Re: Wireguard iOS crashes after upgrading to XCode 14

[Andrej Mihajlov <and@mullvad.net>]

Hi Houman,

I believe that the crash coming from withMemoryRebound is actually assertion (assert()). Very often assertions are stripped out from release builds, so I guess it could be the reason why it just worked in release builds.

Jason has already replied in regards of releasing an update.

Best regards,
Andrej

> On 22 Sep 2022, at 10:56, Houman <houmie@gmail.com> wrote:
> 
> Hi Andrej,
> 
> It works, well done!
> 
> A strange thing though, before your patch I was still able to connect
> to the VPN server, if I changed the schema to Release instead of
> Debug.  Now with your patch it also works under Debug schema, which is
> fantastic.
> What could be the technical reason that it still worked under Release?
> 
> And what will happen now, are you able to actually get this patch
> released on the official repo? The repo hasn't been updated for a
> year.  :-)
> 
> Thanks,
> Houman
> 
> 
> On Thu, 22 Sept 2022 at 09:31, Andrej Mihajlov <and@mullvad.net> wrote:
>> 
>> Hi,
>> 
>> I think we have a bug. If I am right, basically in both IPv4 and IPv6 extensions, withMemoryRebound takes capacity which is actually a number of instances of a given type (sockaddr_ variant) and not the byte size of a struct.
>> 
>> Could you please patch your WireGuardKit with the following commit and see if it helps?
>> 
>> https://git.zx2c4.com/wireguard-apple/commit/?h=am/fix-addrinfo-crash
>> 
>> Best regards,
>> Andrey Mikhaylov
>> 
>>> On 13 Sep 2022, at 14:41, Houman <houmie@gmail.com> wrote:
>>> 
>>> My existing Wireguard iOS implementation stopped working after
>>> upgrading to Xcode 14 today.
>>> When trying to connect to servers that support only IPv4, then it's
>>> fine. But if the server supports both IPv6 and IPv4 then the tunnel
>>> crashes:
>>> 
>>> This IPv6 extension in
>>> wireguard-apple/Sources/WireGuardKit/IPAddress+AddrInfo.swift crashes
>>> with a Fatal Error at addrInfo.ai_addr.withMemoryRebound()
>>> 
>>> The whole extension below:
>>> 
>>> extension IPv6Address {
>>>   init?(addrInfo: addrinfo) {
>>>       guard addrInfo.ai_family == AF_INET6 else { return nil }
>>> 
>>>       let addressData = addrInfo.ai_addr.withMemoryRebound(to:
>>> sockaddr_in6.self, capacity: MemoryLayout<sockaddr_in6>.size) { ptr ->
>>> Data in
>>>           return Data(bytes: &ptr.pointee.sin6_addr, count:
>>> MemoryLayout<in6_addr>.size)
>>>       }
>>>       self.init(addressData)
>>>   }
>>> }
>>> 
>>> Has anyone else experienced this problem?
>>> 
>>> Thanks,
>>