LinuxKPI: 802.11: reset chanctx when recycling

When we no longer need a channel context and put it back on the
reserved list, zero it for all but the vif so that we get the same
state as if it was freshly allocated.

Sponsored by:	The FreeBSD Foundation
Fixes:		e62c92c0a5, 88cb1e17f4
MFC after:	3 days

sys/compat/linuxkpi/common/src/linux_80211.c

@@ -2426,6 +2426,8 @@ lkpi_set_chanctx_conf(struct ieee80211_hw *hw, struct ieee80211_vif *vif,
 		rcu_assign_pointer(vif->bss_conf.chanctx_conf, NULL);
 		lchanctx = CHANCTX_CONF_TO_LCHANCTX(chanctx_conf);
 		list_del(&lchanctx->entry);
+		memset(lchanctx, 0, sizeof(*lchanctx));
+		lchanctx->lvif = VIF_TO_LVIF(vif);
 		list_add_rcu(&lchanctx->entry, &lhw->lchanctx_list_reserved);
 	}
 
@@ -2460,6 +2462,8 @@ lkpi_remove_chanctx(struct ieee80211_hw *hw, struct ieee80211_vif *vif)
 	lchanctx = CHANCTX_CONF_TO_LCHANCTX(chanctx_conf);
 	list_del(&lchanctx->entry);
 	lhw = HW_TO_LHW(hw);
+	memset(lchanctx, 0, sizeof(*lchanctx));
+	lchanctx->lvif = VIF_TO_LVIF(vif);
 	list_add_rcu(&lchanctx->entry, &lhw->lchanctx_list_reserved);
 }
 
@@ -6806,6 +6810,7 @@ linuxkpi_ieee80211_iffree(struct ieee80211_hw *hw)
 				lkpi_80211_mo_remove_chanctx(hw, chanctx_conf);
 			}
 			list_del(&lchanctx->entry);
+			/* No need to reset the lchanctx here as we will free it below. */
 			list_add_rcu(&lchanctx->entry, &lhw->lchanctx_list_reserved);
 		}
 	}