8cc8877385
Fix missing dst_release() when local broadcast or multicast traffic is
xfrm policy blocked.
For IPv4 this results to dst leak: ip_route_output_flow() allocates
dst_entry via __ip_route_output_key() and passes it to
xfrm_lookup_route(). xfrm_lookup returns ERR_PTR(-EPERM) that is
propagated. The dst that was allocated is never released.
IPv4 local broadcast testcase:
ping -b 192.168.1.255 &
sleep 1
ip xfrm policy add src 0.0.0.0/0 dst 192.168.1.255/32 dir out action block
IPv4 multicast testcase:
ping 224.0.0.1 &
sleep 1
ip xfrm policy add src 0.0.0.0/0 dst 224.0.0.1/32 dir out action block
For IPv6 the missing dst_release() causes trouble e.g. when used in netns:
ip netns add TEST
ip netns exec TEST ip link set lo up
ip link add dummy0 type dummy
ip link set dev dummy0 netns TEST
ip netns exec TEST ip addr add fd00::1111 dev dummy0
ip netns exec TEST ip link set dummy0 up
ip netns exec TEST ping -6 -c 5 ff02::1%dummy0 &
sleep 1
ip netns exec TEST ip xfrm policy add src ::/0 dst ff02::1 dir out action block
wait
ip netns del TEST
After netns deletion we see:
[ 258.239097] unregister_netdevice: waiting for lo to become free. Usage count = 2
[ 268.279061] unregister_netdevice: waiting for lo to become free. Usage count = 2
[ 278.367018] unregister_netdevice: waiting for lo to become free. Usage count = 2
[ 288.375259] unregister_netdevice: waiting for lo to become free. Usage count = 2
Fixes:
|
||
|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.
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.