28.6.1 pipelining crash

[pmuser2]

I wanted to open a site in LAN with NTLM authentication in Palemoon, added the domain to network.automatic-ntlm-auth.trusted-uris.

Palemoon crashes opening specific page of that site.
Windows version: 10, 1903. Windows event log data:

Faulting application name: palemoon.exe, version: 4.3.0.7143, time stamp: 0x5d372a42
Faulting module name: xul.dll, version: 4.3.0.7143, time stamp: 0x5d372c31
Exception code: 0xc0000005
Fault offset: 0x00000000004eca84 (usually, sometimes 0x00000000004e10c4)

[Moonchild]

Please provide a crash dump of this, since I won't be able to recreate the specific crash circumstances. Preferably one for each crash offset seen.

[pmuser2]

I tried to open the page without NTLM, manually entering username and password — Palemoon still crashes.
Crash dump attached.

[Moonchild]

Thanks.

I don't see how this crash can happen. It occurs in the http pipelining part; the connection is yanked out from under us while trying to push data to it. This can happen with bad behaving proxies but we already specifically check for that in our code before trying to continue...

Are you using non-default settings for http pipelining? Are you using a proxy?

[pmuser2]

No explicit proxy server specified in Palemoon, but most likely there is one in-between.

[Moonchild]

Well, there's no code solution that I can see; it seems that whatever is proxying your traffic (could be endpoint security or what not) is not holding the connection open properly for pipelining and somehow yanks it out right between the connection check and connection use (literally the following instruction).

Please disable pipelining for your use as a workaround.

P.S.: It's not recommended to install Pale Moon in %AppData%/local -- you're taking a risk by having the browser binaries installed in an unprotected location.

[pmuser2]

Yes, disabling pipelining works.
It's interesting that neither Firefox, nor Chrome crash at that page.
Also, no other page I visited makes Palemoon crash with pipelining.

[yami_]

AFAIK both Chrome and Firefox do not support HTTP pipelining.

[therube]

Older did, network.http.pipelining.
AFAIK, it was always considered experimental, never defaulted to 'true', & expected that it might cause issues.

Quantum does not have it.
(Chrome, I wouldn't have a clue.)

[New Tobin Paradigm]

Wasn't pipelining effectively obsoleted by http/2 or am I thinking of SPDY?

[yami_]

IDK about SPDY but HTTP/2 does include a mode of operation similar to pipelining called multiplexing.

[Admin]

Wasn't pipelining effectively obsoleted by http/2 or am I thinking of SPDY?

Pipelining works over plain http. http/2.0 multiplexing is only made available for https. Same with SPDY: https only.

[Moonchild]

AFAIK, it was always considered experimental, never defaulted to 'true', & expected that it might cause issues.

It was never enabled by default in Firefox, but has been enabled by default in Pale Moon for many years. The only "issues" there have ever been have been with proxies that didn't implement it properly (pipelining is an integral part of the HTTP/1.1 standard!), which is why pipelining over proxies (if Pale Moon knows about it, i.e.: it's not a transparent system-wide proxy) has been disabled by default.
Mozilla has always been very afraid about the potential "head of line" issue with pipelining (i.e. a request in the pipeline being slow and blocking what is waiting to be transferred through the same pipeline after it) but in practice, especially with the various rescheduling algorithms in place to make new requests if delayed too much, it's never been a problem.

I do have to wonder though: this crash, does it occur over http or https? If https, then it might be an issue with competing protocols (http/2 vs. pipelining) and it might be an idea to disable ssl pipelining with alternative request grouping being commonplace now with http/2...

[pmuser2]

That page's and all its resources' URIs have HTTP scheme, not HTTPS.

[Moonchild]

OK, then what I wondered about is not the case and you're likely dealing with a misbehaving transparent proxy in your environment causing the crash.