Florian Westphal 3819a35fdb xfrm: fix possible null deref in xfrm_init_tempstate
Dan reports following smatch warning:
 net/xfrm/xfrm_state.c:659
 error: we previously assumed 'afinfo' could be null (see line 651)

 649  struct xfrm_state_afinfo *afinfo = xfrm_state_afinfo_get_rcu(family);
 651  if (afinfo)
		...
 658  }
 659  afinfo->init_temprop(x, tmpl, daddr, saddr);

I am resonably sure afinfo cannot be NULL here.

xfrm_state4.c and state6.c are both part of ipv4/ipv6 (depends on
CONFIG_XFRM, a boolean) but even if ipv6 is a module state6.c can't
be removed (ipv6 lacks module_exit so it cannot be removed).

The only callers for xfrm6_fini that leads to state backend unregister
are error unwinding paths that can be called during ipv6 init function.

So after ipv6 module is loaded successfully the state backend cannot go
away anymore.

The family value from policy lookup path is taken from dst_entry, so
that should always be AF_INET(6).

However, since this silences the warning and avoids readers of this
code wondering about possible null deref it seems preferrable to
be defensive and just add the old check back.

Fixes: 711059b975 ("xfrm: add and use xfrm_state_afinfo_get_rcu")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2017-01-16 08:36:33 +01:00
2016-12-25 17:21:22 +01:00
2016-12-25 17:21:23 +01:00
2016-12-26 17:30:24 -08:00
2016-12-25 17:21:22 +01:00
2016-05-23 17:04:14 -07:00
2016-12-25 16:13:08 -08:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

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.
Description
No description provided
Readme 3.4 GiB
Languages
C 97%
Assembly 1%
Shell 0.6%
Rust 0.5%
Python 0.4%
Other 0.3%