tree 3ce5d5c7dfcbe5770e49c898ce2e4271698e7aa8
parent 467d4d2c6d3c2057f8ea1a8eba782c62bbb89d08
author Eric Dumazet <edumazet@google.com> 1602787320 -0700
committer Todd Kjos <tkjos@google.com> 1617397855 -0700

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>