[PATCH 2/2] staging: octeon: add missing napi_disable in cvm_oct_rx_shutdown

[Ayush Mukkanwar]

cvm_oct_rx_shutdown calls free_irq and netif_napi_del without
disabling the napi instance first. As the free_irq only waits
for completion of hard interrupt handlers, the napi poll
function could still be active. If cvm_oct_remove proceeds to
free the plat structure (which holds the NAPI instances), the
active poll function will access freed memory, resulting in a
use-after-free crash.

Signed-off-by: Ayush Mukkanwar <ayushmukkanwar@xxxxxxxxx>
---
 drivers/staging/octeon/ethernet-rx.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/staging/octeon/ethernet-rx.c b/drivers/staging/octeon/ethernet-rx.c
index cd36b5ba6f6c..3e9d58d32156 100644
--- a/drivers/staging/octeon/ethernet-rx.c
+++ b/drivers/staging/octeon/ethernet-rx.c
@@ -535,6 +535,8 @@ void cvm_oct_rx_shutdown(struct platform_device *pdev)
 		else
 			cvmx_write_csr(CVMX_POW_WQ_INT_THRX(i), 0);
 
+		napi_disable(&plat->rx_group[i].napi);
+
 		/* Free the interrupt handler */
 		free_irq(plat->rx_group[i].irq, &plat->rx_group[i].napi);
 
-- 
2.54.0