -- 
> 2.43.0
>
Dennis Dalessandro Jan. 31, 2024, 5:01 p.m. UTC | #2 
On 1/31/24 7:50 AM, Leon Romanovsky wrote:
> On Fri, Jan 26, 2024 at 04:21:23PM +0100, Daniel Vacek wrote:
>> Unfortunately the commit `fd8958efe877` introduced another error
>> causing the `descs` array to overflow. This reults in further crashes
>> easily reproducible by `sendmsg` system call.
>>
>> [ 1080.836473] general protection fault, probably for non-canonical address 0x400300015528b00a: 0000 [#1] PREEMPT SMP PTI
>> [ 1080.869326] RIP: 0010:hfi1_ipoib_build_ib_tx_headers.constprop.0+0xe1/0x2b0 [hfi1]
>> --
>> [ 1080.974535] Call Trace:
>> [ 1080.976990]  <TASK>
>> [ 1081.021929]  hfi1_ipoib_send_dma_common+0x7a/0x2e0 [hfi1]
>> [ 1081.027364]  hfi1_ipoib_send_dma_list+0x62/0x270 [hfi1]
>> [ 1081.032633]  hfi1_ipoib_send+0x112/0x300 [hfi1]
>> [ 1081.042001]  ipoib_start_xmit+0x2a9/0x2d0 [ib_ipoib]
>> [ 1081.046978]  dev_hard_start_xmit+0xc4/0x210
>> --
>> [ 1081.148347]  __sys_sendmsg+0x59/0xa0
>>
>> crash> ipoib_txreq 0xffff9cfeba229f00
>> struct ipoib_txreq {
>>   txreq = {
>>     list = {
>>       next = 0xffff9cfeba229f00,
>>       prev = 0xffff9cfeba229f00
>>     },
>>     descp = 0xffff9cfeba229f40,
>>     coalesce_buf = 0x0,
>>     wait = 0xffff9cfea4e69a48,
>>     complete = 0xffffffffc0fe0760 <hfi1_ipoib_sdma_complete>,
>>     packet_len = 0x46d,
>>     tlen = 0x0,
>>     num_desc = 0x0,
>>     desc_limit = 0x6,
>>     next_descq_idx = 0x45c,
>>     coalesce_idx = 0x0,
>>     flags = 0x0,
>>     descs = {{
>>         qw = {0x8024000120dffb00, 0x4}  # SDMA_DESC0_FIRST_DESC_FLAG (bit 63)
>>       }, {
>>         qw = {  0x3800014231b108, 0x4}
>>       }, {
>>         qw = { 0x310000e4ee0fcf0, 0x8}
>>       }, {
>>         qw = {  0x3000012e9f8000, 0x8}
>>       }, {
>>         qw = {  0x59000dfb9d0000, 0x8}
>>       }, {
>>         qw = {  0x78000e02e40000, 0x8}
>>       }}
>>   },
>>   sdma_hdr =  0x400300015528b000,  <<< invalid pointer in the tx request structure
>>   sdma_status = 0x0,                   SDMA_DESC0_LAST_DESC_FLAG (bit 62)
>>   complete = 0x0,
>>   priv = 0x0,
>>   txq = 0xffff9cfea4e69880,
>>   skb = 0xffff9d099809f400
>> }
>>
>> With this patch the crashes are no longer reproducible and the machine is stable.
>>
>> Note, the header file changes are just an unrelated clean-up while I was looking
>> around trying to find the bug.
>>
>> Fixes: fd8958efe877 ("IB/hfi1: Fix sdma.h tx->num_descs off-by-one errors")
>> Cc: stable@vger.kernel.org
>> Reported-by: Mats Kronberg <kronberg@nsc.liu.se>
>> Tested-by: Mats Kronberg <kronberg@nsc.liu.se>
>> Signed-off-by: Daniel Vacek <neelx@redhat.com>
>> ---
>>  drivers/infiniband/hw/hfi1/sdma.c |  2 +-
>>  drivers/infiniband/hw/hfi1/sdma.h | 17 +++++++----------
>>  2 files changed, 8 insertions(+), 11 deletions(-)
>>
>> diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c
>> index 6e5ac2023328a..b67d23b1f2862 100644
>> --- a/drivers/infiniband/hw/hfi1/sdma.c
>> +++ b/drivers/infiniband/hw/hfi1/sdma.c
>> @@ -3158,7 +3158,7 @@ int _pad_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx)
>>  {
>>  	int rval = 0;
>>  
>> -	if ((unlikely(tx->num_desc + 1 == tx->desc_limit))) {
>> +	if ((unlikely(tx->num_desc == tx->desc_limit))) {
> 
> Maybe, Dennis?

I actually have a patch that does exactly this one line change queued up to send
out.

The commit message for our fix is:
    If an SDMA send consists of exactly 6 descriptors and requires dword
    padding (in the 7th descriptor), the sdma_txreq descriptor array
    is not properly expanded and the packet will overflow into the
    container structure. This results in a panic when the send completion
    runs. The exact panic varies depending on what elements of the
    container structure get corrupted. The fix is to use the correct
    expression in _pad_sdma_tx_descs() to test the need to expand the
    descriptor array.



>>  		rval = _extend_sdma_tx_descs(dd, tx);
>>  		if (rval) {
>>  			__sdma_txclean(dd, tx);
>> diff --git a/drivers/infiniband/hw/hfi1/sdma.h b/drivers/infiniband/hw/hfi1/sdma.h
>> index d77246b48434f..362815a8da267 100644
>> --- a/drivers/infiniband/hw/hfi1/sdma.h
>> +++ b/drivers/infiniband/hw/hfi1/sdma.h
>> @@ -639,13 +639,13 @@ static inline void sdma_txclean(struct hfi1_devdata *dd, struct sdma_txreq *tx)
>>  static inline void _sdma_close_tx(struct hfi1_devdata *dd,
>>  				  struct sdma_txreq *tx)
>>  {
>> -	u16 last_desc = tx->num_desc - 1;
>> +	struct sdma_desc *desc = &tx->descp[tx->num_desc - 1];
>>  
>> -	tx->descp[last_desc].qw[0] |= SDMA_DESC0_LAST_DESC_FLAG;
>> -	tx->descp[last_desc].qw[1] |= dd->default_desc1;
>> +	desc->qw[0] |= SDMA_DESC0_LAST_DESC_FLAG;
>> +	desc->qw[1] |= dd->default_desc1;
>>  	if (tx->flags & SDMA_TXREQ_F_URGENT)
>> -		tx->descp[last_desc].qw[1] |= (SDMA_DESC1_HEAD_TO_HOST_FLAG |
>> -					       SDMA_DESC1_INT_REQ_FLAG);
>> +		desc->qw[1] |= (SDMA_DESC1_HEAD_TO_HOST_FLAG |
>> +				SDMA_DESC1_INT_REQ_FLAG);
> 
> Unrelated change which doesn't change anything.

Please drop.

> 
>>  }
>>  
>>  static inline int _sdma_txadd_daddr(
>> @@ -670,13 +670,10 @@ static inline int _sdma_txadd_daddr(
>>  	tx->tlen -= len;
>>  	/* special cases for last */
>>  	if (!tx->tlen) {
>> -		if (tx->packet_len & (sizeof(u32) - 1)) {
>> +		if (tx->packet_len & (sizeof(u32) - 1))
>>  			rval = _pad_sdma_tx_descs(dd, tx);
>> -			if (rval)
>> -				return rval;
>> -		} else {
>> +		else
>>  			_sdma_close_tx(dd, tx);
>> -		}
> 
> Same as before, unrelated change.

Agree. Please drop.
diff mbox series

Patch

diff --git a/drivers/infiniband/hw/hfi1/sdma.c b/drivers/infiniband/hw/hfi1/sdma.c
index 6e5ac2023328a..b67d23b1f2862 100644
--- a/drivers/infiniband/hw/hfi1/sdma.c
+++ b/drivers/infiniband/hw/hfi1/sdma.c
@@ -3158,7 +3158,7 @@  int _pad_sdma_tx_descs(struct hfi1_devdata *dd, struct sdma_txreq *tx)
 {
 	int rval = 0;
 
-	if ((unlikely(tx->num_desc + 1 == tx->desc_limit))) {
+	if ((unlikely(tx->num_desc == tx->desc_limit))) {
 		rval = _extend_sdma_tx_descs(dd, tx);
 		if (rval) {
 			__sdma_txclean(dd, tx);
diff --git a/drivers/infiniband/hw/hfi1/sdma.h b/drivers/infiniband/hw/hfi1/sdma.h
index d77246b48434f..362815a8da267 100644
--- a/drivers/infiniband/hw/hfi1/sdma.h
+++ b/drivers/infiniband/hw/hfi1/sdma.h
@@ -639,13 +639,13 @@  static inline void sdma_txclean(struct hfi1_devdata *dd, struct sdma_txreq *tx)
 static inline void _sdma_close_tx(struct hfi1_devdata *dd,
 				  struct sdma_txreq *tx)
 {
-	u16 last_desc = tx->num_desc - 1;
+	struct sdma_desc *desc = &tx->descp[tx->num_desc - 1];
 
-	tx->descp[last_desc].qw[0] |= SDMA_DESC0_LAST_DESC_FLAG;
-	tx->descp[last_desc].qw[1] |= dd->default_desc1;
+	desc->qw[0] |= SDMA_DESC0_LAST_DESC_FLAG;
+	desc->qw[1] |= dd->default_desc1;
 	if (tx->flags & SDMA_TXREQ_F_URGENT)
-		tx->descp[last_desc].qw[1] |= (SDMA_DESC1_HEAD_TO_HOST_FLAG |
-					       SDMA_DESC1_INT_REQ_FLAG);
+		desc->qw[1] |= (SDMA_DESC1_HEAD_TO_HOST_FLAG |
+				SDMA_DESC1_INT_REQ_FLAG);
 }
 
 static inline int _sdma_txadd_daddr(
@@ -670,13 +670,10 @@  static inline int _sdma_txadd_daddr(
 	tx->tlen -= len;
 	/* special cases for last */
 	if (!tx->tlen) {
-		if (tx->packet_len & (sizeof(u32) - 1)) {
+		if (tx->packet_len & (sizeof(u32) - 1))
 			rval = _pad_sdma_tx_descs(dd, tx);
-			if (rval)
-				return rval;
-		} else {
+		else
 			_sdma_close_tx(dd, tx);
-		}
 	}
 	return rval;
 }