Hi, sorry, no I didn’t. I don’t have a testbed available right now to try this out quickly. Christian > On 6. Oct 2023, at 11:16, Linux regression tracking (Thorsten Leemhuis) <regressions@xxxxxxxxxxxxx> wrote: > > On 06.10.23 11:07, Christian Theune wrote: >> >> it seems that 6.6rc4 is affected as well: >> >> ---- >> commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f >> Author: Budimir Markovic <markovicbudimir@xxxxxxxxx> >> Date: Thu Aug 24 01:49:05 2023 -0700 >> >> net/sched: sch_hfsc: Ensure inner classes have fsc curve >> —— > > Did you actually try if the problem occurs with 6.6-rc4? That the commit > is in there is expected (everything that lands in stable trees has to go > to mainline first). > > Ciao, Thorsten > >> I have not found newer commits that would suggest they change any behaviour around this in any way, but I might be wrong. >> >> Christian >> >>> On 6. Oct 2023, at 11:01, Linux regression tracking (Thorsten Leemhuis) <regressions@xxxxxxxxxxxxx> wrote: >>> >>> On 06.10.23 10:37, Christian Theune wrote: >>>> >>>> (prefix, I was not aware of the regression reporting process and incorrectly reported this informally with the developers mentioned in the change) >>> >>> Don't worry too much about that, but thx for taking care of all the >>> details. FWIW, there is one more thing that would be good to know: >>> >>> Does the problem happen with mainline (e.g. 6.6-rc4) as well? That's >>> relevant, as different people might care[1]. >>> >>> Ciao, Thorsten >>> >>> [1] this among others is explained here: >>> https://linux-regtracking.leemhuis.info/post/frequent-reasons-why-linux-kernel-bug-reports-are-ignored/ >>> >>>> I upgraded from 6.1.38 to 6.1.55 this morning and it broke my traffic shaping script, leaving me with a non-functional uplink on a remote router. >>>> >>>> The script errors out like this: >>>> >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + ext=ispA >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + ext_ingress=ifb0 >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + modprobe ifb >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + modprobe act_mirred >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + tc qdisc del dev ispA root >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2061]: Error: Cannot delete qdisc with handle of zero. >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + true >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + tc qdisc del dev ispA ingress >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2064]: Error: Cannot find specified qdisc on specified device. >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + true >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + tc qdisc del dev ifb0 root >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2066]: Error: Cannot delete qdisc with handle of zero. >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + true >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + tc qdisc del dev ifb0 ingress >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2067]: Error: Cannot find specified qdisc on specified device. >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + true >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + tc qdisc add dev ispA handle ffff: ingress >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + ifconfig ifb0 up >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + tc filter add dev ispA parent ffff: protocol all u32 match u32 0 0 action mirred egress redirect dev ifb0 >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + tc qdisc add dev ifb0 root handle 1: hfsc default 1 >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + tc class add dev ifb0 parent 1: classid 1:999 hfsc rt m2 2.5gbit >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2053]: + tc class add dev ifb0 parent 1:999 classid 1:1 hfsc sc rate 50mbit >>>> Oct 06 05:49:22 wendy00 isp-setup-shaping-start[2077]: Error: Invalid parent - parent class must have FSC. >>>> >>>> The error message is also a bit weird (but that’s likely due to iproute2 being weird) as the CLI interface for `tc` and the error message do not map well. (I think I would have to choose `hfsc sc` on the parent to enable the FSC option which isn’t mentioned anywhere in the hfsc manpage). >>>> >>>> The breaking change was introduced in 6.1.53[1] and a multitude of other currently supported kernels: >>>> >>>> ---- >>>> commit a1e820fc7808e42b990d224f40e9b4895503ac40 >>>> Author: Budimir Markovic <markovicbudimir@xxxxxxxxx> >>>> Date: Thu Aug 24 01:49:05 2023 -0700 >>>> >>>> net/sched: sch_hfsc: Ensure inner classes have fsc curve >>>> >>>> [ Upstream commit b3d26c5702c7d6c45456326e56d2ccf3f103e60f ] >>>> >>>> HFSC assumes that inner classes have an fsc curve, but it is currently >>>> possible for classes without an fsc curve to become parents. This leads >>>> to bugs including a use-after-free. >>>> >>>> Don't allow non-root classes without HFSC_FSC to become parents. >>>> >>>> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") >>>> Reported-by: Budimir Markovic <markovicbudimir@xxxxxxxxx> >>>> Signed-off-by: Budimir Markovic <markovicbudimir@xxxxxxxxx> >>>> Acked-by: Jamal Hadi Salim <jhs@xxxxxxxxxxxx> >>>> Link: https://lore.kernel.org/r/20230824084905.422-1-markovicbudimir@xxxxxxxxx >>>> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> >>>> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> >>>> ---- >>>> >>>> Regards, >>>> Christian >>>> >>>> [1] https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.1.53 >>>> >>>> #regzbot introduced: a1e820fc7808e42b990d224f40e9b4895503ac40 >>>> >>>> >> >> Liebe Grüße, >> Christian Theune >> Liebe Grüße, Christian Theune -- Christian Theune · ct@xxxxxxxxxxxxxxx · +49 345 219401 0 Flying Circus Internet Operations GmbH · https://flyingcircus.io Leipziger Str. 70/71 · 06108 Halle (Saale) · Deutschland HR Stendal HRB 21169 · Geschäftsführer: Christian Theune, Christian Zagrodnick
