This is a note to let you know that I've just added the patch titled
dccp/tcp: do not inherit mc_list from parent
to the 4.4-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:
dccp-tcp-do-not-inherit-mc_list-from-parent.patch
and it can be found in the queue-4.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From foo@baz Fri Jun 2 09:29:55 JST 2017
From: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Tue, 9 May 2017 06:29:19 -0700
Subject: dccp/tcp: do not inherit mc_list from parent
From: Eric Dumazet <edumazet@xxxxxxxxxx>
[ Upstream commit 657831ffc38e30092a2d5f03d385d710eb88b09a ]
syzkaller found a way to trigger double frees from ip_mc_drop_socket()
It turns out that leave a copy of parent mc_list at accept() time,
which is very bad.
Very similar to commit 8b485ce69876 ("tcp: do not inherit
fastopen_req from parent")
Initial report from Pray3r, completed by Andrey one.
Thanks a lot to them !
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Reported-by: Pray3r <pray3r.z@xxxxxxxxx>
Reported-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Tested-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv4/inet_connection_sock.c | 2 ++
1 file changed, 2 insertions(+)
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -669,6 +669,8 @@ struct sock *inet_csk_clone_lock(const s
inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num);
newsk->sk_write_space = sk_stream_write_space;
+ inet_sk(newsk)->mc_list = NULL;
+
newsk->sk_mark = inet_rsk(req)->ir_mark;
atomic64_set(&newsk->sk_cookie,
atomic64_read(&inet_rsk(req)->ir_cookie));
Patches currently in stable-queue which might be from edumazet@xxxxxxxxxx are
queue-4.4/sctp-do-not-inherit-ipv6_-mc-ac-fl-_list-from-parent.patch
queue-4.4/tcp-avoid-fastopen-api-to-be-used-on-af_unspec.patch
queue-4.4/tcp-eliminate-negative-reordering-in-tcp_clean_rtx_queue.patch
queue-4.4/netem-fix-skb_orphan_partial.patch
queue-4.4/dccp-tcp-do-not-inherit-mc_list-from-parent.patch
queue-4.4/tcp-avoid-fragmenting-peculiar-skbs-in-sack.patch
queue-4.4/ipv6-dccp-do-not-inherit-ipv6_mc_list-from-parent.patch
queue-4.4/ipv6-fix-out-of-bound-writes-in-__ip6_append_data.patch
queue-4.4/ipv4-add-reference-counting-to-metrics.patch