From 49bbeb5719c2f56907d3a9623b47c6c15c2c431d Mon Sep 17 00:00:00 2001 From: Nick Child Date: Thu, 20 Jun 2024 10:23:12 -0500 Subject: ibmvnic: Free any outstanding tx skbs during scrq reset There are 2 types of outstanding tx skb's: Type 1: Packets that are sitting in the drivers ind_buff that are waiting to be batch sent to the NIC. During a device reset, these are freed with a call to ibmvnic_tx_scrq_clean_buffer() Type 2: Packets that have been sent to the NIC and are awaiting a TX completion IRQ. These are free'd during a reset with a call to clean_tx_pools() During any reset which requires us to free the tx irq, ensure that the Type 2 skb references are freed. Since the irq is released, it is impossible for the NIC to inform of any completions. Furthermore, later in the reset process is a call to init_tx_pools() which marks every entry in the tx pool as free (ie not outstanding). So if the driver is to make a call to init_tx_pools(), it must first be sure that the tx pool is empty of skb references. This issue was discovered by observing the following in the logs during EEH testing: TX free map points to untracked skb (tso_pool 0 idx=4) TX free map points to untracked skb (tso_pool 0 idx=5) TX free map points to untracked skb (tso_pool 1 idx=36) Fixes: 65d6470d139a ("ibmvnic: clean pending indirect buffs during reset") Signed-off-by: Nick Child Signed-off-by: David S. Miller --- drivers/net/ethernet/ibm/ibmvnic.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'drivers/net/ethernet/ibm/ibmvnic.c') diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 5e9a93bdb518..5490f0f9c112 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -4061,6 +4061,12 @@ static void release_sub_crqs(struct ibmvnic_adapter *adapter, bool do_h_free) adapter->num_active_tx_scrqs = 0; } + /* Clean any remaining outstanding SKBs + * we freed the irq so we won't be hearing + * from them + */ + clean_tx_pools(adapter); + if (adapter->rx_scrq) { for (i = 0; i < adapter->num_active_rx_scrqs; i++) { if (!adapter->rx_scrq[i]) -- cgit v1.2.3 From 0983d288caf984de0202c66641577b739caad561 Mon Sep 17 00:00:00 2001 From: Nick Child Date: Thu, 20 Jun 2024 10:23:11 -0500 Subject: ibmvnic: Add tx check to prevent skb leak Below is a summary of how the driver stores a reference to an skb during transmit: tx_buff[free_map[consumer_index]]->skb = new_skb; free_map[consumer_index] = IBMVNIC_INVALID_MAP; consumer_index ++; Where variable data looks like this: free_map == [4, IBMVNIC_INVALID_MAP, IBMVNIC_INVALID_MAP, 0, 3] consumer_index^ tx_buff == [skb=null, skb=, skb=, skb=null, skb=null] The driver has checks to ensure that free_map[consumer_index] pointed to a valid index but there was no check to ensure that this index pointed to an unused/null skb address. So, if, by some chance, our free_map and tx_buff lists become out of sync then we were previously risking an skb memory leak. This could then cause tcp congestion control to stop sending packets, eventually leading to ETIMEDOUT. Therefore, add a conditional to ensure that the skb address is null. If not then warn the user (because this is still a bug that should be patched) and free the old pointer to prevent memleak/tcp problems. Signed-off-by: Nick Child Signed-off-by: Paolo Abeni --- drivers/net/ethernet/ibm/ibmvnic.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/net/ethernet/ibm/ibmvnic.c') diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index 5490f0f9c112..23ebeb143987 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -2482,6 +2482,18 @@ static netdev_tx_t ibmvnic_xmit(struct sk_buff *skb, struct net_device *netdev) (tx_pool->consumer_index + 1) % tx_pool->num_buffers; tx_buff = &tx_pool->tx_buff[bufidx]; + + /* Sanity checks on our free map to make sure it points to an index + * that is not being occupied by another skb. If skb memory is + * not freed then we see congestion control kick in and halt tx. + */ + if (unlikely(tx_buff->skb)) { + dev_warn_ratelimited(dev, "TX free map points to untracked skb (%s %d idx=%d)\n", + skb_is_gso(skb) ? "tso_pool" : "tx_pool", + queue_num, bufidx); + dev_kfree_skb_any(tx_buff->skb); + } + tx_buff->skb = skb; tx_buff->index = bufidx; tx_buff->pool_index = queue_num; -- cgit v1.2.3