Lorenzo Bianconi <lorenzo@xxxxxxxxxx> wrote: > From: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> > > Since we want to allow user to set some fields in nf_conn after it is > allocated but before it is inserted, we can permit BPF_WRITE for normal > nf_conn, and then mark return value as read only on insert, preventing > further BPF_WRITE. This way, nf_conn can be written to using normal > BPF instructions after allocation, but not after insertion. > > Note that we special nf_conn a bit here, inside the btf_struct_access > callback for XDP and TC programs. Since this is the only struct for > these programs requiring such adjustments, making this mechanism > more generic has been left as an exercise for a future patch adding > custom callbacks for more structs. Are you sure this is safe? As far as I can see this allows nf_conn->status = ~0ul. I'm fairly sure this isn't a good idea, see nf_ct_delete() for example.
