oss-sec mailing list archives
Re: Linux kernel ping socket / AF_LLC connect() sin_family race
From: Eric Dumazet <edumazet () google com>
Date: Fri, 24 Mar 2017 15:21:06 -0700
On Fri, Mar 24, 2017 at 1:43 PM, Andrey Konovalov <andreyknvl () google com> wrote:
On Fri, Mar 24, 2017 at 9:27 PM, Solar Designer <solar () openwall com> wrote:Hi, I haven't fully investigated this issue, and the Subject is provisional (but will probably get stuck). I am not yet sure which kernel subsystem(s) to blame here (ping sockets? LLC sockets? other/more?), and there might be other ways to trigger the issue.Reproduced the crash on current upstream (ebe64824e9de4b3ab3bd3928312b4b2bc57b4b7e). Adding kernel maintainers.
Looks easy enough to fix ? diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index 2af6244b83e27ae384e96cf071c10c5a89674804..ccfbce13a6333a65dab64e4847dd510dfafb1b43 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -156,17 +156,18 @@ int ping_hash(struct sock *sk) void ping_unhash(struct sock *sk) { struct inet_sock *isk = inet_sk(sk); + pr_debug("ping_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num); + write_lock_bh(&ping_table.lock); if (sk_hashed(sk)) { - write_lock_bh(&ping_table.lock); hlist_nulls_del(&sk->sk_nulls_node); sk_nulls_node_init(&sk->sk_nulls_node); sock_put(sk); isk->inet_num = 0; isk->inet_sport = 0; sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1); - write_unlock_bh(&ping_table.lock); } + write_unlock_bh(&ping_table.lock); } EXPORT_SYMBOL_GPL(ping_unhash);
Current thread:
- Linux kernel ping socket / AF_LLC connect() sin_family race Solar Designer (Mar 24)
- Re: Linux kernel ping socket / AF_LLC connect() sin_family race Andrey Konovalov (Mar 24)
- Re: Linux kernel ping socket / AF_LLC connect() sin_family race Eric Dumazet (Mar 24)
- Re: Linux kernel ping socket / AF_LLC connect() sin_family race Solar Designer (Mar 24)
- Re: Linux kernel ping socket / AF_LLC connect() sin_family race Eric Dumazet (Mar 24)
- Re: Linux kernel ping socket / AF_LLC connect() sin_family race Andrey Konovalov (Mar 24)