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authorJacob Keller <jacob.e.keller@intel.com>2016-06-03 15:42:12 -0700
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2016-07-20 15:22:09 -0700
commitb624714bc90064eeefd9ba7564e90865eef00421 (patch)
tree3cb5a3c9a916c1e2d31fd3df993399d7471e9810 /drivers/net/ethernet/intel
parentfm10k: no need to continue in fm10k_down if __FM10K_DOWN already set (diff)
downloadlinux-dev-b624714bc90064eeefd9ba7564e90865eef00421.tar.xz
linux-dev-b624714bc90064eeefd9ba7564e90865eef00421.zip
fm10k: avoid possible null pointer dereference in fm10k_update_stats
It's currently possible for fm10k_update_stats to be called during the window when we go down and the rings are removed. This can result in a null pointer dereference. In fm10k_get_stats64 we work around this by using ACCESS_ONCE and a null pointer check inside the loop. Use this same flow in the fm10k_update_stats to avoid the potential null pointer. Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Tested-by: Krishneil Singh <Krishneil.k.singh@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers/net/ethernet/intel')
-rw-r--r--drivers/net/ethernet/intel/fm10k/fm10k_pci.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_pci.c b/drivers/net/ethernet/intel/fm10k/fm10k_pci.c
index 610c313610c8..be0b7dea6e72 100644
--- a/drivers/net/ethernet/intel/fm10k/fm10k_pci.c
+++ b/drivers/net/ethernet/intel/fm10k/fm10k_pci.c
@@ -377,7 +377,10 @@ void fm10k_update_stats(struct fm10k_intfc *interface)
/* gather some stats to the interface struct that are per queue */
for (bytes = 0, pkts = 0, i = 0; i < interface->num_tx_queues; i++) {
- struct fm10k_ring *tx_ring = interface->tx_ring[i];
+ struct fm10k_ring *tx_ring = READ_ONCE(interface->tx_ring[i]);
+
+ if (!tx_ring)
+ continue;
restart_queue += tx_ring->tx_stats.restart_queue;
tx_busy += tx_ring->tx_stats.tx_busy;
@@ -396,7 +399,10 @@ void fm10k_update_stats(struct fm10k_intfc *interface)
/* gather some stats to the interface struct that are per queue */
for (bytes = 0, pkts = 0, i = 0; i < interface->num_rx_queues; i++) {
- struct fm10k_ring *rx_ring = interface->rx_ring[i];
+ struct fm10k_ring *rx_ring = READ_ONCE(interface->rx_ring[i]);
+
+ if (!rx_ring)
+ continue;
bytes += rx_ring->stats.bytes;
pkts += rx_ring->stats.packets;