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* [PATCH] net sched: text ematch: zero out ts_state before using it
@ 2014-10-09 16:05 Omar Sandoval
  2014-10-09 16:28 ` Omar Sandoval
  2014-10-09 21:48 ` Cong Wang
  0 siblings, 2 replies; 4+ messages in thread
From: Omar Sandoval @ 2014-10-09 16:05 UTC (permalink / raw)
  To: Jamal Hadi Salim, David S. Miller, netdev, linux-kernel; +Cc: Omar Sandoval

textsearch_find zeroes out the offset, but the control buffer (which may or may
not matter in this case) needs to be zeroed out as well.

Signed-off-by: Omar Sandoval <osandov@osandov.com>
---
 net/sched/em_text.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/sched/em_text.c b/net/sched/em_text.c
index 15d353d..2a1b6d9 100644
--- a/net/sched/em_text.c
+++ b/net/sched/em_text.c
@@ -36,6 +36,8 @@ static int em_text_match(struct sk_buff *skb, struct tcf_ematch *m,
 	int from, to;
 	struct ts_state state;
 
+	memset(&state, 0, sizeof(state));
+
 	from = tcf_get_base_ptr(skb, tm->from_layer) - skb->data;
 	from += tm->from_offset;
 
-- 
2.1.2

^ permalink raw reply related	[flat|nested] 4+ messages in thread

* Re: [PATCH] net sched: text ematch: zero out ts_state before using it
  2014-10-09 16:05 [PATCH] net sched: text ematch: zero out ts_state before using it Omar Sandoval
@ 2014-10-09 16:28 ` Omar Sandoval
  2014-10-09 21:48 ` Cong Wang
  1 sibling, 0 replies; 4+ messages in thread
From: Omar Sandoval @ 2014-10-09 16:28 UTC (permalink / raw)
  To: Jamal Hadi Salim, David S. Miller, netdev, linux-kernel

On Thu, Oct 09, 2014 at 09:05:21AM -0700, Omar Sandoval wrote:
> textsearch_find zeroes out the offset, but the control buffer (which may or may
> not matter in this case) needs to be zeroed out as well.
> 
> Signed-off-by: Omar Sandoval <osandov@osandov.com>
> ---
>  net/sched/em_text.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/sched/em_text.c b/net/sched/em_text.c
> index 15d353d..2a1b6d9 100644
> --- a/net/sched/em_text.c
> +++ b/net/sched/em_text.c
> @@ -36,6 +36,8 @@ static int em_text_match(struct sk_buff *skb, struct tcf_ematch *m,
>  	int from, to;
>  	struct ts_state state;
>  
> +	memset(&state, 0, sizeof(state));
> +
>  	from = tcf_get_base_ptr(skb, tm->from_layer) - skb->data;
>  	from += tm->from_offset;
>  
> -- 
> 2.1.2
> 

I forgot to mention: this patch is against 3.17.

-- 
Omar

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] net sched: text ematch: zero out ts_state before using it
  2014-10-09 16:05 [PATCH] net sched: text ematch: zero out ts_state before using it Omar Sandoval
  2014-10-09 16:28 ` Omar Sandoval
@ 2014-10-09 21:48 ` Cong Wang
  2014-10-09 21:54   ` Omar Sandoval
  1 sibling, 1 reply; 4+ messages in thread
From: Cong Wang @ 2014-10-09 21:48 UTC (permalink / raw)
  To: Omar Sandoval
  Cc: Jamal Hadi Salim, David S. Miller, netdev,
	linux-kernel@vger.kernel.org

On Thu, Oct 9, 2014 at 9:05 AM, Omar Sandoval <osandov@osandov.com> wrote:
> textsearch_find zeroes out the offset, but the control buffer (which may or may
> not matter in this case) needs to be zeroed out as well.

Why? skb_prepare_seq_read() initializes the cb.

Also, the comment says:

 * @state: uninitialized textsearch state variable

^ permalink raw reply	[flat|nested] 4+ messages in thread

* Re: [PATCH] net sched: text ematch: zero out ts_state before using it
  2014-10-09 21:48 ` Cong Wang
@ 2014-10-09 21:54   ` Omar Sandoval
  0 siblings, 0 replies; 4+ messages in thread
From: Omar Sandoval @ 2014-10-09 21:54 UTC (permalink / raw)
  To: Cong Wang
  Cc: Jamal Hadi Salim, David S. Miller, netdev,
	linux-kernel@vger.kernel.org

On Thu, Oct 09, 2014 at 02:48:54PM -0700, Cong Wang wrote:
> On Thu, Oct 9, 2014 at 9:05 AM, Omar Sandoval <osandov@osandov.com> wrote:
> > textsearch_find zeroes out the offset, but the control buffer (which may or may
> > not matter in this case) needs to be zeroed out as well.
> 
> Why? skb_prepare_seq_read() initializes the cb.
> 
> Also, the comment says:
> 
>  * @state: uninitialized textsearch state variable

Mm, thanks, I missed that. It looks like every other caller of skb_find_text is
doing an unnecessary memset in that case. Disregard this, I guess.
-- 
Omar

^ permalink raw reply	[flat|nested] 4+ messages in thread

end of thread, other threads:[~2014-10-09 21:54 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
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2014-10-09 16:05 [PATCH] net sched: text ematch: zero out ts_state before using it Omar Sandoval
2014-10-09 16:28 ` Omar Sandoval
2014-10-09 21:48 ` Cong Wang
2014-10-09 21:54   ` Omar Sandoval

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