Florian Westphal
1548bc4e05
An xfrm hash rebuild has to reset the inexact policy list before the
policies get re-inserted: A change of hash thresholds will result in
policies to get moved from inexact tree to the policy hash table.
If the thresholds are increased again later, they get moved from hash
table to inexact tree.
We must unlink all policies from the inexact tree before re-insertion.
Otherwise 'migrate' may find policies that are in main hash table a
second time, when it searches the inexact lists.
Furthermore, re-insertion without deletion can cause elements ->next to
point back to itself, causing soft lockups or double-frees.
Reported-by: syzbot+9d971dd21eb26567036b@syzkaller.appspotmail.com
Fixes: 9cf545ebd5 ("xfrm: policy: store inexact policies in a tree ordered by destination address")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.