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
..
acpi	ACPI updates for 5.4-rc1	2019-09-17 19:31:36 -07:00
asm-generic	Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security	2019-09-28 08:14:15 -07:00
clocksource
crypto	Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity	2019-09-27 19:37:27 -07:00
drm	drm: Measure Self Refresh Entry/Exit times to avoid thrashing	2019-09-19 10:03:32 -04:00
dt-bindings	Main MIPS changes for v5.4:	2019-09-22 09:30:30 -07:00
keys
kvm
linux	net/flow_dissector: switch to siphash	2019-10-23 20:13:22 -07:00
math-emu	nds32: Mark expected switch fall-throughs	2019-08-29 11:06:56 -05:00
media
misc
net	net/flow_dissector: switch to siphash	2019-10-23 20:13:22 -07:00
pcmcia
ras
rdma	RDMA subsystem updates for 5.4	2019-09-21 10:26:24 -07:00
scsi	SCSI fixes on 20191015	2019-10-15 12:19:08 -07:00
soc	Char/Misc driver patches for 5.4-rc1	2019-09-18 11:14:31 -07:00
sound	ALSA: hdac: clear link output stream mapping	2019-10-07 03:58:48 +02:00
target
trace	tcp: annotate sk->sk_wmem_queued lockless reads	2019-10-13 10:13:08 -07:00
uapi	TTY/Serial driver fixes for 5.4-rc3	2019-10-12 15:42:19 -07:00
vdso
video
xen	xen: fixes and cleanups for 5.4-rc2	2019-10-04 11:13:09 -07:00
Kbuild	- New Drivers	2019-09-23 19:37:49 -07:00