Procfs race condition bug

From: Mike Cardwell
Date: Fri Jul 20 2012 - 14:19:08 EST

I *think* I've uncovered a race condition bug in procfs. If I attempt to
open a file in /proc/net, eg "/proc/net/tcp" it works fine, but if I
spawn a POSIX thread and attempt to do it from there, it *usually* fails
with a "No such file or directory", but some times succeeds. If I do a
system call inside the thread to look up the thread ID and then open
"/proc/THREADID/net/tcp" instead, it works fine.

There are more details and some example code so you can replicate the
problem on a stack overflow question I asked earlier today here:

This is the first time I have attempted to report a (suspected) Linux
kernel bug, so I apologise if I have made any mistakes. I am not
subscribed to the list, so please Cc me in on any responses.


Mike Cardwell
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