diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-11-30 03:37:57 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-12-03 04:37:16 (GMT) |
| commit | 45f6fad84cc305103b28d73482b344d7f5b76f39 (patch) | |
| tree | 283dbc3a6cd4a26288a3526d0de48cf8c2e27b75 /net/ipv6/syncookies.c | |
| parent | 01b3f52157ff5a47d6d8d796f396a4b34a53c61d (diff) | |
| download | linux-45f6fad84cc305103b28d73482b344d7f5b76f39.tar.xz | |
ipv6: add complete rcu protection around np->opt
This patch addresses multiple problems :
UDP/RAW sendmsg() need to get a stable struct ipv6_txoptions
while socket is not locked : Other threads can change np->opt
concurrently. Dmitry posted a syzkaller
(http://github.com/google/syzkaller) program desmonstrating
use-after-free.
Starting with TCP/DCCP lockless listeners, tcp_v6_syn_recv_sock()
and dccp_v6_request_recv_sock() also need to use RCU protection
to dereference np->opt once (before calling ipv6_dup_options())
This patch adds full RCU protection to np->opt
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/syncookies.c')
| -rw-r--r-- | net/ipv6/syncookies.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv6/syncookies.c b/net/ipv6/syncookies.c index bb8f2fa..eaf7ac4 100644 --- a/net/ipv6/syncookies.c +++ b/net/ipv6/syncookies.c @@ -222,7 +222,7 @@ struct sock *cookie_v6_check(struct sock *sk, struct sk_buff *skb) memset(&fl6, 0, sizeof(fl6)); fl6.flowi6_proto = IPPROTO_TCP; fl6.daddr = ireq->ir_v6_rmt_addr; - final_p = fl6_update_dst(&fl6, np->opt, &final); + final_p = fl6_update_dst(&fl6, rcu_dereference(np->opt), &final); fl6.saddr = ireq->ir_v6_loc_addr; fl6.flowi6_oif = sk->sk_bound_dev_if; fl6.flowi6_mark = ireq->ir_mark; |