On 10/25/2023 8:52 AM, Jeff Johnson wrote: > On 10/24/2023 7:37 PM, Gustavo A. R. Silva wrote: >> >> >> On 10/24/23 14:49, Johannes Berg wrote: >>> On Tue, 2023-10-24 at 14:41 -0600, Gustavo A. R. Silva wrote: >>>> >>>> It seems we run into the same issue in the function below, even in the >>>> case this `memset()` is unnecessary (which it seems it's not): >>>> >>>> 8920 memset(skb->data, 0, sizeof(*cmd)); >>>> >>>> Notice that if `cap->peer_chan_len == 0` or `cap->peer_chan_len == 1`, >>>> in the original code, we have `len == sizeof(*cmd) == 128`: >>> >>> Right. >>> >>>> - /* tdls peer update cmd has place holder for one channel*/ >>>> - chan_len = cap->peer_chan_len ? (cap->peer_chan_len - 1) : 0; >>>> - >>>> - len = sizeof(*cmd) + chan_len * sizeof(*chan); >>>> + len = struct_size(cmd, peer_capab.peer_chan_list, >>>> cap->peer_chan_len); >>>> >>>> skb = ath10k_wmi_alloc_skb(ar, len); >>>> if (!skb) >>>> >>>> which makes `round_len == roundup(len, 4) == struct_size(cmd,...,...) >>>> == 104` >>>> when `cap->peer_chan_len == 0` >>> >>> And yeah, that's really the issue, it only matters for ==0. For a moment >>> there I thought that doesn't even make sense, but it looks like it never >>> even becomes non-zero. >>> >>> No idea then, sorry. You'd hope firmware doesn't care about the actual >>> message size if the inner data says "0 entries", but who knows? And how >>> many firmware versions are there? :) >>> >>> So I guess you'd want to stay compatible, even if it means having a >>> >>> chan_len = min(cap->peer_chan_len, 1); >>> >>> for the struct_size()? >> >> Yeah, that's an alternative. >> >> I'll wait for the maintainers to chime in and see if they have a different >> opinion. > > I'm seeing clarification from the development team. > > /jeff > I was not able to get a response from the firmware team. I have gone ahead and created a series of patches to fix the remaining flexible array issues in ath10k including the one discussed here. I should be able to post those sometime this week. /jeff
