Created attachment 149261 [details]
Stack trace found while attempting to connect without 11n_disable

I attend a major university which authenticates to WiFi via WPA2-Enterprise. Oftentimes, it is found that in large auditoriums that have many APs in a small space, Linux-based laptops have issues associating with the network, soliciting a DHCP lease, or once connected, making any outgoing TCP connections. This bug is being reported here because we believe that there is potentially a bug somewhere in the Linux wireless stack, rather than a bug in wpa_supplicant or DHCP client software (we are able to connect to access points on the same network in different locations with identical configurations).

Some details:
Wireless hardware: Problem confirmed on Intel Centrino-N 1000, Intel Advanced-N 6200 2.4/5GHz, Intel Dual-Band Wireless-AC 7260
Distros: archlinux, Ubuntu (including with mainline kernels), Fedora, etc.
Frequency of problem: always
Locations of problem: only in high density areas (200+ person lecture halls) that have multiple access points in a confined space -- never in smaller density areas

A workaround was found by reloading the iwlwifi module with 11n_disable=1. This almost always (at a significant performance cost) allows us to associate to the network, solicit an IP address, and otherwise make outgoing connections without trouble. Because the workaround exists at the driver level, we believe that the issue is in Linux itself.

We can provide additional information from our devices as well as some information from our IT department as necessary.