This is a note to let you know that I've just added the patch titled
igb: cope with large MAX_SKB_FRAGS
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
igb-cope-with-large-max_skb_frags.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ba7c0372d53729d9f53a37cad8dd4a139159a06b
Author: Paolo Abeni <pabeni@xxxxxxxxxx>
Date: Fri Aug 16 17:20:34 2024 +0200
igb: cope with large MAX_SKB_FRAGS
[ Upstream commit 8aba27c4a5020abdf60149239198297f88338a8d ]
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 <jtluka@xxxxxxxxxx>
Reported-by: Jirka Hladky <jhladky@xxxxxxxxxx>
Reported-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
Tested-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx>
Tested-by: Corinna Vinschen <vinschen@xxxxxxxxxx>
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Corinna Vinschen <vinschen@xxxxxxxxxx>
Link: https://patch.msgid.link/20240816152034.1453285-1-vinschen@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c
index 4431e7693d45f..8c8894ef33886 100644
--- a/drivers/net/ethernet/intel/igb/igb_main.c
+++ b/drivers/net/ethernet/intel/igb/igb_main.c
@@ -4833,6 +4833,7 @@ 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
