From 7128c834d30e6b2cf649f14d8fc274941786d0e1 Mon Sep 17 00:00:00 2001 From: Cristian Dumitrescu Date: Mon, 11 Jan 2021 18:11:38 +0000 Subject: i40e: fix potential NULL pointer dereferencing MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, the function i40e_construct_skb_zc only frees the input xdp buffer when the output skb is successfully built. On error, the function i40e_clean_rx_irq_zc does not commit anything for the current packet descriptor and simply exits the packet descriptor processing loop, with the plan to restart the processing of this descriptor on the next invocation. Therefore, on error the ring next-to-clean pointer should not advance, the xdp i.e. *bi buffer should not be freed and the current buffer info should not be invalidated by setting *bi to NULL. Therefore, the *bi should only be set to NULL when the function i40e_construct_skb_zc is successful, otherwise a NULL *bi will be dereferenced when the work for the current descriptor is eventually restarted. Fixes: 3b4f0b66c2b3 ("i40e, xsk: Migrate to new MEM_TYPE_XSK_BUFF_POOL") Signed-off-by: Cristian Dumitrescu Acked-by: Björn Töpel Link: https://lore.kernel.org/r/20210111181138.49757-1-cristian.dumitrescu@intel.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/intel/i40e/i40e_xsk.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/net') diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c index 47eb9c584a12..492ce213208d 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c @@ -348,12 +348,12 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget) * SBP is *not* set in PRT_SBPVSI (default not set). */ skb = i40e_construct_skb_zc(rx_ring, *bi); - *bi = NULL; if (!skb) { rx_ring->rx_stats.alloc_buff_failed++; break; } + *bi = NULL; cleaned_count++; i40e_inc_ntc(rx_ring); -- cgit v1.2.3