Commit e1bc684c authored Apr 14, 2022 by Tony Lu Committed by Greg Kroah-Hartman Apr 27, 2022

net/smc: Fix sock leak when release after smc_shutdown()



[ Upstream commit 1a74e99323746353bba11562a2f2d0aa8102f402 ]

Since commit e5d5aadcf3cd ("net/smc: fix sk_refcnt underflow on linkdown
and fallback"), for a fallback connection, __smc_release() does not call
sock_put() if its state is already SMC_CLOSED.

When calling smc_shutdown() after falling back, its state is set to
SMC_CLOSED but does not call sock_put(), so this patch calls it.

Reported-and-tested-by:  <syzbot+6e29a053eb165bd50de5@syzkaller.appspotmail.com>
Fixes: e5d5aadcf3cd ("net/smc: fix sk_refcnt underflow on linkdown and fallback")
Signed-off-by: Tony Lu <tonylu@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

parent f10e5c9f

net/smc/af_smc.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -1698,8 +1698,10 @@ static int smc_shutdown(struct socket *sock, int how)
		if (smc->use_fallback) {
		rc = kernel_sock_shutdown(smc->clcsock, how);
		sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
		if (sk->sk_shutdown == SHUTDOWN_MASK)
		if (sk->sk_shutdown == SHUTDOWN_MASK) {
		sk->sk_state = SMC_CLOSED;
		sock_put(sk);
		}
		goto out;
		}
		switch (how) {