On 10.06.23 08:44, Bagas Sanjaya wrote: > On Tue, Jun 06, 2023 at 12:55:57PM +0200, Nicolas Escande wrote: >> Hello Felix, >> >> As user of the mesh part of mac80211 on multiple products at work let me say >> thank you for all the work you do on wifi, especially on 80211s, and especially >> the recent improvements you made for mesh fast RX/TX & cross vendor AMSDU compat >> >> We upgraded our kernel from an older (5.15) to a newer 6.4. The problem is STP >> doesn't work anymore and alas we use it for now (for the better or worse). >> >> What I gathered so far from my setup: >> - we use ath9k & ath10k >> - in my case STP frames are received as regular packet and not as amsdu >> - the received packets have a wrong length of 44 in tcpdump >> (instead of 38 with our previous kernel) >> - llc_fixup_skb() tries to pull some 41 bytes out of a 35 bytes packet >> this makes llc_rcv() discard the frames & breaks STP >> >> >From bisecting the culprit seems to be 986e43b19ae9176093da35e0a844e65c8bf9ede7 >> (wifi: mac80211: fix receiving A-MSDU frames on mesh interfaces) >> >> I guess that your changes to handle both ampdu subframes & normal frames in the >> same datapath ends up putting a wrong skb->len for STP (multicast) frames ? >> Honestly I don't understand enough of the 80211 internals & spec to pinpoint the >> exact problem. >> >> It seems this change was already in the 6.3 kernel so I guess someone should >> have seen it before (but I didn't find anything..) ? Maybe I missed something... >> >> Anyway I'm happy to provide more info or try anything you throw at me. >> > > Thanks for the regression report. I'm adding it to regzbot: > > (Felix: it looks like this regression is introcued by a commit authored by you. > Would you like to take a look on it?) > > #regzbot ^introduced: 986e43b19ae917 Hmmm, Felix did not reply. But let's ignore that for now. Nicolas, I noticed there are a few patches in next that refer to the culprit. Might be worth giving this series a try: https://lore.kernel.org/all/20230314095956.62085-1-nbd@xxxxxxxx/ Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat) -- Everything you wanna know about Linux kernel regression tracking: https://linux-regtracking.leemhuis.info/about/#tldr If I did something stupid, please tell me, as explained on that page.
