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* [PATCH net,stable] s390/qeth: fix length check in SNMP processing
@ 2018-11-28 15:20 ` Julian Wiedmann
  0 siblings, 0 replies; 3+ messages in thread
From: Julian Wiedmann @ 2018-11-28 15:20 UTC (permalink / raw)
  To: David Miller
  Cc: netdev, linux-s390, Martin Schwidefsky, Heiko Carstens,
	Stefan Raspl, Ursula Braun, Julian Wiedmann

The response for a SNMP request can consist of multiple parts, which
the cmd callback stages into a kernel buffer until all parts have been
received. If the callback detects that the staging buffer provides
insufficient space, it bails out with error.
This processing is buggy for the first part of the response - while it
initially checks for a length of 'data_len', it later copies an
additional amount of 'offsetof(struct qeth_snmp_cmd, data)' bytes.

Fix the calculation of 'data_len' for the first part of the response.
This also nicely cleans up the memcpy code.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 4bce5ae65a55..254065271867 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -4518,8 +4518,8 @@ static int qeth_snmp_command_cb(struct qeth_card *card,
 {
 	struct qeth_ipa_cmd *cmd;
 	struct qeth_arp_query_info *qinfo;
-	struct qeth_snmp_cmd *snmp;
 	unsigned char *data;
+	void *snmp_data;
 	__u16 data_len;
 
 	QETH_CARD_TEXT(card, 3, "snpcmdcb");
@@ -4527,7 +4527,6 @@ static int qeth_snmp_command_cb(struct qeth_card *card,
 	cmd = (struct qeth_ipa_cmd *) sdata;
 	data = (unsigned char *)((char *)cmd - reply->offset);
 	qinfo = (struct qeth_arp_query_info *) reply->param;
-	snmp = &cmd->data.setadapterparms.data.snmp;
 
 	if (cmd->hdr.return_code) {
 		QETH_CARD_TEXT_(card, 4, "scer1%x", cmd->hdr.return_code);
@@ -4540,10 +4539,15 @@ static int qeth_snmp_command_cb(struct qeth_card *card,
 		return 0;
 	}
 	data_len = *((__u16 *)QETH_IPA_PDU_LEN_PDU1(data));
-	if (cmd->data.setadapterparms.hdr.seq_no == 1)
-		data_len -= (__u16)((char *)&snmp->data - (char *)cmd);
-	else
-		data_len -= (__u16)((char *)&snmp->request - (char *)cmd);
+	if (cmd->data.setadapterparms.hdr.seq_no == 1) {
+		snmp_data = &cmd->data.setadapterparms.data.snmp;
+		data_len -= offsetof(struct qeth_ipa_cmd,
+				     data.setadapterparms.data.snmp);
+	} else {
+		snmp_data = &cmd->data.setadapterparms.data.snmp.request;
+		data_len -= offsetof(struct qeth_ipa_cmd,
+				     data.setadapterparms.data.snmp.request);
+	}
 
 	/* check if there is enough room in userspace */
 	if ((qinfo->udata_len - qinfo->udata_offset) < data_len) {
@@ -4556,16 +4560,9 @@ static int qeth_snmp_command_cb(struct qeth_card *card,
 	QETH_CARD_TEXT_(card, 4, "sseqn%i",
 		cmd->data.setadapterparms.hdr.seq_no);
 	/*copy entries to user buffer*/
-	if (cmd->data.setadapterparms.hdr.seq_no == 1) {
-		memcpy(qinfo->udata + qinfo->udata_offset,
-		       (char *)snmp,
-		       data_len + offsetof(struct qeth_snmp_cmd, data));
-		qinfo->udata_offset += offsetof(struct qeth_snmp_cmd, data);
-	} else {
-		memcpy(qinfo->udata + qinfo->udata_offset,
-		       (char *)&snmp->request, data_len);
-	}
+	memcpy(qinfo->udata + qinfo->udata_offset, snmp_data, data_len);
 	qinfo->udata_offset += data_len;
+
 	/* check if all replies received ... */
 		QETH_CARD_TEXT_(card, 4, "srtot%i",
 			       cmd->data.setadapterparms.hdr.used_total);
-- 
2.16.4

^ permalink raw reply related	[flat|nested] 3+ messages in thread
* [PATCH net,stable] s390/qeth: fix length check in SNMP processing
@ 2018-11-28 15:20 ` Julian Wiedmann
  0 siblings, 0 replies; 3+ messages in thread
From: Julian Wiedmann @ 2018-11-28 15:20 UTC (permalink / raw)
  To: David Miller
  Cc: netdev, linux-s390, Martin Schwidefsky, Heiko Carstens,
	Stefan Raspl, Ursula Braun, Julian Wiedmann

The response for a SNMP request can consist of multiple parts, which
the cmd callback stages into a kernel buffer until all parts have been
received. If the callback detects that the staging buffer provides
insufficient space, it bails out with error.
This processing is buggy for the first part of the response - while it
initially checks for a length of 'data_len', it later copies an
additional amount of 'offsetof(struct qeth_snmp_cmd, data)' bytes.

Fix the calculation of 'data_len' for the first part of the response.
This also nicely cleans up the memcpy code.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>
---
 drivers/s390/net/qeth_core_main.c | 27 ++++++++++++---------------
 1 file changed, 12 insertions(+), 15 deletions(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 4bce5ae65a55..254065271867 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -4518,8 +4518,8 @@ static int qeth_snmp_command_cb(struct qeth_card *card,
 {
 	struct qeth_ipa_cmd *cmd;
 	struct qeth_arp_query_info *qinfo;
-	struct qeth_snmp_cmd *snmp;
 	unsigned char *data;
+	void *snmp_data;
 	__u16 data_len;
 
 	QETH_CARD_TEXT(card, 3, "snpcmdcb");
@@ -4527,7 +4527,6 @@ static int qeth_snmp_command_cb(struct qeth_card *card,
 	cmd = (struct qeth_ipa_cmd *) sdata;
 	data = (unsigned char *)((char *)cmd - reply->offset);
 	qinfo = (struct qeth_arp_query_info *) reply->param;
-	snmp = &cmd->data.setadapterparms.data.snmp;
 
 	if (cmd->hdr.return_code) {
 		QETH_CARD_TEXT_(card, 4, "scer1%x", cmd->hdr.return_code);
@@ -4540,10 +4539,15 @@ static int qeth_snmp_command_cb(struct qeth_card *card,
 		return 0;
 	}
 	data_len = *((__u16 *)QETH_IPA_PDU_LEN_PDU1(data));
-	if (cmd->data.setadapterparms.hdr.seq_no == 1)
-		data_len -= (__u16)((char *)&snmp->data - (char *)cmd);
-	else
-		data_len -= (__u16)((char *)&snmp->request - (char *)cmd);
+	if (cmd->data.setadapterparms.hdr.seq_no == 1) {
+		snmp_data = &cmd->data.setadapterparms.data.snmp;
+		data_len -= offsetof(struct qeth_ipa_cmd,
+				     data.setadapterparms.data.snmp);
+	} else {
+		snmp_data = &cmd->data.setadapterparms.data.snmp.request;
+		data_len -= offsetof(struct qeth_ipa_cmd,
+				     data.setadapterparms.data.snmp.request);
+	}
 
 	/* check if there is enough room in userspace */
 	if ((qinfo->udata_len - qinfo->udata_offset) < data_len) {
@@ -4556,16 +4560,9 @@ static int qeth_snmp_command_cb(struct qeth_card *card,
 	QETH_CARD_TEXT_(card, 4, "sseqn%i",
 		cmd->data.setadapterparms.hdr.seq_no);
 	/*copy entries to user buffer*/
-	if (cmd->data.setadapterparms.hdr.seq_no == 1) {
-		memcpy(qinfo->udata + qinfo->udata_offset,
-		       (char *)snmp,
-		       data_len + offsetof(struct qeth_snmp_cmd, data));
-		qinfo->udata_offset += offsetof(struct qeth_snmp_cmd, data);
-	} else {
-		memcpy(qinfo->udata + qinfo->udata_offset,
-		       (char *)&snmp->request, data_len);
-	}
+	memcpy(qinfo->udata + qinfo->udata_offset, snmp_data, data_len);
 	qinfo->udata_offset += data_len;
+
 	/* check if all replies received ... */
 		QETH_CARD_TEXT_(card, 4, "srtot%i",
 			       cmd->data.setadapterparms.hdr.used_total);
-- 
2.16.4

^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH net,stable] s390/qeth: fix length check in SNMP processing
  2018-11-28 15:20 ` Julian Wiedmann
  (?)
@ 2018-11-28 19:17 ` David Miller
  -1 siblings, 0 replies; 3+ messages in thread
From: David Miller @ 2018-11-28 19:17 UTC (permalink / raw)
  To: jwi; +Cc: netdev, linux-s390, schwidefsky, heiko.carstens, raspl, ubraun

From: Julian Wiedmann <jwi@linux.ibm.com>
Date: Wed, 28 Nov 2018 16:20:50 +0100

> The response for a SNMP request can consist of multiple parts, which
> the cmd callback stages into a kernel buffer until all parts have been
> received. If the callback detects that the staging buffer provides
> insufficient space, it bails out with error.
> This processing is buggy for the first part of the response - while it
> initially checks for a length of 'data_len', it later copies an
> additional amount of 'offsetof(struct qeth_snmp_cmd, data)' bytes.
> 
> Fix the calculation of 'data_len' for the first part of the response.
> This also nicely cleans up the memcpy code.
> 
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
> Reviewed-by: Ursula Braun <ubraun@linux.ibm.com>

Applied and queued up for -stable.

^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-11-29  6:20 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2018-11-28 15:20 [PATCH net,stable] s390/qeth: fix length check in SNMP processing Julian Wiedmann
2018-11-28 15:20 ` Julian Wiedmann
2018-11-28 19:17 ` David Miller

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