[PATCH 6.12 075/337] forcedeth: fix UAF of txrx_stats in nv_remove

Greg Kroah-Hartman <[email protected]>
Newsgroups dev.linux.lists.patches,org.kernel.vger.stable
Message-ID <[email protected]>
6.12-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Chenguang Zhao <[email protected]>

[ Upstream commit 22666ba1420164753d7b0f5a841986b25ace5435 ]

nv_remove() frees the per-CPU txrx_stats before unregister_netdev().
Until unregister completes, ndo_get_stats64, the NAPI/xmit data path,
and nv_close()/drain may still access txrx_stats, leading to a
use-after-free.

Free the stats only after unregister_netdev().

Fixes: f4b633b911fd ("forcedeth: use per cpu to collect xmit/recv statistics")
Signed-off-by: Chenguang Zhao <[email protected]>
Reviewed-by: Vadim Fedorenko <[email protected]>
Reviewed-by: Zhu Yanjun <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
 drivers/net/ethernet/nvidia/forcedeth.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c
index 720f577929dbf..11eb3751ad27b 100644
--- a/drivers/net/ethernet/nvidia/forcedeth.c
+++ b/drivers/net/ethernet/nvidia/forcedeth.c
@@ -6199,10 +6199,10 @@ static void nv_remove(struct pci_dev *pci_dev)
 	struct net_device *dev = pci_get_drvdata(pci_dev);
 	struct fe_priv *np = netdev_priv(dev);
 
-	free_percpu(np->txrx_stats);
-
 	unregister_netdev(dev);
 
+	free_percpu(np->txrx_stats);
+
 	nv_restore_mac_addr(pci_dev);
 
 	/* restore any phy related changes */
-- 
2.53.0
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