Add support to indicate maximum number of AKMs allowed in
NL80211_CMD_CONNECT, NL80211_CMD_ASSOCIATE and NL80211_CMD_START_AP.
If the driver doesn't indicate the capability, maximum limit is set to
the legacy value i.e. NL80211_MAX_NR_AKM_SUITE.
Contains a fix for the issue:
Reported-by: kernel test robot <[email protected]>
Signed-off-by: Veerendranath Jakkam <[email protected]>
---
v2:
Fixed issue reported by kernel test robot.
---
drivers/net/wireless/ath/wil6210/cfg80211.c | 3 +--
drivers/net/wireless/quantenna/qtnfmac/commands.c | 6 ++++--
include/net/cfg80211.h | 6 +++++-
include/uapi/linux/nl80211.h | 15 +++++++++++++++
net/wireless/core.c | 11 +++++++++++
net/wireless/nl80211.c | 15 +++++++++++++--
net/wireless/sme.c | 20 +++++++++++++++++++-
net/wireless/wext-compat.c | 8 ++++++++
8 files changed, 76 insertions(+), 8 deletions(-)
diff --git a/drivers/net/wireless/ath/wil6210/cfg80211.c b/drivers/net/wireless/ath/wil6210/cfg80211.c
index 764d1d1..ac40fe2 100644
--- a/drivers/net/wireless/ath/wil6210/cfg80211.c
+++ b/drivers/net/wireless/ath/wil6210/cfg80211.c
@@ -1073,8 +1073,7 @@ static void wil_print_crypto(struct wil6210_priv *wil,
c->ciphers_pairwise[i]);
wil_dbg_misc(wil, "}\n");
wil_dbg_misc(wil, "AKM suites [%d] {\n", c->n_akm_suites);
- n = min_t(int, c->n_akm_suites, ARRAY_SIZE(c->akm_suites));
- for (i = 0; i < n; i++)
+ for (i = 0; i < c->n_akm_suites; i++)
wil_dbg_misc(wil, " [%d] = 0x%08x\n", i,
c->akm_suites[i]);
wil_dbg_misc(wil, "}\n");
diff --git a/drivers/net/wireless/quantenna/qtnfmac/commands.c b/drivers/net/wireless/quantenna/qtnfmac/commands.c
index c68563c..ace78ff 100644
--- a/drivers/net/wireless/quantenna/qtnfmac/commands.c
+++ b/drivers/net/wireless/quantenna/qtnfmac/commands.c
@@ -281,7 +281,8 @@ int qtnf_cmd_send_start_ap(struct qtnf_vif *vif,
aen->ciphers_pairwise[i] =
cpu_to_le32(s->crypto.ciphers_pairwise[i]);
aen->n_akm_suites = cpu_to_le32(s->crypto.n_akm_suites);
- for (i = 0; i < QLINK_MAX_NR_AKM_SUITES; i++)
+ for (i = 0; i < min(QLINK_MAX_NR_AKM_SUITES, s->crypto.n_akm_suites);
+ i++)
aen->akm_suites[i] = cpu_to_le32(s->crypto.akm_suites[i]);
aen->control_port = s->crypto.control_port;
aen->control_port_no_encrypt = s->crypto.control_port_no_encrypt;
@@ -2134,7 +2135,8 @@ int qtnf_cmd_send_connect(struct qtnf_vif *vif,
aen->n_akm_suites = cpu_to_le32(sme->crypto.n_akm_suites);
- for (i = 0; i < QLINK_MAX_NR_AKM_SUITES; i++)
+ for (i = 0; i < min(QLINK_MAX_NR_AKM_SUITES, sme->crypto.n_akm_suites);
+ i++)
aen->akm_suites[i] = cpu_to_le32(sme->crypto.akm_suites[i]);
aen->control_port = sme->crypto.control_port;
diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 6871338..48c7ab1 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1112,7 +1112,7 @@ struct cfg80211_crypto_settings {
int n_ciphers_pairwise;
u32 ciphers_pairwise[NL80211_MAX_NR_CIPHER_SUITES];
int n_akm_suites;
- u32 akm_suites[NL80211_MAX_NR_AKM_SUITES];
+ u32 *akm_suites;
bool control_port;
__be16 control_port_ethertype;
bool control_port_no_encrypt;
@@ -5129,6 +5129,9 @@ struct wiphy_iftype_akm_suites {
* @ema_max_profile_periodicity: maximum profile periodicity supported by
* the driver. Setting this field to a non-zero value indicates that the
* driver supports enhanced multi-BSSID advertisements (EMA AP).
+ * @max_num_akm_suites: maximum supported number of AKM suites for
+ * configuration through %NL80211_CMD_CONNECT, %NL80211_CMD_ASSOCIATE and
+ * %NL80211_CMD_START_AP.
*/
struct wiphy {
struct mutex mtx;
@@ -5275,6 +5278,7 @@ struct wiphy {
u8 mbssid_max_interfaces;
u8 ema_max_profile_periodicity;
+ u16 max_num_akm_suites;
char priv[] __aligned(NETDEV_ALIGN);
};
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 0568a79..00fa5ea 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -2663,6 +2663,13 @@ enum nl80211_commands {
* association request when used with NL80211_CMD_NEW_STATION). Can be set
* only if %NL80211_STA_FLAG_WME is set.
*
+ * @NL80211_ATTR_MAX_NUM_AKM_SUITES: U16 attribute. Indicates maximum number of
+ * AKM suites allowed for %NL80211_CMD_CONNECT, %NL80211_CMD_ASSOCIATE and
+ * %NL80211_CMD_START_AP. If this attribute is not present userspace shall
+ * consider maximum number of AKM suites supported as
+ * %NL80211_MAX_NR_AKM_SUITES which is the legacy maximum number prior to
+ * the introduction of this attribute.
+ *
* @NUM_NL80211_ATTR: total number of nl80211_attrs available
* @NL80211_ATTR_MAX: highest attribute number currently defined
* @__NL80211_ATTR_AFTER_LAST: internal use
@@ -3175,6 +3182,8 @@ enum nl80211_attrs {
NL80211_ATTR_EHT_CAPABILITY,
+ NL80211_ATTR_MAX_NUM_AKM_SUITES,
+
/* add attributes here, update the policy in nl80211.c */
__NL80211_ATTR_AFTER_LAST,
@@ -3229,6 +3238,12 @@ enum nl80211_attrs {
#define NL80211_HE_MIN_CAPABILITY_LEN 16
#define NL80211_HE_MAX_CAPABILITY_LEN 54
#define NL80211_MAX_NR_CIPHER_SUITES 5
+
+/*
+ * NL80211_MAX_NR_AKM_SUITES is obsolete and not used for indicating maximum
+ * number of supported AKM suites. Instead, maximum number of supported AKM
+ * suites is indicated using %NL80211_ATTR_MAX_NUM_AKM_SUITES attribute.
+ */
#define NL80211_MAX_NR_AKM_SUITES 2
#define NL80211_EHT_MIN_CAPABILITY_LEN 13
#define NL80211_EHT_MAX_CAPABILITY_LEN 51
diff --git a/net/wireless/core.c b/net/wireless/core.c
index f08d4b3..282cabc 100644
--- a/net/wireless/core.c
+++ b/net/wireless/core.c
@@ -913,6 +913,15 @@ int wiphy_register(struct wiphy *wiphy)
return -EINVAL;
#endif
+ /*
+ * Maximum number of AKM suites allowed for NL80211_CMD_CONECT,
+ * NL80211_CMD_ASSOCIATE and NL80211_CMD_START_AP, must be at least
+ * NL80211_MAX_NR_AKM_SUITES to avoid issues with legacy userspace.
+ */
+ if (WARN_ON(wiphy->max_num_akm_suites &&
+ wiphy->max_num_akm_suites < NL80211_MAX_NR_AKM_SUITES))
+ return -EINVAL;
+
/* check and set up bitrates */
ieee80211_set_bitrate_flags(wiphy);
@@ -1154,6 +1163,8 @@ static void _cfg80211_unregister_wdev(struct wireless_dev *wdev,
#ifdef CONFIG_CFG80211_WEXT
kfree_sensitive(wdev->wext.keys);
wdev->wext.keys = NULL;
+ kfree(wdev->wext.connect.crypto.akm_suites);
+ wdev->wext.connect.crypto.akm_suites = NULL;
#endif
/* only initialized if we have a netdev */
if (wdev->netdev)
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 711061c..4b7cbd5 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -790,6 +790,7 @@ static const struct nla_policy nl80211_policy[NUM_NL80211_ATTR] = {
NLA_POLICY_RANGE(NLA_BINARY,
NL80211_EHT_MIN_CAPABILITY_LEN,
NL80211_EHT_MAX_CAPABILITY_LEN),
+ [NL80211_ATTR_MAX_NUM_AKM_SUITES] = { .type = NLA_U16 },
};
/* policy for the key attributes */
@@ -2889,6 +2890,12 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev,
if (nl80211_put_mbssid_support(&rdev->wiphy, msg))
goto nla_put_failure;
+ if (nla_put_u16(msg, NL80211_ATTR_MAX_NUM_AKM_SUITES,
+ rdev->wiphy.max_num_akm_suites ?
+ rdev->wiphy.max_num_akm_suites :
+ NL80211_MAX_NR_AKM_SUITES))
+ goto nla_put_failure;
+
/* done */
state->split_start = 0;
break;
@@ -10253,6 +10260,7 @@ static int nl80211_crypto_settings(struct cfg80211_registered_device *rdev,
if (info->attrs[NL80211_ATTR_AKM_SUITES]) {
void *data;
int len;
+ int max_num_akm_suites = NL80211_MAX_NR_AKM_SUITES;
data = nla_data(info->attrs[NL80211_ATTR_AKM_SUITES]);
len = nla_len(info->attrs[NL80211_ATTR_AKM_SUITES]);
@@ -10261,10 +10269,13 @@ static int nl80211_crypto_settings(struct cfg80211_registered_device *rdev,
if (len % sizeof(u32))
return -EINVAL;
- if (settings->n_akm_suites > NL80211_MAX_NR_AKM_SUITES)
+ if (rdev->wiphy.max_num_akm_suites)
+ max_num_akm_suites = rdev->wiphy.max_num_akm_suites;
+
+ if (settings->n_akm_suites > max_num_akm_suites)
return -EINVAL;
- memcpy(settings->akm_suites, data, len);
+ settings->akm_suites = data;
}
if (info->attrs[NL80211_ATTR_PMK]) {
diff --git a/net/wireless/sme.c b/net/wireless/sme.c
index ff4d48fc..1ff9513 100644
--- a/net/wireless/sme.c
+++ b/net/wireless/sme.c
@@ -57,6 +57,7 @@ static void cfg80211_sme_free(struct wireless_dev *wdev)
return;
kfree(wdev->conn->ie);
+ kfree(wdev->conn->params.crypto.akm_suites);
kfree(wdev->conn);
wdev->conn = NULL;
}
@@ -537,7 +538,8 @@ static int cfg80211_sme_connect(struct wireless_dev *wdev,
return -ENOMEM;
/*
- * Copy all parameters, and treat explicitly IEs, BSSID, SSID.
+ * Copy all parameters, and treat explicitly IEs, BSSID, SSID,
+ * AKM SUITES.
*/
memcpy(&wdev->conn->params, connect, sizeof(*connect));
if (connect->bssid) {
@@ -563,6 +565,22 @@ static int cfg80211_sme_connect(struct wireless_dev *wdev,
wdev->conn->auto_auth = false;
}
+ if (connect->crypto.n_akm_suites) {
+ wdev->conn->params.crypto.akm_suites =
+ kcalloc(connect->crypto.n_akm_suites, sizeof(u32),
+ GFP_KERNEL);
+ if (!wdev->conn->params.crypto.akm_suites) {
+ cfg80211_sme_free(wdev);
+ return -ENOMEM;
+ }
+
+ wdev->conn->params.crypto.n_akm_suites =
+ connect->crypto.n_akm_suites;
+ memcpy(wdev->conn->params.crypto.akm_suites,
+ connect->crypto.akm_suites,
+ sizeof(u32) * connect->crypto.n_akm_suites);
+ }
+
wdev->conn->params.ssid = wdev->ssid;
wdev->conn->params.ssid_len = wdev->ssid_len;
diff --git a/net/wireless/wext-compat.c b/net/wireless/wext-compat.c
index a32065d..0d262e9 100644
--- a/net/wireless/wext-compat.c
+++ b/net/wireless/wext-compat.c
@@ -1102,6 +1102,14 @@ static int cfg80211_set_key_mgt(struct wireless_dev *wdev, u32 key_mgt)
IW_AUTH_KEY_MGMT_PSK))
return -EINVAL;
+ if (!wdev->wext.connect.crypto.akm_suites) {
+ wdev->wext.connect.crypto.akm_suites =
+ kcalloc(NL80211_MAX_NR_AKM_SUITES, sizeof(u32),
+ GFP_KERNEL);
+ if (!wdev->wext.connect.crypto.akm_suites)
+ return -ENOMEM;
+ }
+
if (key_mgt & IW_AUTH_KEY_MGMT_802_1X) {
wdev->wext.connect.crypto.akm_suites[nr_akm_suites] =
WLAN_AKM_SUITE_8021X;
--
2.7.4
I don't know why, but this patch seems to cause memory corruption and
various issues when I run the hwsim tests.
I did make a few minor changes, but I think those were OK.
> --- a/include/net/cfg80211.h
> +++ b/include/net/cfg80211.h
> @@ -1112,7 +1112,7 @@ struct cfg80211_crypto_settings {
> int n_ciphers_pairwise;
> u32 ciphers_pairwise[NL80211_MAX_NR_CIPHER_SUITES];
> int n_akm_suites;
> - u32 akm_suites[NL80211_MAX_NR_AKM_SUITES];
> + u32 *akm_suites;
I made this const, that required a bit of juggling in the wext code, but
it's probably still better overall.
>
> + /*
> + * Maximum number of AKM suites allowed for NL80211_CMD_CONECT,
> + * NL80211_CMD_ASSOCIATE and NL80211_CMD_START_AP, must be at least
> + * NL80211_MAX_NR_AKM_SUITES to avoid issues with legacy userspace.
> + */
> + if (WARN_ON(wiphy->max_num_akm_suites &&
> + wiphy->max_num_akm_suites < NL80211_MAX_NR_AKM_SUITES))
> + return -EINVAL;
I made it so here if it's 0 we set it to NL80211_MAX_NR_AKM_SUITES, that
way we don't need to have all the questions about it being 0 later.
> + if (nla_put_u16(msg, NL80211_ATTR_MAX_NUM_AKM_SUITES,
> + rdev->wiphy.max_num_akm_suites ?
> + rdev->wiphy.max_num_akm_suites :
> + NL80211_MAX_NR_AKM_SUITES))
> + goto nla_put_failure;
e.g. here, that was then without the ternary operator
> + int max_num_akm_suites = NL80211_MAX_NR_AKM_SUITES;
>
> data = nla_data(info->attrs[NL80211_ATTR_AKM_SUITES]);
> len = nla_len(info->attrs[NL80211_ATTR_AKM_SUITES]);
> @@ -10261,10 +10269,13 @@ static int nl80211_crypto_settings(struct cfg80211_registered_device *rdev,
> if (len % sizeof(u32))
> return -EINVAL;
>
> - if (settings->n_akm_suites > NL80211_MAX_NR_AKM_SUITES)
> + if (rdev->wiphy.max_num_akm_suites)
> + max_num_akm_suites = rdev->wiphy.max_num_akm_suites;
> +
> + if (settings->n_akm_suites > max_num_akm_suites)
> return -EINVAL;
>
> - memcpy(settings->akm_suites, data, len);
> + settings->akm_suites = data;
and all that complexity also goes away
> + if (connect->crypto.n_akm_suites) {
> + wdev->conn->params.crypto.akm_suites =
> + kcalloc(connect->crypto.n_akm_suites, sizeof(u32),
> + GFP_KERNEL);
> + if (!wdev->conn->params.crypto.akm_suites) {
> + cfg80211_sme_free(wdev);
> + return -ENOMEM;
> + }
> +
> + wdev->conn->params.crypto.n_akm_suites =
> + connect->crypto.n_akm_suites;
> + memcpy(wdev->conn->params.crypto.akm_suites,
> + connect->crypto.akm_suites,
> + sizeof(u32) * connect->crypto.n_akm_suites);
I made this use kmemdup(), I don't think it makes a big difference.
Anyway, it crashes. Perhaps an invalid free, because the middle of some
netlink packet is being freed or so?
Please check.
johannes
On 5/5/2022 2:24 AM, Johannes Berg wrote:
> I don't know why, but this patch seems to cause memory corruption and
> various issues when I run the hwsim tests.
>
Oh.. I ran some hwsim tests from hostap.git to verify the changes but
didn't face any issues. Are you seeing the issues with any specific
hwsim tests? Also, the issues are coming without any of the below
changes also(i.e. with actual patch i sent)?
> I did make a few minor changes, but I think those were OK.
>
>
>> --- a/include/net/cfg80211.h
>> +++ b/include/net/cfg80211.h
>> @@ -1112,7 +1112,7 @@ struct cfg80211_crypto_settings {
>> int n_ciphers_pairwise;
>> u32 ciphers_pairwise[NL80211_MAX_NR_CIPHER_SUITES];
>> int n_akm_suites;
>> - u32 akm_suites[NL80211_MAX_NR_AKM_SUITES];
>> + u32 *akm_suites;
>
> I made this const, that required a bit of juggling in the wext code, but
> it's probably still better overall.
>
>>
>> + /*
>> + * Maximum number of AKM suites allowed for NL80211_CMD_CONECT,
>> + * NL80211_CMD_ASSOCIATE and NL80211_CMD_START_AP, must be at least
>> + * NL80211_MAX_NR_AKM_SUITES to avoid issues with legacy userspace.
>> + */
>> + if (WARN_ON(wiphy->max_num_akm_suites &&
>> + wiphy->max_num_akm_suites < NL80211_MAX_NR_AKM_SUITES))
>> + return -EINVAL;
>
> I made it so here if it's 0 we set it to NL80211_MAX_NR_AKM_SUITES, that
> way we don't need to have all the questions about it being 0 later.
>
>> + if (nla_put_u16(msg, NL80211_ATTR_MAX_NUM_AKM_SUITES,
>> + rdev->wiphy.max_num_akm_suites ?
>> + rdev->wiphy.max_num_akm_suites :
>> + NL80211_MAX_NR_AKM_SUITES))
>> + goto nla_put_failure;
>
> e.g. here, that was then without the ternary operator
>
>> + int max_num_akm_suites = NL80211_MAX_NR_AKM_SUITES;
>>
>> data = nla_data(info->attrs[NL80211_ATTR_AKM_SUITES]);
>> len = nla_len(info->attrs[NL80211_ATTR_AKM_SUITES]);
>> @@ -10261,10 +10269,13 @@ static int nl80211_crypto_settings(struct cfg80211_registered_device *rdev,
>> if (len % sizeof(u32))
>> return -EINVAL;
>>
>> - if (settings->n_akm_suites > NL80211_MAX_NR_AKM_SUITES)
>> + if (rdev->wiphy.max_num_akm_suites)
>> + max_num_akm_suites = rdev->wiphy.max_num_akm_suites;
>> +
>> + if (settings->n_akm_suites > max_num_akm_suites)
>> return -EINVAL;
>>
>> - memcpy(settings->akm_suites, data, len);
>> + settings->akm_suites = data;
>
> and all that complexity also goes away
>
>> + if (connect->crypto.n_akm_suites) {
>> + wdev->conn->params.crypto.akm_suites =
>> + kcalloc(connect->crypto.n_akm_suites, sizeof(u32),
>> + GFP_KERNEL);
>> + if (!wdev->conn->params.crypto.akm_suites) {
>> + cfg80211_sme_free(wdev);
>> + return -ENOMEM;
>> + }
>> +
>> + wdev->conn->params.crypto.n_akm_suites =
>> + connect->crypto.n_akm_suites;
>> + memcpy(wdev->conn->params.crypto.akm_suites,
>> + connect->crypto.akm_suites,
>> + sizeof(u32) * connect->crypto.n_akm_suites);
>
> I made this use kmemdup(), I don't think it makes a big difference.
>
> Anyway, it crashes. Perhaps an invalid free, because the middle of some
> netlink packet is being freed or so? >
> Please check.
Sure, I will try with suggested changes and update you
>
> johannes
--
veeru
On Thu, 2022-05-05 at 10:40 +0530, Veerendranath Jakkam wrote:
>
> On 5/5/2022 2:24 AM, Johannes Berg wrote:
> > I don't know why, but this patch seems to cause memory corruption and
> > various issues when I run the hwsim tests.
> >
> Oh.. I ran some hwsim tests from hostap.git to verify the changes but
> didn't face any issues. Are you seeing the issues with any specific
> hwsim tests? Also, the issues are coming without any of the below
> changes also(i.e. with actual patch i sent)?
Yes.
I also came to think - where's the upstream driver using this?
I've been saying this for something like a decade now, I think I'll stop
investing time in such patches.
johannes
On Thu, May 05, 2022 at 09:18:40AM +0200, Johannes Berg wrote:
> I also came to think - where's the upstream driver using this?
This capability is needed to implement WPA3-Personal transition mode
correctly with any driver that handles roaming internally, i.e., that
advertises NL80211_ATTR_ROAM_SUPPORT (WIPHY_FLAG_SUPPORTS_FW_ROAM). It
looks like there are two such drivers in the upstream tree today: ath6kl
and brcmfmac. Since WPA3 requires PMF, ath6kl is not really a candidate
for the main use for this (having to indicate PSK, PSK-SHA-256, and SAE
AKMs as allowed), but brcmfmac looks like an example that would need
this to allow the local network profile parameters to be set
appropriately to the driver to allow all the desired roaming cases
between BSSs using different AKM suite selectors to be performed.
That said, I do not know whether someone would be planning on using this
additional capability to extend brcmfmac to take benefit of the proposed
extension. I would support this capability in wpa_supplicant, though, so
the information would be available for that purpose.
> I've been saying this for something like a decade now, I think I'll stop
> investing time in such patches.
Do you have any preference on how to address out-of-the-tree driver
needs for this type of functionality? Many cases today can be covered
through the use of vendor specific commands and events, but there are
some inconvenient examples like the Connect command that is not really
straightforward to replace or extend with vendor commands due to the
concept of tracking the user space process associated with the
connection and internal cfg80211 tracking of the connection in general.
If additional nl80211 attributes cannot be accepted into the upstream
tree for such specific needs, could there be some way of allowing
vendor specific attributes to be added into the Connect command? Or
would this need to use some kind of ugly combination of a vendor
specific command first to modify the behavior of the following Connect
command to address this type of needs?
--
Jouni Malinen PGP id EFC895FA
On Thu, 2022-05-05 at 21:19 +0300, Jouni Malinen wrote:
> On Thu, May 05, 2022 at 09:18:40AM +0200, Johannes Berg wrote:
> > I also came to think - where's the upstream driver using this?
>
> This capability is needed to implement WPA3-Personal transition mode
> correctly with any driver that handles roaming internally, i.e., that
> advertises NL80211_ATTR_ROAM_SUPPORT (WIPHY_FLAG_SUPPORTS_FW_ROAM). It
> looks like there are two such drivers in the upstream tree today: ath6kl
> and brcmfmac. Since WPA3 requires PMF, ath6kl is not really a candidate
> for the main use for this (having to indicate PSK, PSK-SHA-256, and SAE
> AKMs as allowed), but brcmfmac looks like an example that would need
> this to allow the local network profile parameters to be set
> appropriately to the driver to allow all the desired roaming cases
> between BSSs using different AKM suite selectors to be performed.
Makes sense.
> That said, I do not know whether someone would be planning on using this
> additional capability to extend brcmfmac to take benefit of the proposed
> extension. I would support this capability in wpa_supplicant, though, so
> the information would be available for that purpose.
:)
Honestly for this patch, I'd drop the dynamic allocation parts that are
problematic - assuming we can limit to something else that's sensible
like 4 or 5 entries?
> Do you have any preference on how to address out-of-the-tree driver
> needs for this type of functionality?
>
I don't - I'm just noting we keep having this discussion. And I'm just
grumpy because all my tests failed on this, probably with a kfree() of a
stray pointer or so :)
Upstream the driver? ;-)
johannes