sfc: fix dereference of table before it is null checked

Currently pointer table is being dereferenced on a null check of
table->must_restore_filters before it is being null checked, leading
to a potential null pointer dereference issue.  Fix this by null
checking table before dereferencing it when checking for a null
table->must_restore_filters.

Addresses-Coverity: ("Dereference before null check")
Fixes: e4fe938cff04 ("sfc: move 'must restore' flags out of ef10-specific nic_data")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Acked-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/sfc/mcdi_filters.c b/drivers/net/ethernet/sfc/mcdi_filters.c
index 88de95a..455a628 100644 (file)
--- a/drivers/net/ethernet/sfc/mcdi_filters.c
+++ b/drivers/net/ethernet/sfc/mcdi_filters.c
@@ -1369,10 +1369,7 @@ void efx_mcdi_filter_table_restore(struct efx_nic *efx)
 
        WARN_ON(!rwsem_is_locked(&efx->filter_sem));
 
-       if (!table->must_restore_filters)
-               return;
-
-       if (!table)
+       if (!table || !table->must_restore_filters)
                return;
 
        down_write(&table->lock);