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authorEric Dumazet <edumazet@google.com>2019-10-29 20:54:44 +0300
committerDavid S. Miller <davem@davemloft.net>2019-10-31 03:34:35 +0300
commitee8d153d46a3b98c064ee15c0c0a3bbf1450e5a1 (patch)
treefb345d15f66a0e2656aaa96bca10531e478707e0
parent7170a977743b72cf3eb46ef6ef89885dc7ad3621 (diff)
downloadlinux-ee8d153d46a3b98c064ee15c0c0a3bbf1450e5a1.tar.xz
net: annotate lockless accesses to sk->sk_napi_id
We already annotated most accesses to sk->sk_napi_id We missed sk_mark_napi_id() and sk_mark_napi_id_once() which might be called without socket lock held in UDP stack. KCSAN reported : BUG: KCSAN: data-race in udpv6_queue_rcv_one_skb / udpv6_queue_rcv_one_skb write to 0xffff888121c6d108 of 4 bytes by interrupt on cpu 0: sk_mark_napi_id include/net/busy_poll.h:125 [inline] __udpv6_queue_rcv_skb net/ipv6/udp.c:571 [inline] udpv6_queue_rcv_one_skb+0x70c/0xb40 net/ipv6/udp.c:672 udpv6_queue_rcv_skb+0xb5/0x400 net/ipv6/udp.c:689 udp6_unicast_rcv_skb.isra.0+0xd7/0x180 net/ipv6/udp.c:832 __udp6_lib_rcv+0x69c/0x1770 net/ipv6/udp.c:913 udpv6_rcv+0x2b/0x40 net/ipv6/udp.c:1015 ip6_protocol_deliver_rcu+0x22a/0xbe0 net/ipv6/ip6_input.c:409 ip6_input_finish+0x30/0x50 net/ipv6/ip6_input.c:450 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip6_input+0x177/0x190 net/ipv6/ip6_input.c:459 dst_input include/net/dst.h:442 [inline] ip6_rcv_finish+0x110/0x140 net/ipv6/ip6_input.c:76 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ipv6_rcv+0x1a1/0x1b0 net/ipv6/ip6_input.c:284 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124 process_backlog+0x1d3/0x420 net/core/dev.c:5955 napi_poll net/core/dev.c:6392 [inline] net_rx_action+0x3ae/0xa90 net/core/dev.c:6460 write to 0xffff888121c6d108 of 4 bytes by interrupt on cpu 1: sk_mark_napi_id include/net/busy_poll.h:125 [inline] __udpv6_queue_rcv_skb net/ipv6/udp.c:571 [inline] udpv6_queue_rcv_one_skb+0x70c/0xb40 net/ipv6/udp.c:672 udpv6_queue_rcv_skb+0xb5/0x400 net/ipv6/udp.c:689 udp6_unicast_rcv_skb.isra.0+0xd7/0x180 net/ipv6/udp.c:832 __udp6_lib_rcv+0x69c/0x1770 net/ipv6/udp.c:913 udpv6_rcv+0x2b/0x40 net/ipv6/udp.c:1015 ip6_protocol_deliver_rcu+0x22a/0xbe0 net/ipv6/ip6_input.c:409 ip6_input_finish+0x30/0x50 net/ipv6/ip6_input.c:450 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ip6_input+0x177/0x190 net/ipv6/ip6_input.c:459 dst_input include/net/dst.h:442 [inline] ip6_rcv_finish+0x110/0x140 net/ipv6/ip6_input.c:76 NF_HOOK include/linux/netfilter.h:305 [inline] NF_HOOK include/linux/netfilter.h:299 [inline] ipv6_rcv+0x1a1/0x1b0 net/ipv6/ip6_input.c:284 __netif_receive_skb_one_core+0xa7/0xe0 net/core/dev.c:5010 __netif_receive_skb+0x37/0xf0 net/core/dev.c:5124 process_backlog+0x1d3/0x420 net/core/dev.c:5955 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 10890 Comm: syz-executor.0 Not tainted 5.4.0-rc3+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: e68b6e50fa35 ("udp: enable busy polling for all sockets") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--include/net/busy_poll.h6
1 files changed, 3 insertions, 3 deletions
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index 127a5c4e3699..86e028388bad 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -122,7 +122,7 @@ static inline void skb_mark_napi_id(struct sk_buff *skb,
static inline void sk_mark_napi_id(struct sock *sk, const struct sk_buff *skb)
{
#ifdef CONFIG_NET_RX_BUSY_POLL
- sk->sk_napi_id = skb->napi_id;
+ WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
#endif
sk_rx_queue_set(sk, skb);
}
@@ -132,8 +132,8 @@ static inline void sk_mark_napi_id_once(struct sock *sk,
const struct sk_buff *skb)
{
#ifdef CONFIG_NET_RX_BUSY_POLL
- if (!sk->sk_napi_id)
- sk->sk_napi_id = skb->napi_id;
+ if (!READ_ONCE(sk->sk_napi_id))
+ WRITE_ONCE(sk->sk_napi_id, skb->napi_id);
#endif
}