When igb_set_interrupt_capability() calls
igb_reset_interrupt_capability() (e.g., because CONFIG_PCI_MSI is unset),
num_q_vectors has been set but no vector has yet been allocated.

igb_reset_interrupt_capability() will then call igb_reset_q_vector,
which assumes that the vector is allocated. As this is not the case, we
are accessing a NULL-pointer.

This patch fixes it by checking that q_vector is indeed different from
NULL.

Fixes: 02ef6e1d0b0023 (igb: Fix queue allocation method to accommodate changing 
during runtime)
Cc: Carolyn Wyborny <[email protected]>
Signed-off-by: Christoph Paasch <[email protected]>
---
 drivers/net/ethernet/intel/igb/igb_main.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c 
b/drivers/net/ethernet/intel/igb/igb_main.c
index 46d31a49f5ea..bfcf192ee87d 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -1014,6 +1014,12 @@ static void igb_reset_q_vector(struct igb_adapter 
*adapter, int v_idx)
 {
        struct igb_q_vector *q_vector = adapter->q_vector[v_idx];
 
+       /* Coming from igb_set_interrupt_capability, the vectors are not yet
+        * allocated. So, q_vector is NULL so we should stop here.
+        */
+       if (!q_vector)
+               return;
+
        if (q_vector->tx.ring)
                adapter->tx_ring[q_vector->tx.ring->queue_index] = NULL;
 
-- 
1.8.3.2


------------------------------------------------------------------------------
Managing the Performance of Cloud-Based Applications
Take advantage of what the Cloud has to offer - Avoid Common Pitfalls.
Read the Whitepaper.
http://pubads.g.doubleclick.net/gampad/clk?id=121054471&iu=/4140/ostg.clktrk
_______________________________________________
E1000-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/e1000-devel
To learn more about Intel&#174; Ethernet, visit 
http://communities.intel.com/community/wired

Reply via email to