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Filename Latest commit message Latest commit date
Eric Dumazet 55667441c8 net/flow_dissector: switch to siphash
UDP IPv6 packets auto flowlabels are using a 32bit secret
(static u32 hashrnd in net/core/flow_dissector.c) and
apply jhash() over fields known by the receivers.

Attackers can easily infer the 32bit secret and use this information
to identify a device and/or user, since this 32bit secret is only
set at boot time.

Really, using jhash() to generate cookies sent on the wire
is a serious security concern.

Trying to change the rol32(hash, 16) in ip6_make_flowlabel() would be
a dead end. Trying to periodically change the secret (like in sch_sfq.c)
could change paths taken in the network for long lived flows.

Let's switch to siphash, as we did in commit df453700e8
("inet: switch IP ID generator to siphash")

Using a cryptographically strong pseudo random function will solve this
privacy issue and more generally remove other weak points in the stack.

Packet schedulers using skb_get_hash_perturb() benefit from this change.

Fixes: b56774163f ("ipv6: Enable auto flow labels by default")
Fixes: 42240901f7 ("ipv6: Implement different admin modes for automatic flow labels")
Fixes: 67800f9b1f ("ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel")
Fixes: cb1ce2ef38 ("ipv6: Implement automatic flow label generation on transmit")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jonathan Berger <jonathann1@walla.com>
Reported-by: Amit Klein <aksecurity@gmail.com>
Reported-by: Benny Pinkas <benny@pinkas.net>
Cc: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-23 20:13:22 -07:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-19 17:09:11 -04:00
block blk-rq-qos: fix first node deletion of rq_qos_del() 2019-10-15 10:13:13 -06:00
certs
crypto
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-19 17:09:11 -04:00
drivers bnxt_en: Avoid disabling pci device in bnxt_remove_one() for already disabled device. 2019-10-22 13:15:39 -07:00
fs Merge branch 'akpm' (patches from Andrew) 2019-10-19 06:53:59 -04:00
include net/flow_dissector: switch to siphash 2019-10-23 20:13:22 -07:00
init
ipc
kernel kernel/events/uprobes.c: only do FOLL_SPLIT_PMD for uprobe register 2019-10-19 06:32:33 -04:00
lib copy-struct-from-user-v5.4-rc4 2019-10-18 18:19:04 -04:00
LICENSES
mm mm/thp: allow dropping THP from page cache 2019-10-19 06:32:33 -04:00
net net/flow_dissector: switch to siphash 2019-10-23 20:13:22 -07:00
samples
scripts scripts/gdb: fix debugging modules on s390 2019-10-19 06:32:33 -04:00
security selinux/stable-5.4 PR 20191007 2019-10-08 10:51:37 -07:00
sound ALSA: hda - Force runtime PM on Nvidia HDMI codecs 2019-10-17 17:45:32 +02:00
tools selftests: Make l2tp.sh executable 2019-10-22 14:01:35 -07:00
usr
virt
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
Kbuild
Kconfig
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-19 17:09:11 -04:00
Makefile Linux 5.4-rc3 2019-10-13 16:37:36 -07:00
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.

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.