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authorKuniyuki Iwashima <kuniyu@amazon.com>2022-07-22 21:22:04 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-08-03 13:00:48 +0300
commite4a7acd6b443c15dcf269df4e04992408573e674 (patch)
tree578101d1d7d2264217b46cdf6d376bb026d23c66 /net/ipv6
parentf310fb69a0a833b325bf36b21587ae0e52450d58 (diff)
downloadlinux-e4a7acd6b443c15dcf269df4e04992408573e674.tar.xz
tcp: Fix data-races around sysctl_tcp_reflect_tos.
[ Upstream commit 870e3a634b6a6cb1543b359007aca73fe6a03ac5 ] While reading sysctl_tcp_reflect_tos, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers. Fixes: ac8f1710c12b ("tcp: reflect tos value received in SYN to the socket") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Acked-by: Wei Wang <weiwan@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'net/ipv6')
-rw-r--r--net/ipv6/tcp_ipv6.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 303b54414a6c..8d91f36cb11b 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -542,7 +542,7 @@ static int tcp_v6_send_synack(const struct sock *sk, struct dst_entry *dst,
if (np->repflow && ireq->pktopts)
fl6->flowlabel = ip6_flowlabel(ipv6_hdr(ireq->pktopts));
- tclass = sock_net(sk)->ipv4.sysctl_tcp_reflect_tos ?
+ tclass = READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos) ?
(tcp_rsk(req)->syn_tos & ~INET_ECN_MASK) |
(np->tclass & INET_ECN_MASK) :
np->tclass;
@@ -1344,7 +1344,7 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
/* Set ToS of the new socket based upon the value of incoming SYN.
* ECT bits are set later in tcp_init_transfer().
*/
- if (sock_net(sk)->ipv4.sysctl_tcp_reflect_tos)
+ if (READ_ONCE(sock_net(sk)->ipv4.sysctl_tcp_reflect_tos))
newnp->tclass = tcp_rsk(req)->syn_tos & ~INET_ECN_MASK;
/* Clone native IPv6 options from listening socket (if any)