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
