On Wed, Feb 23, 2022 at 04:50:18PM -0800, Jeff Johnson wrote: > On 2/22/2022 6:38 PM, Gustavo A. R. Silva wrote: > > Replace one-element array with flexible-array member in struct > > wmi_connect_event. > > > > It's also worth noting that due to the flexible array transformation, > > the size of struct wmi_connect_event changed (now the size is 1 byte > > smaller), and in order to preserve the logic of before the transformation, > > the following change is needed: > > > > - if (len < sizeof(struct wmi_connect_event)) > > + if (len <= sizeof(struct wmi_connect_event)) > > > > This issue was found with the help of Coccinelle and audited and fixed, > > manually. > > > > Link: https://www.kernel.org/doc/html/v5.16/process/deprecated.html#zero-length-and-one-element-arrays > > Link: https://github.com/KSPP/linux/issues/79 > > Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx> > > --- > > Hi! > > > > It'd be great if someone can confirm or comment on the following > > changes described in the changelog text: > > > > - if (len < sizeof(struct wmi_connect_event)) > > + if (len <= sizeof(struct wmi_connect_event)) > > > > Thanks > > > > drivers/net/wireless/ath/ath6kl/wmi.c | 2 +- > > drivers/net/wireless/ath/ath6kl/wmi.h | 2 +- > > 2 files changed, 2 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/net/wireless/ath/ath6kl/wmi.c b/drivers/net/wireless/ath/ath6kl/wmi.c > > index 049d75f31f3c..ccdccead688e 100644 > > --- a/drivers/net/wireless/ath/ath6kl/wmi.c > > +++ b/drivers/net/wireless/ath/ath6kl/wmi.c > > @@ -857,7 +857,7 @@ static int ath6kl_wmi_connect_event_rx(struct wmi *wmi, u8 *datap, int len, > > struct wmi_connect_event *ev; > > u8 *pie, *peie; > > - if (len < sizeof(struct wmi_connect_event)) > > + if (len <= sizeof(struct wmi_connect_event)) > > this is another case where IMO the original code can remain since all it is > really checking is to see if the entire "fixed" portion is present. in > reality if there was just one byte of assoc_info the response would actually > be invalid. I see; that's actually what I needed to be clarified. I wasn't sure if a channel list with no channels was valid and expected. Now I see it is. :) > what is missing is logic that verifies len is large enough to hold the > payload that is advertised via the beacon_ie_len, assoc_req_len, & > assoc_resp_len members. without this even if you change the initial len > check you can have a condition where len says there is one u8 in assoc_info > (and pass the initial test) but the other three members indicate that much > more data is present. > > but that is a pre-existing shortcoming that should be handled with a > separate patch. Yeah; I'll consider extending this series to include a patch for that. > > return -EINVAL; > > ev = (struct wmi_connect_event *) datap; > > diff --git a/drivers/net/wireless/ath/ath6kl/wmi.h b/drivers/net/wireless/ath/ath6kl/wmi.h > > index 432e4f428a4a..6b064e669d87 100644 > > --- a/drivers/net/wireless/ath/ath6kl/wmi.h > > +++ b/drivers/net/wireless/ath/ath6kl/wmi.h > > @@ -1545,7 +1545,7 @@ struct wmi_connect_event { > > u8 beacon_ie_len; > > u8 assoc_req_len; > > u8 assoc_resp_len; > > - u8 assoc_info[1]; > > + u8 assoc_info[]; > > } __packed; > > /* Disconnect Event */ > > whether or not you modify the length check consider this: > Reviewed-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx> Great. :) Thanks a lot for the feedback! -- Gustavo
