From: Tony Lu <tonylu@xxxxxxxxxxxxxxxxx> [ Upstream commit bacb6c1e47691cda4a95056c21b5487fb7199fcc ] When applications call shutdown() with SHUT_RDWR in userspace, smc_close_active() calls kernel_sock_shutdown(), and it is called twice in smc_shutdown(). This fixes this by checking sk_state before do clcsock shutdown, and avoids missing the application's call of smc_shutdown(). Link: https://lore.kernel.org/linux-s390/1f67548e-cbf6-0dce-82b5-10288a4583bd@xxxxxxxxxxxxx/ Fixes: 606a63c9783a ("net/smc: Ensure the active closing peer first closes clcsock") Signed-off-by: Tony Lu <tonylu@xxxxxxxxxxxxxxxxx> Reviewed-by: Wen Gu <guwen@xxxxxxxxxxxxxxxxx> Acked-by: Karsten Graul <kgraul@xxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20211126024134.45693-1-tonylu@xxxxxxxxxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/smc/af_smc.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 4f1fa1bcb0316..3d8219e3b0264 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -2154,8 +2154,10 @@ static __poll_t smc_poll(struct file *file, struct socket *sock, static int smc_shutdown(struct socket *sock, int how) { struct sock *sk = sock->sk; + bool do_shutdown = true; struct smc_sock *smc; int rc = -EINVAL; + int old_state; int rc1 = 0; smc = smc_sk(sk); @@ -2182,7 +2184,11 @@ static int smc_shutdown(struct socket *sock, int how) } switch (how) { case SHUT_RDWR: /* shutdown in both directions */ + old_state = sk->sk_state; rc = smc_close_active(smc); + if (old_state == SMC_ACTIVE && + sk->sk_state == SMC_PEERCLOSEWAIT1) + do_shutdown = false; break; case SHUT_WR: rc = smc_close_shutdown_write(smc); @@ -2192,7 +2198,7 @@ static int smc_shutdown(struct socket *sock, int how) /* nothing more to do because peer is not involved */ break; } - if (smc->clcsock) + if (do_shutdown && smc->clcsock) rc1 = kernel_sock_shutdown(smc->clcsock, how); /* map sock_shutdown_cmd constants to sk_shutdown value range */ sk->sk_shutdown |= how + 1; -- 2.33.0
