diff options
| author | Eric Dumazet | 2021-10-25 09:48:23 -0700 |
|---|---|---|
| committer | Jakub Kicinski | 2021-10-25 18:02:13 -0700 |
| commit | 14834c4f4eb3c8c0af40f6203dbf09d232044d9d (patch) | |
| tree | 714e8ea9aa75d7e5cc1d7d418401ed3474716dba /net/ipv4 | |
| parent | 790eb67374d43f66102a80821d22188b6a0bc3bb (diff) | |
ipv4: annotate data races arount inet->min_ttl
No report yet from KCSAN, yet worth documenting the races.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/ip_sockglue.c | 5 | ||||
| -rw-r--r-- | net/ipv4/tcp_ipv4.c | 7 |
2 files changed, 9 insertions, 3 deletions
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index b297bb28556e..d5487c858067 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -1352,7 +1352,10 @@ static int do_ip_setsockopt(struct sock *sk, int level, int optname, goto e_inval; if (val < 0 || val > 255) goto e_inval; - inet->min_ttl = val; + /* tcp_v4_err() and tcp_v4_rcv() might read min_ttl + * while we are changint it. + */ + WRITE_ONCE(inet->min_ttl, val); break; default: diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index 2bdc32c1afb6..a9cbc8e6b796 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -508,7 +508,8 @@ int tcp_v4_err(struct sk_buff *skb, u32 info) if (sk->sk_state == TCP_CLOSE) goto out; - if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { + /* min_ttl can be changed concurrently from do_ip_setsockopt() */ + if (unlikely(iph->ttl < READ_ONCE(inet_sk(sk)->min_ttl))) { __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); goto out; } @@ -2068,7 +2069,9 @@ process: return 0; } } - if (unlikely(iph->ttl < inet_sk(sk)->min_ttl)) { + + /* min_ttl can be changed concurrently from do_ip_setsockopt() */ + if (unlikely(iph->ttl < READ_ONCE(inet_sk(sk)->min_ttl))) { __NET_INC_STATS(net, LINUX_MIB_TCPMINTTLDROP); goto discard_and_relse; } |