Dear all,
We are using lwIP 1.4.1 with a multitasking RTOS (FreeRTOS) and suffered
from unstability and crashes under heavy load, particularly when sending
lots of UDP packets to nonexisting IP's. The crashes seem to happen at
this location in etharp.c function etharp_query():
r = arp_table[i].q;
while (r->next != NULL) { // <-- access violation reading
from r->next (bus fault)
r = r->next;
}
r->next = new_entry; // <-- memory corruption may
happen here
The cause of the particular crash I was analyzing, was that the queue in
arp_table[].q had been freed at the same time as the while was following
the next pointers, leading to access violation.
It seems etharp.c is not written in a thread safe manner, while at the
same time being accessed by both the tcpip task in lwIP and the
application using lwIP. How can this ever be safe?
Is this due to an oversight in our implementation of lwIP or a bug in lwIP?
Best regards,
Lars
_______________________________________________
lwip-users mailing list
[email protected]
https://lists.nongnu.org/mailman/listinfo/lwip-users
