Stack smashing after thread finishes running

[sisco]

hi there,

i have a little problem with my qt software. the software uses usblib to connect to a custom made hid device. normally connecting/disconnecting the device works fine with the software detecting if the device has been connected or disconnected.

but the problem im having is the after i send data to the device with this function:


void UsbCom::sendData()
{
mutex->lock();
int r,transf;
r = libusb_interrupt_transfer(devh, EP_INTR_OUT,data, 64,&transf,100);
send = false;
mutex->unlock();
}

and the disconnecting the device gives me a stack smashing error. the callback function that detects if the device has been disconnected:


void ep_irq_in_cb(libusb_transfer *transfer)
{
int *data = static_cast<int*>(transfer->user_data);
if(transfer->status != LIBUSB_TRANSFER_COMPLETED)
{
fprintf(stderr, "uncompleted transter\n");
}
else
{
*data = 1;
}
if (libusb_submit_transfer(transfer) < 0)
{
*data = 2; //device disconnected
}
}

the loop function that uses a switch for *data


void UsbCom::run()
{
int r;
unsigned char temp[64];
r = libusb_init(NULL); //initialize libusb
send = false;
if (r < 0)
{
emit error("Failed to initialize USB!");

}
if (openDevice()) //if device handle can be opened
{
if (detachKernel()) //if kernel driver can be detached
{
if (claimInterface()) //if interface can be claimed
{
//true
int a = 0;
irq_transfer = libusb_alloc_transfer(0);
libusb_fill_interrupt_transfer(irq_transfer, devh, EP_INTR_IN, irqbuf,sizeof(irqbuf), ep_irq_in_cb, &a,10);
libusb_submit_transfer(irq_transfer);
emit error("2");
while(1)
{
if(send)
{
sendData();
}
if (a == 1)
{
for (int i = 0; i<128; i++)
{
temp[i] = irqbuf[i];
}
emit dataRecieved(temp);
a = 0;
}
if (a == 2)
{
break; //device has been disconnected so stop checking for things
}
r = libusb_handle_events(NULL);
}
}
}
emit error("1"); //emit signal to main thread
libusb_close(devh); //close device handle
}
} //stack smashing occurs here


error output:

*** stack smashing detected ***: /home/sisco/Desktop/release/bin/Project terminated
======= Backtrace: =========
/lib/tls/i686/cmov/libc.so.6(__fortify_fail+0x48)[0xb6d3cda8]
/lib/tls/i686/cmov/libc.so.6(__fortify_fail+0x0)[0xb6d3cd60]
/home/sisco/Desktop/release/bin/Project[0x805e640]
[0x0]

complete error output is in the 2 attachments

i have tried finding the problem reading the code line by line for at least a million times but im pretty new to Qt and c++ so couldn't find anything. can anybody point me in the right direction on how to solve this problem?

thanks,

SIsco

[numbat]

unsigned char temp[64];
...
for (int i = 0; i<128; i++)
{
temp&[i] = irqbuf[i];
}

[sisco]

much love, finnaly found it!

temp was only 64 long while irqbuff was 128.
this was driving me crazy, i cant believe i didnt see that =/