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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Juliet Kim <julietk@linux.vnet.ibm.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 034/111] ibmvnic: Skip fatal error reset after passive init
Date:   Tue, 26 May 2020 20:52:52 +0200
Message-Id: <20200526183936.067512660@linuxfoundation.org>
In-Reply-To: <20200526183932.245016380@linuxfoundation.org>
References: <20200526183932.245016380@linuxfoundation.org>
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From: Juliet Kim <julietk@linux.vnet.ibm.com>

[ Upstream commit f9c6cea0b38518741c8dcf26ac056d26ee2fd61d ]

During MTU change, the following events may happen.
Client-driven CRQ initialization fails due to partner’s CRQ closed,
causing client to enqueue a reset task for FATAL_ERROR. Then passive
(server-driven) CRQ initialization succeeds, causing client to
release CRQ and enqueue a reset task for failover. If the passive
CRQ initialization occurs before the FATAL reset task is processed,
the FATAL error reset task would try to access a CRQ message queue
that was freed, causing an oops. The problem may be most likely to
occur during DLPAR add vNIC with a non-default MTU, because the DLPAR
process will automatically issue a change MTU request.

Fix this by not processing fatal error reset if CRQ is passively
initialized after client-driven CRQ initialization fails.

Signed-off-by: Juliet Kim <julietk@linux.vnet.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/ethernet/ibm/ibmvnic.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index e1ab2feeae53..aaa03ce5796f 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -2086,7 +2086,8 @@ static void __ibmvnic_reset(struct work_struct *work)
 				rc = do_hard_reset(adapter, rwi, reset_state);
 				rtnl_unlock();
 			}
-		} else {
+		} else if (!(rwi->reset_reason == VNIC_RESET_FATAL &&
+				adapter->from_passive_init)) {
 			rc = do_reset(adapter, rwi, reset_state);
 		}
 		kfree(rwi);
-- 
2.25.1