mac80211: Fix kernel panic due to use of txq after free
diff mbox series

Message ID 1555399480-30537-1-git-send-email-bperumal@codeaurora.org
State New
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Series
  • mac80211: Fix kernel panic due to use of txq after free
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Commit Message

Bhagavathi Perumal S April 16, 2019, 7:24 a.m. UTC
The txq of vif is added to active_txqs list for ATF TXQ scheduling
in the function ieee80211_queue_skb(), but it was not properly removed
before freeing the txq object. It was causing use after free of the txq
objects from the active_txqs list, result was kernel panic
due to invalid memory access.

Fix kernel invalid memory access by properly removing txq object
from active_txqs list before free the object.

Signed-off-by: Bhagavathi Perumal S <bperumal@codeaurora.org>
---
 net/mac80211/iface.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Toke Høiland-Jørgensen April 16, 2019, 8:49 a.m. UTC | #1
Bhagavathi Perumal S <bperumal@codeaurora.org> writes:

> The txq of vif is added to active_txqs list for ATF TXQ scheduling
> in the function ieee80211_queue_skb(), but it was not properly removed
> before freeing the txq object. It was causing use after free of the txq
> objects from the active_txqs list, result was kernel panic
> due to invalid memory access.
>
> Fix kernel invalid memory access by properly removing txq object
> from active_txqs list before free the object.
>
> Signed-off-by: Bhagavathi Perumal S <bperumal@codeaurora.org>

Nice catch, thanks!

Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>

This should probably have a fixes tag:

Fixes: 1866760096bf ("mac80211: Add TXQ scheduling API")

-Toke

Patch
diff mbox series

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 94459b2..410685d 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -1907,6 +1907,9 @@  void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
 	list_del_rcu(&sdata->list);
 	mutex_unlock(&sdata->local->iflist_mtx);
 
+	if (sdata->vif.txq)
+		ieee80211_txq_purge(sdata->local, to_txq_info(sdata->vif.txq));
+
 	synchronize_rcu();
 
 	if (sdata->dev) {