tcp: Fix data-races around sysctl_tcp_max_reordering.

[ Upstream commit a11e5b3e7a59fde1a90b0eaeaa82320495cf8cae ]

While reading sysctl_tcp_max_reordering, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its readers.

Fixes: dca145ffaa ("tcp: allow for bigger reordering level")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Kuniyuki Iwashima 2022-07-18 10:26:53 -07:00 committed by Greg Kroah-Hartman
parent 805f1c7ce4
commit 0648526633

View File

@ -1011,7 +1011,7 @@ static void tcp_check_sack_reordering(struct sock *sk, const u32 low_seq,
tp->undo_marker ? tp->undo_retrans : 0);
#endif
tp->reordering = min_t(u32, (metric + mss - 1) / mss,
sock_net(sk)->ipv4.sysctl_tcp_max_reordering);
READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_max_reordering));
}
/* This exciting event is worth to be remembered. 8) */
@ -1990,7 +1990,7 @@ static void tcp_check_reno_reordering(struct sock *sk, const int addend)
return;
tp->reordering = min_t(u32, tp->packets_out + addend,
sock_net(sk)->ipv4.sysctl_tcp_max_reordering);
READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_max_reordering));
tp->reord_seen++;
NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPRENOREORDER);
}