diff mbox series

[-next] ixgbe: don't clear_bit on xdp_ring->state if xdp_ring is null

Message ID 20181004175732.28329-1-colin.king@canonical.com
State Accepted
Delegated to: Jeff Kirsher
Headers show
Series [-next] ixgbe: don't clear_bit on xdp_ring->state if xdp_ring is null | expand

Commit Message

Colin Ian King Oct. 4, 2018, 5:57 p.m. UTC 
From: Colin Ian King <colin.king@canonical.com>

There is an earlier check to see if xdp_ring is null when configuring
the tx ring, so assuming that it can still be null, the clearing of
the xdp_ring->state currently could end up with a null pointer
dereference.  Fix this by only clearing the bit if xdp_ring is not null.

Detected by CoverityScan, CID#1473795 ("Dereference after null check")

Fixes: 024aa5800f32 ("ixgbe: added Rx/Tx ring disable/enable functions")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Comments

Bowers, AndrewX Oct. 8, 2018, 6:38 p.m. UTC | #1 
> -----Original Message-----
> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On
> Behalf Of Colin King
> Sent: Thursday, October 4, 2018 10:58 AM
> To: Kirsher, Jeffrey T <jeffrey.t.kirsher@intel.com>; David S . Miller
> <davem@davemloft.net>; intel-wired-lan@lists.osuosl.org;
> netdev@vger.kernel.org
> Cc: kernel-janitors@vger.kernel.org
> Subject: [Intel-wired-lan] [PATCH][-next] ixgbe: don't clear_bit on xdp_ring-
> >state if xdp_ring is null
> 
> From: Colin Ian King <colin.king@canonical.com>
> 
> There is an earlier check to see if xdp_ring is null when configuring the tx ring,
> so assuming that it can still be null, the clearing of the xdp_ring->state
> currently could end up with a null pointer dereference.  Fix this by only
> clearing the bit if xdp_ring is not null.
> 
> Detected by CoverityScan, CID#1473795 ("Dereference after null check")
> 
> Fixes: 024aa5800f32 ("ixgbe: added Rx/Tx ring disable/enable functions")
> Signed-off-by: Colin Ian King <colin.king@canonical.com>
> ---
>  drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)

Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 0049a2becd7e..8e4756247324 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -10517,7 +10517,8 @@  void ixgbe_txrx_ring_enable(struct ixgbe_adapter *adapter, int ring)
 	ixgbe_configure_rx_ring(adapter, rx_ring);
 
 	clear_bit(__IXGBE_TX_DISABLED, &tx_ring->state);
-	clear_bit(__IXGBE_TX_DISABLED, &xdp_ring->state);
+	if (xdp_ring)
+		clear_bit(__IXGBE_TX_DISABLED, &xdp_ring->state);
 }
 
 /**