From 8aba27c4a5020abdf60149239198297f88338a8d Mon Sep 17 00:00:00 2001 From: Paolo Abeni Date: Fri, 16 Aug 2024 17:20:34 +0200 Subject: [PATCH] igb: cope with large MAX_SKB_FRAGS Sabrina reports that the igb driver does not cope well with large MAX_SKB_FRAG values: setting MAX_SKB_FRAG to 45 causes payload corruption on TX. An easy reproducer is to run ssh to connect to the machine. With MAX_SKB_FRAGS=17 it works, with MAX_SKB_FRAGS=45 it fails. This has been reported originally in https://bugzilla.redhat.com/show_bug.cgi?id=2265320 The root cause of the issue is that the driver does not take into account properly the (possibly large) shared info size when selecting the ring layout, and will try to fit two packets inside the same 4K page even when the 1st fraglist will trump over the 2nd head. Address the issue by checking if 2K buffers are insufficient. Fixes: 3948b05950fd ("net: introduce a config option to tweak MAX_SKB_FRAGS") Reported-by: Jan Tluka Reported-by: Jirka Hladky Reported-by: Sabrina Dubroca Tested-by: Sabrina Dubroca Tested-by: Corinna Vinschen Signed-off-by: Paolo Abeni Signed-off-by: Corinna Vinschen Link: https://patch.msgid.link/20240816152034.1453285-1-vinschen@redhat.com Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/intel/igb/igb_main.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index 11be39f435f3..33a42b4c21e0 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -4808,6 +4808,7 @@ static void igb_set_rx_buffer_len(struct igb_adapter *adapter, #if (PAGE_SIZE < 8192) if (adapter->max_frame_size > IGB_MAX_FRAME_BUILD_SKB || + IGB_2K_TOO_SMALL_WITH_PADDING || rd32(E1000_RCTL) & E1000_RCTL_SBP) set_ring_uses_large_buffer(rx_ring); #endif -- 2.39.5