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Commit 7d0354c9 authored by Tony Lu's avatar Tony Lu Committed by Greg Kroah-Hartman
Browse files

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@linux.ibm.com/


Fixes: 606a63c9783a ("net/smc: Ensure the active closing peer first closes clcsock")
Signed-off-by: default avatarTony Lu <tonylu@linux.alibaba.com>
Reviewed-by: default avatarWen Gu <guwen@linux.alibaba.com>
Acked-by: default avatarKarsten Graul <kgraul@linux.ibm.com>
Link: https://lore.kernel.org/r/20211126024134.45693-1-tonylu@linux.alibaba.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent fd25bc47

net/smc/af_smc.c

+7 −1
Original line number Diff line number Diff line
@@ -1589,8 +1589,10 @@ 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);
@@ -1617,7 +1619,11 @@ 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);
@@ -1627,7 +1633,7 @@ 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;