Xin Long 25613580a5 xfrm: fix a warning in xfrm_policy_insert_list
commit ed17b8d377 upstream.

This waring can be triggered simply by:

  # ip xfrm policy update src 192.168.1.1/24 dst 192.168.1.2/24 dir in \
    priority 1 mark 0 mask 0x10  #[1]
  # ip xfrm policy update src 192.168.1.1/24 dst 192.168.1.2/24 dir in \
    priority 2 mark 0 mask 0x1   #[2]
  # ip xfrm policy update src 192.168.1.1/24 dst 192.168.1.2/24 dir in \
    priority 2 mark 0 mask 0x10  #[3]

Then dmesg shows:

  [ ] WARNING: CPU: 1 PID: 7265 at net/xfrm/xfrm_policy.c:1548
  [ ] RIP: 0010:xfrm_policy_insert_list+0x2f2/0x1030
  [ ] Call Trace:
  [ ]  xfrm_policy_inexact_insert+0x85/0xe50
  [ ]  xfrm_policy_insert+0x4ba/0x680
  [ ]  xfrm_add_policy+0x246/0x4d0
  [ ]  xfrm_user_rcv_msg+0x331/0x5c0
  [ ]  netlink_rcv_skb+0x121/0x350
  [ ]  xfrm_netlink_rcv+0x66/0x80
  [ ]  netlink_unicast+0x439/0x630
  [ ]  netlink_sendmsg+0x714/0xbf0
  [ ]  sock_sendmsg+0xe2/0x110

The issue was introduced by Commit 7cb8a93968 ("xfrm: Allow inserting
policies with matching mark and different priorities"). After that, the
policies [1] and [2] would be able to be added with different priorities.

However, policy [3] will actually match both [1] and [2]. Policy [1]
was matched due to the 1st 'return true' in xfrm_policy_mark_match(),
and policy [2] was matched due to the 2nd 'return true' in there. It
caused WARN_ON() in xfrm_policy_insert_list().

This patch is to fix it by only (the same value and priority) as the
same policy in xfrm_policy_mark_match().

Thanks to Yuehaibing, we could make this fix better.

v1->v2:
  - check policy->mark.v == pol->mark.v only without mask.

Fixes: 7cb8a93968 ("xfrm: Allow inserting policies with matching mark and different priorities")
Reported-by: Xiumei Mu <xmu@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-06-03 08:21:33 +02:00
2020-06-03 08:21:15 +02:00
2020-05-27 17:46:53 +02:00

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.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%