tid is bounded (above) by the size of default_tid_to_tx_fifo (17 elements), but
the size of priv->stations[].tid[] is MAX_TID_COUNT (9) elements.
Signed-off-by: Roel Kluin <[email protected]>
---
diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
index 85ae7a6..e9441c6 100644
--- a/drivers/net/wireless/iwlwifi/iwl-tx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
@@ -1170,6 +1170,8 @@ int iwl_tx_agg_start(struct iwl_priv *priv, const u8 *ra, u16 tid, u16 *ssn)
IWL_ERR(priv, "Start AGG on invalid station
");
return -ENXIO;
}
+ if (unlikely(tid >= MAX_TID_COUNT))
+ return -EINVAL;
if (priv->stations[sta_id].tid[tid].agg.state != IWL_AGG_OFF) {
IWL_ERR(priv, "Start AGG when state is not IWL_AGG_OFF !
");
On Mon, 2009-07-27 at 01:28 -0700, Winkler, Tomas wrote:
>
> > -----Original Message-----
> > From: Zhu, Yi
> > Sent: Monday, July 27, 2009 4:42 AM
> > To: Roel Kluin; Winkler, Tomas; Chatre, Reinette
> > Cc: [email protected]; [email protected];
> > Andrew Morton
> > Subject: Re: [PATCH] iwlwifi: Read outside array bounds
> >
> > On Sun, 2009-07-26 at 05:34 +0800, Roel Kluin wrote:
> > > tid is bounded (above) by the size of default_tid_to_tx_fifo (17
> > elements), but
> > > the size of priv->stations[].tid[] is MAX_TID_COUNT (9) elements.
> >
> > I think MAX_TID_COUNT should be defined as 16 or 17. Tomas?
> >
>
> In general it's 16. In practice we use only 8.
I think the above statement means that we are mostly using EDCA quality
of service which only uses 8 tids. We do not currently use HCCA (and
thus of course not the hybrid) which would cause more tids to be used.
A closer look at this flow to this function shows:
rs_tl_turn_on_agg
->rs_tl_turn_on_agg_for_tid
-->ieee80211_start_tx_ba_session
--->iwl_mac_ampdu_action
---->iwl_tx_agg_start
>From what I can tell the tid is not modified from rs_tl_turn_on_agg to
iwl_tx_agg_start and rs_tl_turn_on_agg will not call further with a
value of tid larger than 7 due to its checking.
I thus do not see that tid may be equal or larger than MAX_TID_COUNT at
this point of checking. Even so, having this check will not do harm and
will increase safety.
This patch is already merged and that is ok, I just wanted to add this
information to it.
Reinette
> -----Original Message-----
> From: Zhu, Yi
> Sent: Monday, July 27, 2009 4:42 AM
> To: Roel Kluin; Winkler, Tomas; Chatre, Reinette
> Cc: [email protected]; [email protected];
> Andrew Morton
> Subject: Re: [PATCH] iwlwifi: Read outside array bounds
>
> On Sun, 2009-07-26 at 05:34 +0800, Roel Kluin wrote:
> > tid is bounded (above) by the size of default_tid_to_tx_fifo (17
> elements), but
> > the size of priv->stations[].tid[] is MAX_TID_COUNT (9) elements.
>
> I think MAX_TID_COUNT should be defined as 16 or 17. Tomas?
>
In general it's 16. In practice we use only 8.
Tomas
> Thanks,
> -yi
>
> > Signed-off-by: Roel Kluin <[email protected]>
> > ---
> > diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c
> b/drivers/net/wireless/iwlwifi/iwl-tx.c
> > index 85ae7a6..e9441c6 100644
> > --- a/drivers/net/wireless/iwlwifi/iwl-tx.c
> > +++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
> > @@ -1170,6 +1170,8 @@ int iwl_tx_agg_start(struct iwl_priv *priv,
> const u8 *ra, u16 tid, u16 *ssn)
> > IWL_ERR(priv, "Start AGG on invalid station
> > ");
> > return -ENXIO;
> > }
> > + if (unlikely(tid >= MAX_TID_COUNT))
> > + return -EINVAL;
> >
> > if (priv->stations[sta_id].tid[tid].agg.state != IWL_AGG_OFF) {
> > IWL_ERR(priv, "Start AGG when state is not IWL_AGG_OFF !
> > ");
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On Sun, 2009-07-26 at 05:34 +0800, Roel Kluin wrote:
> tid is bounded (above) by the size of default_tid_to_tx_fifo (17 elements), but
> the size of priv->stations[].tid[] is MAX_TID_COUNT (9) elements.
I think MAX_TID_COUNT should be defined as 16 or 17. Tomas?
Thanks,
-yi
> Signed-off-by: Roel Kluin <[email protected]>
> ---
> diff --git a/drivers/net/wireless/iwlwifi/iwl-tx.c b/drivers/net/wireless/iwlwifi/iwl-tx.c
> index 85ae7a6..e9441c6 100644
> --- a/drivers/net/wireless/iwlwifi/iwl-tx.c
> +++ b/drivers/net/wireless/iwlwifi/iwl-tx.c
> @@ -1170,6 +1170,8 @@ int iwl_tx_agg_start(struct iwl_priv *priv, const u8 *ra, u16 tid, u16 *ssn)
> IWL_ERR(priv, "Start AGG on invalid station
> ");
> return -ENXIO;
> }
> + if (unlikely(tid >= MAX_TID_COUNT))
> + return -EINVAL;
>
> if (priv->stations[sta_id].tid[tid].agg.state != IWL_AGG_OFF) {
> IWL_ERR(priv, "Start AGG when state is not IWL_AGG_OFF !
> ");
On Tue, 2009-07-28 at 12:50 +0800, Chatre, Reinette wrote:
> On Mon, 2009-07-27 at 19:27 -0700, Zhu, Yi wrote:
> > On Tue, 2009-07-28 at 06:12 +0800, Chatre, Reinette wrote:
> > > On Mon, 2009-07-27 at 01:28 -0700, Winkler, Tomas wrote:
> > > >
> > > > > -----Original Message-----
> > > > > From: Zhu, Yi
> > > > > Sent: Monday, July 27, 2009 4:42 AM
> > > > > To: Roel Kluin; Winkler, Tomas; Chatre, Reinette
> > > > > Cc: [email protected]; [email protected];
> > > > > Andrew Morton
> > > > > Subject: Re: [PATCH] iwlwifi: Read outside array bounds
> > > > >
> > > > > On Sun, 2009-07-26 at 05:34 +0800, Roel Kluin wrote:
> > > > > > tid is bounded (above) by the size of default_tid_to_tx_fifo (17
> > > > > elements), but
> > > > > > the size of priv->stations[].tid[] is MAX_TID_COUNT (9) elements.
> > > > >
> > > > > I think MAX_TID_COUNT should be defined as 16 or 17. Tomas?
> > > > >
> > > >
> > > > In general it's 16. In practice we use only 8.
> > >
> > > I think the above statement means that we are mostly using EDCA quality
> > > of service which only uses 8 tids. We do not currently use HCCA (and
> > > thus of course not the hybrid) which would cause more tids to be used.
> > >
> > > A closer look at this flow to this function shows:
> > > rs_tl_turn_on_agg
> >
> > rs_tl_add_packet
> > {
> > ...
> > u8 *qc = ieee80211_get_qos_ctl(hdr);
> > tid = qc[0] & 0xf;
> > ...
> >
> > tl = &lq_data->load[tid];
> > }
> >
> > This should be a problem.
>
> Indeed. Are there any other cases like this that you can think of? It
> seems like we need Roel's fix for iwl_tx_agg_stop also.
Yes. I think we can do an audit for all the ieee80211_ops callbacks with
tid as a parameter. Because mac80211 use u16 for tid, but iwlwifi use u8
internally.
Thanks,
-yi
On Mon, 2009-07-27 at 19:27 -0700, Zhu, Yi wrote:
> On Tue, 2009-07-28 at 06:12 +0800, Chatre, Reinette wrote:
> > On Mon, 2009-07-27 at 01:28 -0700, Winkler, Tomas wrote:
> > >
> > > > -----Original Message-----
> > > > From: Zhu, Yi
> > > > Sent: Monday, July 27, 2009 4:42 AM
> > > > To: Roel Kluin; Winkler, Tomas; Chatre, Reinette
> > > > Cc: [email protected]; [email protected];
> > > > Andrew Morton
> > > > Subject: Re: [PATCH] iwlwifi: Read outside array bounds
> > > >
> > > > On Sun, 2009-07-26 at 05:34 +0800, Roel Kluin wrote:
> > > > > tid is bounded (above) by the size of default_tid_to_tx_fifo (17
> > > > elements), but
> > > > > the size of priv->stations[].tid[] is MAX_TID_COUNT (9) elements.
> > > >
> > > > I think MAX_TID_COUNT should be defined as 16 or 17. Tomas?
> > > >
> > >
> > > In general it's 16. In practice we use only 8.
> >
> > I think the above statement means that we are mostly using EDCA quality
> > of service which only uses 8 tids. We do not currently use HCCA (and
> > thus of course not the hybrid) which would cause more tids to be used.
> >
> > A closer look at this flow to this function shows:
> > rs_tl_turn_on_agg
>
> rs_tl_add_packet
> {
> ...
> u8 *qc = ieee80211_get_qos_ctl(hdr);
> tid = qc[0] & 0xf;
> ...
>
> tl = &lq_data->load[tid];
> }
>
> This should be a problem.
Indeed. Are there any other cases like this that you can think of? It
seems like we need Roel's fix for iwl_tx_agg_stop also.
Reinette
On Tue, 2009-07-28 at 06:12 +0800, Chatre, Reinette wrote:
> On Mon, 2009-07-27 at 01:28 -0700, Winkler, Tomas wrote:
> >
> > > -----Original Message-----
> > > From: Zhu, Yi
> > > Sent: Monday, July 27, 2009 4:42 AM
> > > To: Roel Kluin; Winkler, Tomas; Chatre, Reinette
> > > Cc: [email protected]; [email protected];
> > > Andrew Morton
> > > Subject: Re: [PATCH] iwlwifi: Read outside array bounds
> > >
> > > On Sun, 2009-07-26 at 05:34 +0800, Roel Kluin wrote:
> > > > tid is bounded (above) by the size of default_tid_to_tx_fifo (17
> > > elements), but
> > > > the size of priv->stations[].tid[] is MAX_TID_COUNT (9) elements.
> > >
> > > I think MAX_TID_COUNT should be defined as 16 or 17. Tomas?
> > >
> >
> > In general it's 16. In practice we use only 8.
>
> I think the above statement means that we are mostly using EDCA quality
> of service which only uses 8 tids. We do not currently use HCCA (and
> thus of course not the hybrid) which would cause more tids to be used.
>
> A closer look at this flow to this function shows:
> rs_tl_turn_on_agg
rs_tl_add_packet
{
...
u8 *qc = ieee80211_get_qos_ctl(hdr);
tid = qc[0] & 0xf;
...
tl = &lq_data->load[tid];
}
This should be a problem.
Thanks,
-yi