On Wed, Jun 21, 2023 at 8:47 PM Florian Westphal <fw@xxxxxxxxx> wrote: > > Florent Revest <revest@xxxxxxxxxxxx> wrote: > > > in this case an initcall is failing and I think panic is preferrable > > > to a kernel that behaves like NF_CONNTRACK_FTP=n. > > > > In that case, it seems like what you'd want is > > nf_conntrack_standalone_init() to BUG() instead of returning an error > > then ? (so you'd never get to NF_CONNTRACK_FTP or any other if > > nf_conntrack failed to initialize) If this is the prefered behavior, > > then sure, why not. > > > > > AFAICS this problem is specific to NF_CONNTRACK_FTP=y > > > (or any other helper module, for that matter). > > > > Even with NF_CONNTRACK_FTP=m, the initialization failure in > > nf_conntrack_standalone_init() still happens. Therefore, the helper > > hashtable gets freed and when the nf_conntrack_ftp.ko module gets > > insmod-ed, it calls nf_conntrack_helpers_register() and this still > > causes a use-after-free. > > Can you send a v2 with a slightly reworded changelog? > > It should mention that one needs NF_CONNTRACK=y, so that when > the failure happens during the initcall (as oposed to module insertion), > nf_conntrack_helpers_register() can fail cleanly without followup splat? Sure! :) On it.
