From fb0aa0781a5f457e3864da68af52c3b1f4f7fd8f Mon Sep 17 00:00:00 2001 From: Wen Gu Date: Fri, 31 May 2024 16:54:17 +0800 Subject: [PATCH] net/smc: avoid overwriting when adjusting sock bufsizes When copying smc settings to clcsock, avoid setting clcsock's sk_sndbuf to sysctl_tcp_wmem[1], since this may overwrite the value set by tcp_sndbuf_expand() in TCP connection establishment. And the other setting sk_{snd|rcv}buf to sysctl value in smc_adjust_sock_bufsizes() can also be omitted since the initialization of smc sock and clcsock has set sk_{snd|rcv}buf to smc.sysctl_{w|r}mem or ipv4_sysctl_tcp_{w|r}mem[1]. Fixes: 30c3c4a4497c ("net/smc: Use correct buffer sizes when switching between TCP and SMC") Link: https://lore.kernel.org/r/5eaf3858-e7fd-4db8-83e8-3d7a3e0e9ae2@linux.alibaba.com Signed-off-by: Wen Gu Reviewed-by: Wenjia Zhang Reviewed-by: Gerd Bayer , too. Signed-off-by: David S. Miller --- net/smc/af_smc.c | 22 ++-------------------- 1 file changed, 2 insertions(+), 20 deletions(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index e50a286fd0fb..c5f98c6b2561 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -459,29 +459,11 @@ out: static void smc_adjust_sock_bufsizes(struct sock *nsk, struct sock *osk, unsigned long mask) { - struct net *nnet = sock_net(nsk); - nsk->sk_userlocks = osk->sk_userlocks; - if (osk->sk_userlocks & SOCK_SNDBUF_LOCK) { + if (osk->sk_userlocks & SOCK_SNDBUF_LOCK) nsk->sk_sndbuf = osk->sk_sndbuf; - } else { - if (mask == SK_FLAGS_SMC_TO_CLC) - WRITE_ONCE(nsk->sk_sndbuf, - READ_ONCE(nnet->ipv4.sysctl_tcp_wmem[1])); - else - WRITE_ONCE(nsk->sk_sndbuf, - 2 * READ_ONCE(nnet->smc.sysctl_wmem)); - } - if (osk->sk_userlocks & SOCK_RCVBUF_LOCK) { + if (osk->sk_userlocks & SOCK_RCVBUF_LOCK) nsk->sk_rcvbuf = osk->sk_rcvbuf; - } else { - if (mask == SK_FLAGS_SMC_TO_CLC) - WRITE_ONCE(nsk->sk_rcvbuf, - READ_ONCE(nnet->ipv4.sysctl_tcp_rmem[1])); - else - WRITE_ONCE(nsk->sk_rcvbuf, - 2 * READ_ONCE(nnet->smc.sysctl_rmem)); - } } static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,