netdev.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [patch 2/2] tipc: potential divide by zero in tipc_link_recv_fragment()
@ 2013-05-06 18:29 Dan Carpenter
  2013-05-06 18:38 ` Sergei Shtylyov
  0 siblings, 1 reply; 5+ messages in thread
From: Dan Carpenter @ 2013-05-06 18:29 UTC (permalink / raw)
  To: Jon Maloy
  Cc: Allan Stephens, David S. Miller, netdev, tipc-discussion,
	kernel-janitors

The worry here is that fragm_sz could be zero since it comes from
skb->data.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 3a6064b3..de94493 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -2524,14 +2524,16 @@ int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
 		struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
 		u32 msg_sz = msg_size(imsg);
 		u32 fragm_sz = msg_data_sz(fragm);
-		u32 exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
+		u32 exp_fragm_cnt;
 		u32 max =  TIPC_MAX_USER_MSG_SIZE + NAMED_H_SIZE;
+
 		if (msg_type(imsg) == TIPC_MCAST_MSG)
 			max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
-		if (msg_size(imsg) > max) {
+		if (fragm_sz == 0 || msg_size(imsg) > max) {
 			kfree_skb(fbuf);
 			return 0;
 		}
+		exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
 		pbuf = tipc_buf_acquire(msg_size(imsg));
 		if (pbuf != NULL) {
 			pbuf->next = *pending;

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [patch 2/2] tipc: potential divide by zero in tipc_link_recv_fragment()
  2013-05-06 18:29 [patch 2/2] tipc: potential divide by zero in tipc_link_recv_fragment() Dan Carpenter
@ 2013-05-06 18:38 ` Sergei Shtylyov
  2013-05-06 18:49   ` Dan Carpenter
  2013-05-06 19:31   ` [patch 2/2 v2] " Dan Carpenter
  0 siblings, 2 replies; 5+ messages in thread
From: Sergei Shtylyov @ 2013-05-06 18:38 UTC (permalink / raw)
  To: Dan Carpenter
  Cc: Jon Maloy, Allan Stephens, David S. Miller, netdev,
	tipc-discussion, kernel-janitors

Hello.

On 06-05-2013 22:29, Dan Carpenter wrote:

> The worry here is that fragm_sz could be zero since it comes from
> skb->data.

> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

> diff --git a/net/tipc/link.c b/net/tipc/link.c
> index 3a6064b3..de94493 100644
> --- a/net/tipc/link.c
> +++ b/net/tipc/link.c
> @@ -2524,14 +2524,16 @@ int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
>   		struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
>   		u32 msg_sz = msg_size(imsg);
>   		u32 fragm_sz = msg_data_sz(fragm);
> -		u32 exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
> +		u32 exp_fragm_cnt;
>   		u32 max =  TIPC_MAX_USER_MSG_SIZE + NAMED_H_SIZE;
> +
>   		if (msg_type(imsg) == TIPC_MCAST_MSG)
>   			max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
> -		if (msg_size(imsg) > max) {
> +		if (fragm_sz == 0 || msg_size(imsg) > max) {
>   			kfree_skb(fbuf);
>   			return 0;
>   		}
> +		exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);

    Don't you think spaces around / should be added at least for 
consistency with %?

WBR, Sergei

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [patch 2/2] tipc: potential divide by zero in tipc_link_recv_fragment()
  2013-05-06 18:38 ` Sergei Shtylyov
@ 2013-05-06 18:49   ` Dan Carpenter
  2013-05-06 19:31   ` [patch 2/2 v2] " Dan Carpenter
  1 sibling, 0 replies; 5+ messages in thread
From: Dan Carpenter @ 2013-05-06 18:49 UTC (permalink / raw)
  To: Sergei Shtylyov
  Cc: Jon Maloy, Allan Stephens, David S. Miller, netdev,
	tipc-discussion, kernel-janitors

On Mon, May 06, 2013 at 10:38:53PM +0400, Sergei Shtylyov wrote:
> Hello.
> 
> On 06-05-2013 22:29, Dan Carpenter wrote:
> 
> >The worry here is that fragm_sz could be zero since it comes from
> >skb->data.
> 
> >Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> 
> >diff --git a/net/tipc/link.c b/net/tipc/link.c
> >index 3a6064b3..de94493 100644
> >--- a/net/tipc/link.c
> >+++ b/net/tipc/link.c
> >@@ -2524,14 +2524,16 @@ int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
> >  		struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
> >  		u32 msg_sz = msg_size(imsg);
> >  		u32 fragm_sz = msg_data_sz(fragm);
> >-		u32 exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
> >+		u32 exp_fragm_cnt;
> >  		u32 max =  TIPC_MAX_USER_MSG_SIZE + NAMED_H_SIZE;
> >+
> >  		if (msg_type(imsg) == TIPC_MCAST_MSG)
> >  			max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
> >-		if (msg_size(imsg) > max) {
> >+		if (fragm_sz == 0 || msg_size(imsg) > max) {
> >  			kfree_skb(fbuf);
> >  			return 0;
> >  		}
> >+		exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
> 
>    Don't you think spaces around / should be added at least for
> consistency with %?

Yep.  I missed that.  I'll resend.

regards,
dan carpenter

^ permalink raw reply	[flat|nested] 5+ messages in thread

* [patch 2/2 v2] tipc: potential divide by zero in tipc_link_recv_fragment()
  2013-05-06 18:38 ` Sergei Shtylyov
  2013-05-06 18:49   ` Dan Carpenter
@ 2013-05-06 19:31   ` Dan Carpenter
  2013-05-06 20:17     ` David Miller
  1 sibling, 1 reply; 5+ messages in thread
From: Dan Carpenter @ 2013-05-06 19:31 UTC (permalink / raw)
  To: Jon Maloy
  Cc: Allan Stephens, David S. Miller, netdev, tipc-discussion,
	kernel-janitors, Sergei Shtylyov

The worry here is that fragm_sz could be zero since it comes from
skb->data.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
v2: fix a whitespace issue

diff --git a/net/tipc/link.c b/net/tipc/link.c
index 3a6064b3..de94493 100644
--- a/net/tipc/link.c
+++ b/net/tipc/link.c
@@ -2524,14 +2524,16 @@ int tipc_link_recv_fragment(struct sk_buff **pending, struct sk_buff **fb,
 		struct tipc_msg *imsg = (struct tipc_msg *)msg_data(fragm);
 		u32 msg_sz = msg_size(imsg);
 		u32 fragm_sz = msg_data_sz(fragm);
-		u32 exp_fragm_cnt = msg_sz/fragm_sz + !!(msg_sz % fragm_sz);
+		u32 exp_fragm_cnt;
 		u32 max =  TIPC_MAX_USER_MSG_SIZE + NAMED_H_SIZE;
+
 		if (msg_type(imsg) == TIPC_MCAST_MSG)
 			max = TIPC_MAX_USER_MSG_SIZE + MCAST_H_SIZE;
-		if (msg_size(imsg) > max) {
+		if (fragm_sz == 0 || msg_size(imsg) > max) {
 			kfree_skb(fbuf);
 			return 0;
 		}
+		exp_fragm_cnt = msg_sz / fragm_sz + !!(msg_sz % fragm_sz);
 		pbuf = tipc_buf_acquire(msg_size(imsg));
 		if (pbuf != NULL) {
 			pbuf->next = *pending;

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [patch 2/2 v2] tipc: potential divide by zero in tipc_link_recv_fragment()
  2013-05-06 19:31   ` [patch 2/2 v2] " Dan Carpenter
@ 2013-05-06 20:17     ` David Miller
  0 siblings, 0 replies; 5+ messages in thread
From: David Miller @ 2013-05-06 20:17 UTC (permalink / raw)
  To: dan.carpenter
  Cc: jon.maloy, allan.stephens, netdev, tipc-discussion,
	kernel-janitors, sergei.shtylyov

From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Mon, 6 May 2013 22:31:17 +0300

> The worry here is that fragm_sz could be zero since it comes from
> skb->data.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>

Applied.

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2013-05-06 20:17 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2013-05-06 18:29 [patch 2/2] tipc: potential divide by zero in tipc_link_recv_fragment() Dan Carpenter
2013-05-06 18:38 ` Sergei Shtylyov
2013-05-06 18:49   ` Dan Carpenter
2013-05-06 19:31   ` [patch 2/2 v2] " Dan Carpenter
2013-05-06 20:17     ` David Miller

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).