This is a note to let you know that I've just added the patch titled net/smc: Don't call clcsock shutdown twice when smc shutdown to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-smc-don-t-call-clcsock-shutdown-twice-when-smc-s.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit feb2d0ba5b32faf3d0492662b168bf94974cc9ac Author: Tony Lu <tonylu@xxxxxxxxxxxxxxxxx> Date: Fri Nov 26 10:41:35 2021 +0800 net/smc: Don't call clcsock shutdown twice when smc shutdown [ 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> diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index a0d3f4e07b067..ac8265e35b2d2 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -2098,8 +2098,10 @@ 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); @@ -2126,7 +2128,11 @@ 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); @@ -2136,7 +2142,7 @@ 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;