[PATCH AUTOSEL 5.4 21/49] ibmvnic: Skip fatal error reset after passive init

From: Sasha Levin
Date: Thu May 14 2020 - 15:07:24 EST


From: Juliet Kim <julietk@xxxxxxxxxxxxxxxxxx>

[ Upstream commit f9c6cea0b38518741c8dcf26ac056d26ee2fd61d ]

During MTU change, the following events may happen.
Client-driven CRQ initialization fails due to partnerâs 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@xxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 e1ab2feeae53d..aaa03ce5796f4 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);
--
2.20.1