From: Kuniyuki Iwashima kuniyu@amazon.com
[ Upstream commit 657b991afb89d25fe6c4783b1b75a8ad4563670d ]
While reading sysctl_max_skb_frags, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers.
Fixes: 5f74f82ea34c ("net:Add sysctl_max_skb_frags") 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 --- net/ipv4/tcp.c | 4 ++-- net/mptcp/protocol.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 3ae2ea0488838..3d446773ff2a5 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -1000,7 +1000,7 @@ static struct sk_buff *tcp_build_frag(struct sock *sk, int size_goal, int flags,
i = skb_shinfo(skb)->nr_frags; can_coalesce = skb_can_coalesce(skb, i, page, offset); - if (!can_coalesce && i >= sysctl_max_skb_frags) { + if (!can_coalesce && i >= READ_ONCE(sysctl_max_skb_frags)) { tcp_mark_push(tp, skb); goto new_segment; } @@ -1348,7 +1348,7 @@ int tcp_sendmsg_locked(struct sock *sk, struct msghdr *msg, size_t size)
if (!skb_can_coalesce(skb, i, pfrag->page, pfrag->offset)) { - if (i >= sysctl_max_skb_frags) { + if (i >= READ_ONCE(sysctl_max_skb_frags)) { tcp_mark_push(tp, skb); goto new_segment; } diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 3d90fa9653ef3..513f571a082ba 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1299,7 +1299,7 @@ static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk,
i = skb_shinfo(skb)->nr_frags; can_coalesce = skb_can_coalesce(skb, i, dfrag->page, offset); - if (!can_coalesce && i >= sysctl_max_skb_frags) { + if (!can_coalesce && i >= READ_ONCE(sysctl_max_skb_frags)) { tcp_mark_push(tcp_sk(ssk), skb); goto alloc_skb; }