tg3: Fix race condition in tg3_get_stats64().

[ Upstream commit f5992b72ebe0dde488fa8f706b887194020c66fc ]

The driver's ndo_get_stats64() method is not always called under RTNL.
So it can race with driver close or ethtool reconfigurations.  Fix the
race condition by taking tp->lock spinlock in tg3_free_consistent()
when freeing the tp->hw_stats memory block.  tg3_get_stats64() is
already taking tp->lock.

Reported-by: Wang Yufen <wangyufen@huawei.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/ethernet/broadcom/tg3.c b/drivers/net/ethernet/broadcom/tg3.c
index 63c297c56ad4d4fa11756114d6993b2239de9811..a79e73781c0bbb8c94c9f55085284037ecea7347 100644 (file)
--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -8705,11 +8705,14 @@ static void tg3_free_consistent(struct tg3 *tp)
        tg3_mem_rx_release(tp);
        tg3_mem_tx_release(tp);
 
+       /* Protect tg3_get_stats64() from reading freed tp->hw_stats. */
+       tg3_full_lock(tp, 0);
        if (tp->hw_stats) {
                dma_free_coherent(&tp->pdev->dev, sizeof(struct tg3_hw_stats),
                                  tp->hw_stats, tp->stats_mapping);
                tp->hw_stats = NULL;
        }
+       tg3_full_unlock(tp);
 }
 
 /*