diff options
| author |   Johannes Berg <johannes@sipsolutions.net> | 2007-09-26 15:19:47 +0200 |
|---|---|---|
| committer |   David S. Miller <davem@sunset.davemloft.net> | 2007-10-10 16:53:16 -0700 |
| commit | 53918994b7c8c3bf0af5f641e1f299856799d883 (patch) | |
| tree | 63338872613d3c08473acfb46c8a57490f85350b /net/mac80211/ieee80211.c | |
| parent | [PATCH] mac80211: fix TKIP IV update (diff) | |
| download | linux-dev-53918994b7c8c3bf0af5f641e1f299856799d883.tar.xz linux-dev-53918994b7c8c3bf0af5f641e1f299856799d883.zip | |
[PATCH] mac80211: fix iff_promiscs, iff_allmultis race
When we update the counters iff_promiscs and iff_allmultis
in struct ieee80211_local we have no common lock held to
protect them. The problem is that the update to each counter
may not be atomic, so we could end up with iff_promiscs == -1
in unfortunate conditions. To fix it, use atomic_t values.
It doesn't matter whether the two counters are updated
together atomically or not, if there are two invocations
of set_multicast_list we will end up with multiple
configure_filter() invocations of which the latter will always
be correct.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/ieee80211.c')
| -rw-r--r-- | net/mac80211/ieee80211.c | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/net/mac80211/ieee80211.c b/net/mac80211/ieee80211.c index b1180536c335..2501bff0d15e 100644 --- a/net/mac80211/ieee80211.c +++ b/net/mac80211/ieee80211.c @@ -59,10 +59,10 @@ static void ieee80211_configure_filter(struct ieee80211_local *local) unsigned int changed_flags; unsigned int new_flags = 0; - if (local->iff_promiscs) + if (atomic_read(&local->iff_promiscs)) new_flags |= FIF_PROMISC_IN_BSS; - if (local->iff_allmultis) + if (atomic_read(&local->iff_allmultis)) new_flags |= FIF_ALLMULTI; if (local->monitors) @@ -521,17 +521,17 @@ static void ieee80211_set_multicast_list(struct net_device *dev) if (allmulti != sdata_allmulti) { if (dev->flags & IFF_ALLMULTI) - local->iff_allmultis++; + atomic_inc(&local->iff_allmultis); else - local->iff_allmultis--; + atomic_dec(&local->iff_allmultis); sdata->flags ^= IEEE80211_SDATA_ALLMULTI; } if (promisc != sdata_promisc) { if (dev->flags & IFF_PROMISC) - local->iff_promiscs++; + atomic_inc(&local->iff_promiscs); else - local->iff_promiscs--; + atomic_dec(&local->iff_promiscs); sdata->flags ^= IEEE80211_SDATA_PROMISC; } |