From James Morris:
There's a bug in the seqfile handling for /proc/net/ip6_flowlabel, where, after
finding a flowlabel, the code will loop forever not finding any further
flowlabels, first traversing the rest of the hash bucket then just looping. This
bug can cause lockups and oopses, and is trivially invoked by an unpriveleged user.
committed in stream U5 build 42.30. A test kernel with this patch is available
committed in stream E5 build 42.0.4
verified using the attached test case.
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.