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authorDavid S. Miller <davem@davemloft.net>2019-06-18 20:48:45 -0400
committerDavid S. Miller <davem@davemloft.net>2019-06-18 20:48:45 -0400
commit55458d2f4074307c2aa787300c9272ff668a3ac3 (patch)
tree03d9bfdcebf70b57817c69008433de9e53c01e61
parent72b319dc08b4924a29f5e2560ef6d966fa54c429 (diff)
parentc3bcde026684c62d7a2b6f626dc7cf763833875c (diff)
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Merge branch 'net-fix-quite-a-few-dst_cache-crashes-reported-by-syzbot'
Xin Long says: ==================== net: fix quite a few dst_cache crashes reported by syzbot There are two kinds of crashes reported many times by syzbot with no reproducer. Call Traces are like: BUG: KASAN: slab-out-of-bounds in rt_cache_valid+0x158/0x190 net/ipv4/route.c:1556 rt_cache_valid+0x158/0x190 net/ipv4/route.c:1556 __mkroute_output net/ipv4/route.c:2332 [inline] ip_route_output_key_hash_rcu+0x819/0x2d50 net/ipv4/route.c:2564 ip_route_output_key_hash+0x1ef/0x360 net/ipv4/route.c:2393 __ip_route_output_key include/net/route.h:125 [inline] ip_route_output_flow+0x28/0xc0 net/ipv4/route.c:2651 ip_route_output_key include/net/route.h:135 [inline] ... or: kasan: GPF could be caused by NULL-ptr deref or user memory access RIP: 0010:dst_dev_put+0x24/0x290 net/core/dst.c:168 <IRQ> rt_fibinfo_free_cpus net/ipv4/fib_semantics.c:200 [inline] free_fib_info_rcu+0x2e1/0x490 net/ipv4/fib_semantics.c:217 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2437 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2716 [inline] rcu_process_callbacks+0x100a/0x1ac0 kernel/rcu/tree.c:2697 ... They were caused by the fib_nh_common percpu member 'nhc_pcpu_rth_output' overwritten by another percpu variable 'dev->tstats' access overflow in tipc udp media xmit path when counting packets on a non tunnel device. The fix is to make udp tunnel work with no tunnel device by allowing not to count packets on the tstats when the tunnel dev is NULL in Patches 1/3 and 2/3, then pass a NULL tunnel dev in tipc_udp_tunnel() in Patch 3/3. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/ip6_tunnel.h9
-rw-r--r--net/ipv4/ip_tunnel_core.c9
-rw-r--r--net/tipc/udp_media.c8
3 files changed, 15 insertions, 11 deletions
diff --git a/include/net/ip6_tunnel.h b/include/net/ip6_tunnel.h
index 69b4bcf880c9..028eaea1c854 100644
--- a/include/net/ip6_tunnel.h
+++ b/include/net/ip6_tunnel.h
@@ -158,9 +158,12 @@ static inline void ip6tunnel_xmit(struct sock *sk, struct sk_buff *skb,
memset(skb->cb, 0, sizeof(struct inet6_skb_parm));
pkt_len = skb->len - skb_inner_network_offset(skb);
err = ip6_local_out(dev_net(skb_dst(skb)->dev), sk, skb);
- if (unlikely(net_xmit_eval(err)))
- pkt_len = -1;
- iptunnel_xmit_stats(dev, pkt_len);
+
+ if (dev) {
+ if (unlikely(net_xmit_eval(err)))
+ pkt_len = -1;
+ iptunnel_xmit_stats(dev, pkt_len);
+ }
}
#endif
#endif
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c
index 9e3846388fb3..1452a97914a0 100644
--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -76,9 +76,12 @@ void iptunnel_xmit(struct sock *sk, struct rtable *rt, struct sk_buff *skb,
__ip_select_ident(net, iph, skb_shinfo(skb)->gso_segs ?: 1);
err = ip_local_out(net, sk, skb);
- if (unlikely(net_xmit_eval(err)))
- pkt_len = 0;
- iptunnel_xmit_stats(dev, pkt_len);
+
+ if (dev) {
+ if (unlikely(net_xmit_eval(err)))
+ pkt_len = 0;
+ iptunnel_xmit_stats(dev, pkt_len);
+ }
}
EXPORT_SYMBOL_GPL(iptunnel_xmit);
diff --git a/net/tipc/udp_media.c b/net/tipc/udp_media.c
index 7fc02d84c4f1..1405ccc9101c 100644
--- a/net/tipc/udp_media.c
+++ b/net/tipc/udp_media.c
@@ -176,7 +176,6 @@ static int tipc_udp_xmit(struct net *net, struct sk_buff *skb,
goto tx_error;
}
- skb->dev = rt->dst.dev;
ttl = ip4_dst_hoplimit(&rt->dst);
udp_tunnel_xmit_skb(rt, ub->ubsock->sk, skb, src->ipv4.s_addr,
dst->ipv4.s_addr, 0, ttl, 0, src->port,
@@ -195,10 +194,9 @@ static int tipc_udp_xmit(struct net *net, struct sk_buff *skb,
if (err)
goto tx_error;
ttl = ip6_dst_hoplimit(ndst);
- err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb,
- ndst->dev, &src->ipv6,
- &dst->ipv6, 0, ttl, 0, src->port,
- dst->port, false);
+ err = udp_tunnel6_xmit_skb(ndst, ub->ubsock->sk, skb, NULL,
+ &src->ipv6, &dst->ipv6, 0, ttl, 0,
+ src->port, dst->port, false);
#endif
}
return err;