tree afe76c2924df428ce363ebf0b09f321961e04bc8
parent e372004b2528c1535e0f51144d68461250d4caaf
author Eric Dumazet <edumazet@google.com> 1602787320 -0700
committer Luca Weiss <luca.weiss@fairphone.com> 1626347892 +0200

icmp: randomize the global rate limiter

[ Upstream commit b38e7819cae946e2edf869e604af1e65a5d241c5 ]

Keyu Man reported that the ICMP rate limiter could be used
by attackers to get useful signal. Details will be provided
in an upcoming academic publication.

Our solution is to add some noise, so that the attackers
no longer can get help from the predictable token bucket limiter.

Fixes: 4cdf507d5452 ("icmp: add a global rate limitation")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Keyu Man <kman001@ucr.edu>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit df838165a187b7c699ec372a2a136f9873112776)