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author | Josh Boyer <jwboyer@fedoraproject.org> | 2016-07-25 09:05:30 -0400 |
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committer | Josh Boyer <jwboyer@fedoraproject.org> | 2016-07-25 09:05:58 -0400 |
commit | d0b2d44c4fce37700766991fdc9eb1e4d0415231 (patch) | |
tree | 8df2616e1ac43fc9ea126893db09a15a4803ffbd | |
parent | 539770f69f7ab602dfd94830fa9c8f0e64122d8e (diff) | |
download | kernel-d0b2d44c4fce37700766991fdc9eb1e4d0415231.tar.gz kernel-d0b2d44c4fce37700766991fdc9eb1e4d0415231.tar.xz kernel-d0b2d44c4fce37700766991fdc9eb1e4d0415231.zip |
Add second patch needed to fix CVE-2016-5696
-rw-r--r-- | kernel.spec | 1 | ||||
-rw-r--r-- | tcp-enable-per-socket-rate-limiting-of-all-challenge.patch | 102 |
2 files changed, 103 insertions, 0 deletions
diff --git a/kernel.spec b/kernel.spec index b1c130b19..805ad3fa2 100644 --- a/kernel.spec +++ b/kernel.spec @@ -669,6 +669,7 @@ Patch834: qla2xxx-Fix-NULL-pointer-deref-in-QLA-interrupt.patch #CVE-2016-5389 CVE-2016-5969 rhbz 1354708 1355615 Patch835: tcp-make-challenge-acks-less-predictable.patch +Patch839: tcp-enable-per-socket-rate-limiting-of-all-challenge.patch # https://lists.fedoraproject.org/archives/list/kernel@lists.fedoraproject.org/message/A4YCP7OGMX6JLFT5V44H57GOMAQLC3M4/ Patch836: drm-amdgpu-Disable-RPM-helpers-while-reprobing.patch diff --git a/tcp-enable-per-socket-rate-limiting-of-all-challenge.patch b/tcp-enable-per-socket-rate-limiting-of-all-challenge.patch new file mode 100644 index 000000000..0a5eab8aa --- /dev/null +++ b/tcp-enable-per-socket-rate-limiting-of-all-challenge.patch @@ -0,0 +1,102 @@ +From 8272c58d085e5611a7f839fa32e148ae62446375 Mon Sep 17 00:00:00 2001 +From: Jason Baron <jbaron@akamai.com> +Date: Thu, 14 Jul 2016 11:38:40 -0400 +Subject: [PATCH] tcp: enable per-socket rate limiting of all 'challenge acks' + +The per-socket rate limit for 'challenge acks' was introduced in the +context of limiting ack loops: + +commit f2b2c582e824 ("tcp: mitigate ACK loops for connections as tcp_sock") + +And I think it can be extended to rate limit all 'challenge acks' on a +per-socket basis. + +Since we have the global tcp_challenge_ack_limit, this patch allows for +tcp_challenge_ack_limit to be set to a large value and effectively rely on +the per-socket limit, or set tcp_challenge_ack_limit to a lower value and +still prevents a single connections from consuming the entire challenge ack +quota. + +It further moves in the direction of eliminating the global limit at some +point, as Eric Dumazet has suggested. This a follow-up to: +Subject: tcp: make challenge acks less predictable + +Cc: Eric Dumazet <edumazet@google.com> +Cc: David S. Miller <davem@davemloft.net> +Cc: Neal Cardwell <ncardwell@google.com> +Cc: Yuchung Cheng <ycheng@google.com> +Cc: Yue Cao <ycao009@ucr.edu> +Signed-off-by: Jason Baron <jbaron@akamai.com> +Signed-off-by: David S. Miller <davem@davemloft.net> +--- + net/ipv4/tcp_input.c | 39 ++++++++++++++++++++++----------------- + 1 file changed, 22 insertions(+), 17 deletions(-) + +diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c +index 8c011359646b..796315104ad7 100644 +--- a/net/ipv4/tcp_input.c ++++ b/net/ipv4/tcp_input.c +@@ -3423,6 +3423,23 @@ static int tcp_ack_update_window(struct sock *sk, const struct sk_buff *skb, u32 + return flag; + } + ++static bool __tcp_oow_rate_limited(struct net *net, int mib_idx, ++ u32 *last_oow_ack_time) ++{ ++ if (*last_oow_ack_time) { ++ s32 elapsed = (s32)(tcp_time_stamp - *last_oow_ack_time); ++ ++ if (0 <= elapsed && elapsed < sysctl_tcp_invalid_ratelimit) { ++ NET_INC_STATS(net, mib_idx); ++ return true; /* rate-limited: don't send yet! */ ++ } ++ } ++ ++ *last_oow_ack_time = tcp_time_stamp; ++ ++ return false; /* not rate-limited: go ahead, send dupack now! */ ++} ++ + /* Return true if we're currently rate-limiting out-of-window ACKs and + * thus shouldn't send a dupack right now. We rate-limit dupacks in + * response to out-of-window SYNs or ACKs to mitigate ACK loops or DoS +@@ -3436,21 +3453,9 @@ bool tcp_oow_rate_limited(struct net *net, const struct sk_buff *skb, + /* Data packets without SYNs are not likely part of an ACK loop. */ + if ((TCP_SKB_CB(skb)->seq != TCP_SKB_CB(skb)->end_seq) && + !tcp_hdr(skb)->syn) +- goto not_rate_limited; +- +- if (*last_oow_ack_time) { +- s32 elapsed = (s32)(tcp_time_stamp - *last_oow_ack_time); +- +- if (0 <= elapsed && elapsed < sysctl_tcp_invalid_ratelimit) { +- NET_INC_STATS_BH(net, mib_idx); +- return true; /* rate-limited: don't send yet! */ +- } +- } +- +- *last_oow_ack_time = tcp_time_stamp; ++ return false; + +-not_rate_limited: +- return false; /* not rate-limited: go ahead, send dupack now! */ ++ return __tcp_oow_rate_limited(net, mib_idx, last_oow_ack_time); + } + + /* RFC 5961 7 [ACK Throttling] */ +@@ -3463,9 +3468,9 @@ static void tcp_send_challenge_ack(struct sock *sk, const struct sk_buff *skb) + u32 count, now; + + /* First check our per-socket dupack rate limit. */ +- if (tcp_oow_rate_limited(sock_net(sk), skb, +- LINUX_MIB_TCPACKSKIPPEDCHALLENGE, +- &tp->last_oow_ack_time)) ++ if (__tcp_oow_rate_limited(sock_net(sk), ++ LINUX_MIB_TCPACKSKIPPEDCHALLENGE, ++ &tp->last_oow_ack_time)) + return; + + /* Then check host-wide RFC 5961 rate limit. */ +-- +2.7.4 + |