From 67f562e3e147750a02b2a91d21a163fc44a1d13e Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Fri, 14 Feb 2020 08:58:59 +0100 Subject: [PATCH 1/2] net/smc: transfer fasync_list in case of fallback SMC does not work together with FASTOPEN. If sendmsg() is called with flag MSG_FASTOPEN in SMC_INIT state, the SMC-socket switches to fallback mode. To handle the previous ioctl FIOASYNC call correctly in this case, it is necessary to transfer the socket wait queue fasync_list to the internal TCP socket. Reported-by: syzbot+4b1fe8105f8044a26162@syzkaller.appspotmail.com Fixes: ee9dfbef02d18 ("net/smc: handle sockopts forcing fallback") Signed-off-by: Ursula Braun Signed-off-by: Karsten Graul Signed-off-by: David S. Miller --- net/smc/af_smc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index cee5bf4a9bb9..90988a511cd5 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -470,6 +470,8 @@ static void smc_switch_to_fallback(struct smc_sock *smc) if (smc->sk.sk_socket && smc->sk.sk_socket->file) { smc->clcsock->file = smc->sk.sk_socket->file; smc->clcsock->file->private_data = smc->clcsock; + smc->clcsock->wq.fasync_list = + smc->sk.sk_socket->wq.fasync_list; } } From 369537c97024dca99303a8d4d6ab38b4f54d3909 Mon Sep 17 00:00:00 2001 From: Ursula Braun Date: Fri, 14 Feb 2020 08:59:00 +0100 Subject: [PATCH 2/2] net/smc: no peer ID in CLC decline for SMCD Just SMCR requires a CLC Peer ID, but not SMCD. The field should be zero for SMCD. Fixes: c758dfddc1b5 ("net/smc: add SMC-D support in CLC messages") Signed-off-by: Ursula Braun Signed-off-by: Karsten Graul Signed-off-by: David S. Miller --- net/smc/smc_clc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/smc/smc_clc.c b/net/smc/smc_clc.c index 0879f7bed967..86cccc24e52e 100644 --- a/net/smc/smc_clc.c +++ b/net/smc/smc_clc.c @@ -372,7 +372,9 @@ int smc_clc_send_decline(struct smc_sock *smc, u32 peer_diag_info) dclc.hdr.length = htons(sizeof(struct smc_clc_msg_decline)); dclc.hdr.version = SMC_CLC_V1; dclc.hdr.flag = (peer_diag_info == SMC_CLC_DECL_SYNCERR) ? 1 : 0; - memcpy(dclc.id_for_peer, local_systemid, sizeof(local_systemid)); + if (smc->conn.lgr && !smc->conn.lgr->is_smcd) + memcpy(dclc.id_for_peer, local_systemid, + sizeof(local_systemid)); dclc.peer_diagnosis = htonl(peer_diag_info); memcpy(dclc.trl.eyecatcher, SMC_EYECATCHER, sizeof(SMC_EYECATCHER));