On Thu, 25 Mar 2021 09:07:23 +0100, Kurt Van Dijck wrote:

On Thu, 25 Mar 2021 08:31:09 +0100, Oliver Hartkopp wrote:

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On 24.03.21 23:19, Richard Weinberger wrote:

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Oliver,

----- Ursprüngliche Mail -----

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@@ -808,10 +810,13 @@ static int raw_recvmsg(struct socket *sock, struct msghdr

*msg, size_t size,
int noblock;

noblock = flags & MSG_DONTWAIT;
flags &= ~MSG_DONTWAIT;

+	if (msg->msg_name && msg->msg_namelen < RAW_MIN_NAMELEN)
+		return -EINVAL;
+

This indeed fails. There exists a thin layer between the syscall and
socket's recvmsg that puts a seperate sockaddr and length 0 :-(

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Like with Kurt's patch, my test fails here too because msg->msg_namelen is 0.
->msg_namelen is always 0 in the recvfrom() case.

Agreed!

I just adopted that part and did no more testing yesterday (needed some
sleep).

E.g. 'candump any' also fails at CAN frame reception time due to this wrong
check ;-)

I'd like to understand how this check is wrong.
msg->msg_namelen should contain the size of msg->msg_name, isn't it.
if that is less than RAW_MIN_NAMELEN, you can't store the address.

candump sets msg->msg_namelen to sizeof(), so it is not 0.

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Will send an update soon.

looking forward
Kurt