Commit 2965c4cd authored by Johannes Berg's avatar Johannes Berg Committed by Kalle Valo

wifi: mac80211: fix use-after-free in chanctx code

In ieee80211_vif_use_reserved_context(), when we have an
old context and the new context's replace_state is set to
IEEE80211_CHANCTX_REPLACE_NONE, we free the old context
in ieee80211_vif_use_reserved_reassign(). Therefore, we
cannot check the old_ctx anymore, so we should set it to
NULL after this point.

However, since the new_ctx replace state is clearly not
IEEE80211_CHANCTX_REPLACES_OTHER, we're not going to do
anything else in this function and can just return to
avoid accessing the freed old_ctx.

Cc: stable@vger.kernel.org
Fixes: 5bcae31d ("mac80211: implement multi-vif in-place reservations")
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarKalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220601091926.df419d91b165.I17a9b3894ff0b8323ce2afdb153b101124c821e5@changeid
parent 7711fe71
......@@ -1749,12 +1749,9 @@ int ieee80211_vif_use_reserved_context(struct ieee80211_sub_if_data *sdata)
if (new_ctx->replace_state == IEEE80211_CHANCTX_REPLACE_NONE) {
if (old_ctx)
err = ieee80211_vif_use_reserved_reassign(sdata);
else
err = ieee80211_vif_use_reserved_assign(sdata);
return ieee80211_vif_use_reserved_reassign(sdata);
if (err)
return err;
return ieee80211_vif_use_reserved_assign(sdata);
}
/*
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment