This is a note to let you know that I've just added the patch titled netfilter: ip6_tables: zero-initialize fragment offset to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: netfilter-ip6_tables-zero-initialize-fragment-offset.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 31fb6efeb3cd516524cf1f5154a24fa2a3312dd8 Author: Jeremy Sowden <jeremy@xxxxxxxxxx> Date: Sun Sep 12 22:24:33 2021 +0100 netfilter: ip6_tables: zero-initialize fragment offset [ Upstream commit 310e2d43c3ad429c1fba4b175806cf1f55ed73a6 ] ip6tables only sets the `IP6T_F_PROTO` flag on a rule if a protocol is specified (`-p tcp`, for example). However, if the flag is not set, `ip6_packet_match` doesn't call `ipv6_find_hdr` for the skb, in which case the fragment offset is left uninitialized and a garbage value is passed to each matcher. Signed-off-by: Jeremy Sowden <jeremy@xxxxxxxxxx> Reviewed-by: Florian Westphal <fw@xxxxxxxxx> Signed-off-by: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/ipv6/netfilter/ip6_tables.c b/net/ipv6/netfilter/ip6_tables.c index 579fda1bc45d..ce54e66b47a0 100644 --- a/net/ipv6/netfilter/ip6_tables.c +++ b/net/ipv6/netfilter/ip6_tables.c @@ -290,6 +290,7 @@ ip6t_do_table(struct sk_buff *skb, * things we don't know, ie. tcp syn flag or ports). If the * rule is also a fragment-specific rule, non-fragments won't * match it. */ + acpar.fragoff = 0; acpar.hotdrop = false; acpar.net = state->net; acpar.in = state->in;