[PATCH 5.4 02/43] ibmvnic fix NULL tx_pools and rx_tools issue at do_reset

Greg Kroah-Hartman
2020-09-25T12:51:20Z

From: Mingming Cao <mmc@linux.vnet.ibm.com>

[ Upstream commit 9f13457377907fa253aef560e1a37e1ca4197f9b ]

At the time of do_rest, ibmvnic tries to re-initalize the tx_pools
and rx_pools to avoid re-allocating the long term buffer. However
there is a window inside do_reset that the tx_pools and
rx_pools were freed before re-initialized making it possible to deference
null pointers.

This patch fix this issue by always check the tx_pool
and rx_pool are not NULL after ibmvnic_login. If so, re-allocating
the pools. This will avoid getting into calling reset_tx/rx_pools with
NULL adapter tx_pools/rx_pools pointer. Also add null pointer check in
reset_tx_pools and reset_rx_pools to safe handle NULL pointer case.

Signed-off-by: Mingming Cao <mmc@linux.vnet.ibm.com>
Signed-off-by: Dany Madden <drt@linux.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 | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 2d20a48f0ba0a..de45b3709c14e 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -416,6 +416,9 @@ static int reset_rx_pools(struct ibmvnic_adapter *adapter)
int i, j, rc;
u64 *size_array;

+ if (!adapter->rx_pool)
+ return -1;
+
size_array = (u64 *)((u8 *)(adapter->login_rsp_buf) +
be32_to_cpu(adapter->login_rsp_buf->off_rxadd_buff_size));

@@ -586,6 +589,9 @@ static int reset_tx_pools(struct ibmvnic_adapter *adapter)
int tx_scrqs;
int i, rc;

+ if (!adapter->tx_pool)
+ return -1;
+
tx_scrqs = be32_to_cpu(adapter->login_rsp_buf->num_txsubm_subcrqs);
for (i = 0; i < tx_scrqs; i++) {
rc = reset_one_tx_pool(adapter, &adapter->tso_pool[i]);
@@ -1918,7 +1924,10 @@ static int do_reset(struct ibmvnic_adapter *adapter,
adapter->req_rx_add_entries_per_subcrq !=
old_num_rx_slots ||
adapter->req_tx_entries_per_subcrq !=
- old_num_tx_slots) {
+ old_num_tx_slots ||
+ !adapter->rx_pool ||
+ !adapter->tso_pool ||
+ !adapter->tx_pool) {
release_rx_pools(adapter);
release_tx_pools(adapter);
release_napi(adapter);
@@ -1931,10 +1940,14 @@ static int do_reset(struct ibmvnic_adapter *adapter,
} else {
rc = reset_tx_pools(adapter);
if (rc)
+ netdev_dbg(adapter->netdev, "reset tx pools failed (%d)\n",
+ rc);
goto out;

rc = reset_rx_pools(adapter);
if (rc)
+ netdev_dbg(adapter->netdev, "reset rx pools failed (%d)\n",
+ rc);
goto out;
}
ibmvnic_disable_irqs(adapter);
--
2.25.1