From d1c87d36a655035f173288a12256fbc1de764538 Mon Sep 17 00:00:00 2001 From: Martin Habets Date: Mon, 4 Apr 2022 11:48:51 +0100 Subject: [PATCH] sfc: Do not free an empty page_ring [ Upstream commit 458f5d92df4807e2a7c803ed928369129996bf96 ] When the page_ring is not used page_ptr_mask is 0. Do not dereference page_ring[0] in this case. Fixes: 2768935a4660 ("sfc: reuse pages to avoid DMA mapping/unmapping costs") Reported-by: Taehee Yoo Signed-off-by: Martin Habets Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/sfc/rx_common.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/ethernet/sfc/rx_common.c b/drivers/net/ethernet/sfc/rx_common.c index 633ca77a26fd1..b925de9b43028 100644 --- a/drivers/net/ethernet/sfc/rx_common.c +++ b/drivers/net/ethernet/sfc/rx_common.c @@ -166,6 +166,9 @@ static void efx_fini_rx_recycle_ring(struct efx_rx_queue *rx_queue) struct efx_nic *efx = rx_queue->efx; int i; + if (unlikely(!rx_queue->page_ring)) + return; + /* Unmap and release the pages in the recycle ring. Remove the ring. */ for (i = 0; i <= rx_queue->page_ptr_mask; i++) { struct page *page = rx_queue->page_ring[i]; -- 2.30.2