I have the dmp file mentioned, but I don't know how to attach it to the issue.
You need to upload the dump to a site where it can be downloaded. However, this is the Out of Memory bug located at #813.
Please post this information, as well as the dmp there.
Closing this one as a duplicate of #813.
The fact that this dump mentions that you lost internet connectivity (but not network) may be part of the issue the rest of us are facing over there.
Nothing extracted yet.
I believe that Steam was in the process of downloading an update for one of my games when I lost my connection to the internet (the OS still reported being connected to the wireless network, but I was unable to ping any external server, even 8.8.8.8). The Steam client crashed with the following output:
UT OF MEMORY! attempted allocation size: 1689600 ****
memstd.cpp (2501) : Assertion Failed: OUT OF MEMORY
memstd.cpp (2501) : Fatal assert failed: /home/buildbot/buildslave_steam/steam_rel_client_ubuntu12_linux/build/src/tier0/memstd.cpp, line 2501. Application exiting.
Assert( Fatal assert ):/home/buildbot/buildslave_steam/steam_rel_client_ubuntu12_linux/build/src/tier0/memstd.cpp:2501
Installing breakpad exception handler for appid(steam)/version(1361807486_client)
Uploading dump (in-process) [proxy '']
/tmp/dumps/assert_20130303105803_1.dmp
success = no
error: Couldn't resolve host name
_ExitOnFatalAssert