nginx 1.17.9-1~bionic - 400 error

[Maxim Dounin]

Hello!

On Wed, Mar 04, 2020 at 08:54:49PM +0100, roland-brieden at web.de wrote:

>    Hey Guys.
>    After todays update to nginx 1.17.9-1~bionic all my websites crashes
>    into 400 error.
>    Going back to nginx 1.17.8-1~bionic and all websites works ok.
>    What can i do?

First of all, check your error logs.  The reason for any 400 error 
returned by nginx is logged into error log at the "info" level.

Note though that the "info" level is below the default logging 
level, so you may need to adjust your configuration to see 
relevant errors.  See http://nginx.org/r/error_log for details.

The most likely reason is that 400 errors you see are somehow 
related to duplicate Host or Transfer-Encoding, as outlined in 
CHANGES:

    *) Change: now nginx does not allow several "Host" request header lines.

    *) Bugfix: nginx ignored additional "Transfer-Encoding" request header
       lines.

Probably in your configuration requests with duplicate headers are 
generated somehow, leading to 400.

Just in case, relevant commits are:

http://hg.nginx.org/nginx/rev/aca005d232ff
http://hg.nginx.org/nginx/rev/fe5976aae0e3
http://hg.nginx.org/nginx/rev/4f18393a1d51

-- 
Maxim Dounin
http://mdounin.ru/