DCHECK failed: !src.IsKeySaved()

[securityguru]

uname -a:
Linux HOST 3.2.0-4-amd64 #1 SMP Debian 3.2.54-2 x86_64 GNU/Linux
nginx version: nginx/1.4.7
built by gcc 4.7.2 (Debian 4.7.2-5)
TLS SNI support enabled
configure arguments: --prefix=/usr --conf-path=/etc/nginx/nginx.conf --error-log-path=/var/log/nginx/error.log --http-client-body-temp-path=/var/lib/nginx/body --http-fastcgi-temp-path=/var/lib/nginx/fastcgi --http-log-path=/var/log/nginx/access.log --http-proxy-temp-path=/var/lib/nginx/proxy --http-scgi-temp-path=/var/lib/nginx/scgi --http-uwsgi-temp-path=/var/lib/nginx/uwsgi --lock-path=/var/lock/nginx.lock --pid-path=/var/run/nginx.pid --with-pcre-jit --with-debug --with-http_addition_module --with-http_dav_module --with-http_gzip_static_module --with-http_image_filter_module --with-http_realip_module --with-http_stub_status_module --with-http_ssl_module --with-http_sub_module --with-ipv6 --with-sha1=/usr/include/openssl --with-md5=/usr/include/openssl --with-mail --with-mail_ssl_module --add-module=/root/ngx_pagespeed-release-1.7.30.4-beta

[alert] 29626#0: [ngx_pagespeed 1.7.30.4-3847] [0428/115223:FATAL:string_multi_map.h(243)] Check failed: !src.IsKeySaved().
Backtrace:
        nginx: worker process() [0x4ad627]
        nginx: worker process() [0x4aa7c7]
        nginx: worker process() [0x52fd51]
        nginx: worker process() [0x52fead]
        nginx: worker process() [0x5304bd]
        nginx: worker process() [0x53059f]
        nginx: worker process() [0x530704]
        nginx: worker process() [0x53082d]
        nginx: worker process() [0x5315c6]
        nginx: worker process() [0x52d9d2]
        nginx: worker process() [0x592dd8]
        nginx: worker process() [0x49c541]
        nginx: worker process() [0x49ef06]
        nginx: worker process() [0x49f001]
        nginx: worker process() [0x43af93]
        nginx: worker process() [0x43b0a2]
        nginx: worker process() [0x4465f1]
        nginx: worker process() [0x446c2e]
        nginx: worker process() [0x4471a3]
        nginx: worker process() [0x44776c]
        nginx: worker process() [0x4292d8]
        nginx: worker process() [0x428e4a]
        nginx: worker process() [0x430140]
        nginx: worker process() [0x42e88b]
        nginx: worker process() [0x42f588]
        nginx: worker process() [0x4309f5]
        nginx: worker process() [0x411da6]
        /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xfd) [0x7fa4bb95eead]
        nginx: worker process() [0x410a89]

[oschaaf]

@securityguru
Was this a one-time failure? Or can you reproduce it? If so, would you be able to configure nginx --with-debug and post a backtrace using an nginx build with that?

[securityguru]

It was 14 times per day. I don't know how can I reproduce it, but I build nginx --with-debug and if it fails again I'll post backtrace

[oschaaf]

That would be great! Thanks!

[jeffkaufman]

This is actually fixed on PSOL trunk with r3671, and will be in the 1.8 release.

The problem is that:

bool IsKeySaved() const {
     return key_storage_.data() == key_.data();
}

Is not guaranteed to work if the key is empty.

This was a DCHECK only problem, which means building without --with-debug should avoid it. (Strangely enough.)