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Issue 875207 link

Starred by 2 users

Issue metadata

Status: Duplicate
Merged: issue 861550
Owner:
Closed: Sep 26
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: Windows
Pri: 2
Type: Bug



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endless loop when viewing PDF files via slow 3G connection

Reported by craig.fo...@googlemail.com, Aug 17

Issue description

UserAgent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.75 Safari/537.36

Example URL:
Any URL with a PDF

Steps to reproduce the problem:
1. Open PDF file URL (it loads)
2. Press F12 -> Network -> slow 3g
3. delete cache
4. Reload PDF file

What is the expected behavior?
Downloading the PDF file and then stopping requests.

What went wrong?
GET /my.pdf HTTP/1.1
Host: myhost
Connection: keep-alive
DNT: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36
Accept: */*
Referer: http://myhost/my.pdf
Accept-Encoding: gzip, deflate
Accept-Language: de,de-DE;q=0.9,en-US;q=0.8,en;q=0.7,ja;q=0.6
Cookie: CENSORED
Range: bytes=7340032-7984276
If-None-Match: 9c2ada0b4654d89903574231a86bb4da

HTTP/1.1 304 Not Modified
Date: Fri, 17 Aug 2018 11:32:50 GMT
Server: Apache
ETag: 9c2ada0b4654d89903574231a86bb4da
Content-Type: application/pdf;charset=UTF-8
Content-Language: de
X-Cacheable: Yes: Forced
X-Varnish: 229531
Age: 0
Via: 1.1 varnish-v4
X-Grace: none
X-Cache: MISS

GET /my.pdf HTTP/1.1
Host: myhost
Connection: keep-alive
DNT: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36
Accept: */*
Referer: http://mysite/my.pdf
Accept-Encoding: gzip, deflate
Accept-Language: de,de-DE;q=0.9,en-US;q=0.8,en;q=0.7,ja;q=0.6
Cookie: CENSORED
Range: bytes=7340032-7984276

HTTP/1.1 206 Partial Content
Date: Fri, 17 Aug 2018 11:32:50 GMT
Server: Apache
ETag: 9c2ada0b4654d89903574231a86bb4da
Content-Type: application/pdf;charset=UTF-8
Content-Language: de
X-Cacheable: Yes: Forced
X-Varnish: 229533 229532
Age: 0
Via: 1.1 varnish-v4
X-Grace: none
X-Cache: HIT
Accept-Ranges: bytes
Content-Range: bytes 7340032-7984276/7984277
Content-Length: 644245

[...] CONTENT [...]

GET /my.pdf HTTP/1.1
Host: mysite
Connection: keep-alive
DNT: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36
Accept: */*
Referer: http://mysite/my.pdf
Accept-Encoding: gzip, deflate
Accept-Language: de,de-DE;q=0.9,en-US;q=0.8,en;q=0.7,ja;q=0.6
Cookie: CENSORED
Range: bytes=1835008-7340031
If-Range: 9c2ada0b4654d89903574231a86bb4da

HTTP/1.1 206 Partial Content
Date: Fri, 17 Aug 2018 11:32:50 GMT
Server: Apache
ETag: 9c2ada0b4654d89903574231a86bb4da
Content-Type: application/pdf;charset=UTF-8
Content-Language: de
X-Cacheable: Yes: Forced
X-Varnish: 229534 229532
Age: 0
Via: 1.1 varnish-v4
X-Grace: none
X-Cache: HIT
Accept-Ranges: bytes
Content-Range: bytes 1835008-7340031/7984277
Content-Length: 5505024

[...] CONTENT [...]

GET /my.pdf HTTP/1.1
Host: mysite
Connection: keep-alive
DNT: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36
Accept: */*
Referer: http://mysite/my.pdf
Accept-Encoding: gzip, deflate
Accept-Language: de,de-DE;q=0.9,en-US;q=0.8,en;q=0.7,ja;q=0.6
Cookie: CENSORED
Range: bytes=7274496-7340031
If-None-Match: 9c2ada0b4654d89903574231a86bb4da

HTTP/1.1 304 Not Modified
Date: Fri, 17 Aug 2018 11:32:50 GMT
Server: Apache
ETag: 9c2ada0b4654d89903574231a86bb4da
Content-Type: application/pdf;charset=UTF-8
Content-Language: de
X-Cacheable: Yes: Forced
X-Varnish: 229535 229532
Age: 0
Via: 1.1 varnish-v4
X-Grace: none
X-Cache: HIT

GET /my.pdf HTTP/1.1
Host: mysite
Connection: keep-alive
DNT: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/68.0.3440.106 Safari/537.36
Accept: */*
Referer: my.pdf
Accept-Encoding: gzip, deflate
Accept-Language: de,de-DE;q=0.9,en-US;q=0.8,en;q=0.7,ja;q=0.6
Cookie: CENSORED
Range: bytes=7274496-7340031
If-None-Match: 9c2ada0b4654d89903574231a86bb4da

And there's the endless loop, the byte Range never changes, and the client keeps making these requests.
The requests aren't shown in the window, but you can sniff your traffic or look at the serverside logs.
So as long as the PDF is open, the server is getting hammered with requests, sometimes as many as 20-30 per second, it looks just like a Layer 7 DDoS.

I hope this report is sufficient.

Did this work before? N/A 

Chrome version: Chrome/68.0.3440.106  Channel: n/a
OS Version: 10
Flash Version:
 
Cc: morlovich@chromium.org
Any chance you could provide a NetLog as per:
https://www.chromium.org/for-testers/providing-network-details
(It hides cookies by default, but not hostnames)

Components: Internals>Plugins>PDF
Labels: Needs-Triage-M68
chrome-net-export-log.json
19.3 MB Download
Thanks. I am seeing lots of separate URL_REQUEST's for that last range, so it looks like the PDF plugin asking for it repeatedly rather than the cache layer screwing it up on its own.

Cc: thestig@chromium.org
thestig, do you know who is familiar with this part of the PDF plugin?
Cc: phanindra.mandapaka@chromium.org
Labels: Needs-Feedback Triaged-ET
Thanks for filing the issue...

@Reporter : Tried to test the issue but unable to get the URL. It would be really helpful if a sample URL/Extension is provided, so that we can investigate the issue further. If possible provide screen-cast for better triaging it. 

Thanks.!
Components: -Internals>Network
Removing the network label, as this looks to most likely be an issue with the PDF plugin.
We would like to share the problematic pdf where we encountered the problem, so you can reproduce the problem more easily. But we don't want to disclose it publicly.

Can we send it directly to one of your e-mails @chromium.org?

Regards,
Sven
My colleague just told me that the url is already disclosed inside the logfiles, so there is no problem disclosing it here again.

https://www.henkel.de/blob/829906/9c2ada0b4654d89903574231a86bb4da/data/2017-geschaeftsbericht.pdf

Regards,
Sven
Can you see if this issue still exists with Chrome 69?
Seems fixed, can't replicante it, and I don't see the behaviour in serverlogs for Chrome/69 anymore. Thank you!
Project Member

Comment 13 by sheriffbot@chromium.org, Sep 20

Labels: -Needs-Feedback
Thank you for providing more feedback. Adding the requester to the cc list.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot
Owner: thestig@chromium.org
Lei, should we close this? Is it a dupe of the other range request loop bug?
Mergedinto: 861550
Status: Duplicate (was: Unconfirmed)

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