Re: crash when ICAPModXact::parseHead throws

On Tue, 2006-10-24 at 07:55 +0200, Gernot Tenchio wrote:

> I see random crashes because ICAPModXact::parseHead throws an
> exception. This always happens if there are no headers to parse at all
> (maybe because of a bug on the server side).
>
> #11 0x08113ce9 in __cxa_throw ()
> #12 0x0813ca7f in Throw ()
> #13 0x0813f435 in ICAPModXact::parseHead ()
> #14 0x08141f5e in ICAPModXact::parseIcapHead ()
> #15 0x0814229a in ICAPModXact::parseHeaders ()
> #16 0x08142675 in ICAPModXact::parseMore ()
> #17 0x081427ae in ICAPModXact::handleCommRead ()
> #18 0x08146161 in ICAPXaction::noteCommRead ()
> #19 0x081462cd in ICAPXaction_noteCommRead ()
> #20 0x080ed2cc in commio_call_callback ()
> #21 0x080ed318 in commio_call_callbacks ()
> #22 0x080efa19 in CommDispatcher::dispatch ()
> #23 0x0808b815 in EventLoop::runOnce ()
> #24 0x0808b941 in EventLoop::run ()
> #25 0x080bd877 in main ()

Throwing in exception is expected under exceptional conditions such as a
parsing failure. The exception should be caught by noteCommRead,
terminating the ICAP transaction. I have just tested it by throwing an
exception unconditionally in parseHead, and it seems to work: The ICAP
transaction terminates and the HTTP client gets an "ICAP protocol error"
response from Squid.

This is all with squid3-icap branch. I have not tested with HEAD and
would not be surprised if terminated ICAP transactions are not handled
well there.

If you can reproduce with squid3-icap, please note that the above stack
trace is missing the first 11 frames. You said that Squid crashes. How
does it crash? What compiler are you using?

Thank you,

Alex.
Received on Tue Oct 24 2006 - 08:13:17 MDT