On Fri, 2012-10-12 at 14:13 +0200, Stanislaw Gruszka wrote:
> On Tue, Oct 09, 2012 at 10:14:40AM +0100, Pedro Francisco wrote:
> > So, I'm guessing this means it is related to what you found on iwlwifi
> > (even if I'm on iwlegacy)?
>
> Yes, this seems to be cfg80211 problem. I think crash happen because
> cfg80211 is in disassociate state (i.e. has wdev->current_bss NULL) and
> erroneously mac80211 stays in associate state. So while we unload
> module cfg80211_mlme_down() we do not call ieee80211_deauth().
>
> I think this state mishmash happens because wrong behaviour on
> __cfg80211_mlme_deauth(). Below patch try to correct that.
> Can you check if it prevent a crash? On my environment I can
> not reproduce this problem reliably.
Ugh, yeah, what was I thinking with the code below ... ??
> diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
> index ab78b53..9b99b60 100644
> --- a/include/net/cfg80211.h
> +++ b/include/net/cfg80211.h
> @@ -1218,6 +1218,7 @@ struct cfg80211_deauth_request {
> const u8 *ie;
> size_t ie_len;
> u16 reason_code;
> + bool local_state_change;
> };
>
> /**
> diff --git a/net/mac80211/mlme.c b/net/mac80211/mlme.c
> index e714ed8..e510a33 100644
> --- a/net/mac80211/mlme.c
> +++ b/net/mac80211/mlme.c
> @@ -3549,6 +3549,7 @@ int ieee80211_mgd_deauth(struct ieee80211_sub_if_data *sdata,
> {
> struct ieee80211_if_managed *ifmgd = &sdata->u.mgd;
> u8 frame_buf[IEEE80211_DEAUTH_FRAME_LEN];
> + bool tx = !req->local_state_change;
>
> mutex_lock(&ifmgd->mtx);
>
> @@ -3565,12 +3566,12 @@ int ieee80211_mgd_deauth(struct ieee80211_sub_if_data *sdata,
> if (ifmgd->associated &&
> ether_addr_equal(ifmgd->associated->bssid, req->bssid)) {
> ieee80211_set_disassoc(sdata, IEEE80211_STYPE_DEAUTH,
> - req->reason_code, true, frame_buf);
> + req->reason_code, tx, frame_buf);
> } else {
> drv_mgd_prepare_tx(sdata->local, sdata);
> ieee80211_send_deauth_disassoc(sdata, req->bssid,
> IEEE80211_STYPE_DEAUTH,
> - req->reason_code, true,
> + req->reason_code, tx,
> frame_buf);
> }
>
> diff --git a/net/wireless/mlme.c b/net/wireless/mlme.c
> index 3df195a..4954010 100644
> --- a/net/wireless/mlme.c
> +++ b/net/wireless/mlme.c
> @@ -457,21 +457,11 @@ int __cfg80211_mlme_deauth(struct cfg80211_registered_device *rdev,
> .reason_code = reason,
> .ie = ie,
> .ie_len = ie_len,
> + .local_state_change = local_state_change,
> };
>
> ASSERT_WDEV_LOCK(wdev);
>
> - if (local_state_change) {
> - if (wdev->current_bss &&
> - ether_addr_equal(wdev->current_bss->pub.bssid, bssid)) {
> - cfg80211_unhold_bss(wdev->current_bss);
> - cfg80211_put_bss(&wdev->current_bss->pub);
> - wdev->current_bss = NULL;
> - }
> -
> - return 0;
> - }
> -
This looks fine to me. Probably needs Cc: stable?
Then again, maybe if the deauth request is for a BSS that *isn't* the
current BSS we should "swallow" it in cfg80211? IOW, something like
if (local_state_change && (!wdev->current_bss ||
!ether_addr_equal(...))
return 0;
since neither mac80211 nor cfg80211 track authentication... Doesn't
matter much though.
johannes
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