4.4-stable review patch.  If anyone has any objections, please let me know.

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

From: Bo Chen <che...@pdx.edu>

[ Upstream commit cf1acec008f8d7761aa3fd7c4bca7e17b2d2512d ]

When the device is not up, the call to 'e1000_up()' from the error handling path
of 'e1000_set_ringparam()' causes a kernel oops with a null-pointer
dereference. The null-pointer dereference is triggered in function
'e1000_alloc_rx_buffers()' at line 'buffer_info = &rx_ring->buffer_info[i]'.

This bug was reported by COD, a tool for testing kernel module binaries I am
building. This bug was also detected by KFI from Dr. Kai Cong.

This patch fixes the bug by checking on 'netif_running()' before calling
'e1000_up()' in 'e1000_set_ringparam()'.

Signed-off-by: Bo Chen <che...@pdx.edu>
Acked-by: Alexander Duyck <alexander.h.du...@intel.com>
Tested-by: Aaron Brown <aaron.f.br...@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com>
Signed-off-by: Sasha Levin <alexander.le...@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/net/ethernet/intel/e1000/e1000_ethtool.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
+++ b/drivers/net/ethernet/intel/e1000/e1000_ethtool.c
@@ -665,7 +665,8 @@ err_setup_rx:
 err_alloc_rx:
        kfree(txdr);
 err_alloc_tx:
-       e1000_up(adapter);
+       if (netif_running(adapter->netdev))
+               e1000_up(adapter);
 err_setup:
        clear_bit(__E1000_RESETTING, &adapter->flags);
        return err;


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