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From: Pavel Skripkin <paskripkin@gmail.com>
To: davem@davemloft.net, kuba@kernel.org, qiangqing.zhang@nxp.com,
	hslester96@gmail.com, fugang.duan@nxp.com
Cc: dan.carpenter@oracle.com, netdev@vger.kernel.org,
	linux-kernel@vger.kernel.org,
	Pavel Skripkin <paskripkin@gmail.com>
Subject: [PATCH 1/2] net: fec: fix use-after-free in fec_drv_remove
Date: Wed,  4 Aug 2021 18:51:51 +0300	[thread overview]
Message-ID: <25ad9ae695546c0ce23edb25cb2a67575cbda26b.1628091954.git.paskripkin@gmail.com> (raw)
In-Reply-To: <cover.1628091954.git.paskripkin@gmail.com>

Smatch says:
	drivers/net/ethernet/freescale/fec_main.c:3994 fec_drv_remove() error: Using fep after free_{netdev,candev}(ndev);
	drivers/net/ethernet/freescale/fec_main.c:3995 fec_drv_remove() error: Using fep after free_{netdev,candev}(ndev);

Since fep pointer is netdev private data, accessing it after free_netdev()
call can cause use-after-free bug. Fix it by moving free_netdev() call at
the end of the function

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: a31eda65ba21 ("net: fec: fix clock count mis-match")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
---
 drivers/net/ethernet/freescale/fec_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/freescale/fec_main.c b/drivers/net/ethernet/freescale/fec_main.c
index 8aea707a65a7..7e4c4980ced7 100644
--- a/drivers/net/ethernet/freescale/fec_main.c
+++ b/drivers/net/ethernet/freescale/fec_main.c
@@ -3843,13 +3843,13 @@ fec_drv_remove(struct platform_device *pdev)
 	if (of_phy_is_fixed_link(np))
 		of_phy_deregister_fixed_link(np);
 	of_node_put(fep->phy_node);
-	free_netdev(ndev);
 
 	clk_disable_unprepare(fep->clk_ahb);
 	clk_disable_unprepare(fep->clk_ipg);
 	pm_runtime_put_noidle(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
 
+	free_netdev(ndev);
 	return 0;
 }
 
-- 
2.32.0


  reply	other threads:[~2021-08-04 15:52 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-04 15:48 [PATCH 0/2] net: fix use-after-free bugs Pavel Skripkin
2021-08-04 15:51 ` Pavel Skripkin [this message]
2021-08-05  2:24   ` [PATCH 1/2] net: fec: fix use-after-free in fec_drv_remove Joakim Zhang
2021-08-04 15:52 ` [PATCH 2/2] net: vxge: fix use-after-free in vxge_device_unregister Pavel Skripkin
2021-08-04 18:38 ` [PATCH 0/2] net: fix use-after-free bugs Jesse Brandeburg
2021-08-05 14:50 ` patchwork-bot+netdevbpf

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