Patch "tg3: Fix race condition in tg3_get_stats64()." has been added to the 4.9-stable tree

Patch "tg3: Fix race condition in tg3_get_stats64()." has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    tg3: Fix race condition in tg3_get_stats64().

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     tg3-fix-race-condition-in-tg3_get_stats64.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Wed Aug  9 10:32:06 PDT 2017
From: Michael Chan <michael.chan@broadcom.com>
Date: Fri, 6 Jan 2017 16:18:53 -0500
Subject: tg3: Fix race condition in tg3_get_stats64().

From: Michael Chan <michael.chan@broadcom.com>


[ 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>
---
 drivers/net/ethernet/broadcom/tg3.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/drivers/net/ethernet/broadcom/tg3.c
+++ b/drivers/net/ethernet/broadcom/tg3.c
@@ -8720,11 +8720,14 @@ static void tg3_free_consistent(struct t
 	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);
 }
 
 /*


Patches currently in stable-queue which might be from michael.chan@broadcom.com are

queue-4.9/tg3-fix-race-condition-in-tg3_get_stats64.patch