On Thu, Jun 07, 2018 at 05:12:51AM -0500, Alex Elder wrote: > On 06/07/2018 04:19 AM, Viresh Kumar wrote: > > On 07-06-18, 11:18, Johan Hovold wrote: > >> If you want to work around the warning and think you can do it in some > >> non-contrived way, then go for it. > >> > >> Clearing the request buffer, checking for termination using strnlen, and > >> then using memcpy might not be too bad. > >> > >> But after all, it is a false positive, so leaving things as they stand > >> is fine too. > > > > Leave it then :) > > > > It's interesting that the warning isn't reported for this in > fw_mgmt_interface_fw_version_operation(). The difference there is > that you actually put a zero byte at that last position before > returning. I'm mildly impressed if gcc is distinguishing that. Found a redhat blog post claiming it does check for some cases like that: https://developers.redhat.com/blog/2018/05/24/detecting-string-truncation-with-gcc-8/ > You *are* returning the fw_info->firmware_tag array newly filled > with a non-null-terminated string in one of the two cases that > get warnings in "fw-management.c". No, there's no warning for that one (line 250), and there fw_info is used as the source, not the destination, so no unterminated string is returned there either. > But the other one is only > updating a buffer in a local/automatic variable. All three cases, except the one that is explicitly terminated. > Weird. I wish there were a non-clumsy way of marking false positives > like this as A-OK. The gcc docs mentions an attribute for that but it seems a bit overkill here. Thanks, Johan
