Ilya Maximets i.maximets@ovn.org wrote:
Hi, Florian.
There is a problem on 5.15 longterm tree where the offending commit got backported, but the previous one was not, so it triggers an issue while loading the openvswitch module.
To be more clear, v5.15.35 contains the following commit: 408bdcfce8df ("net: prefer nf_ct_put instead of nf_conntrack_put") backported as commit 72dd9e61fa319bc44020c2d365275fc8f6799bff, but it doesn't have the previous one: 6ae7989c9af0 ("netfilter: conntrack: avoid useless indirection during conntrack destruction") that adds the NULL pointer check to the nf_ct_put().
Either 6ae7989c9af0 should be backported to 5.15 or 72dd9e61fa31 reverted on that tree.
The commit was never meant to be backported to stable, it doesn't fix any bug.
I suspect it was done to take 'net/sched: act_ct: fix ref leak when switching zones' without munging it.
I suggest to add stable-only patch that makes nf_ct_put(NULL) legal, like in linux.git, but I don't know stable team preferences.