From 72368f8b2b9e4106072a2728bed3367d54641c22 Mon Sep 17 00:00:00 2001
From: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Date: Wed, 23 Jun 2021 21:13:13 -0700
Subject: [PATCH] ibmvnic: account for bufs already saved in indir_buf
References: jsc#SLE-17268 jsc#SLE-17043 bsc#1179243 ltc#189290 bsc#1188620 ltc#192221
Patch-mainline: v5.14-rc1
Git-commit: 72368f8b2b9e4106072a2728bed3367d54641c22
This fixes a crash in replenish_rx_pool() when called from ibmvnic_poll()
after a previous call to replenish_rx_pool() encountered an error when
allocating a socket buffer.
Thanks to Rick Lindsley and Dany Madden for helping debug the crash.
Fixes: 4f0b6812e9b9 ("ibmvnic: Introduce batched RX buffer descriptor transmission")
Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Suchanek <msuchanek@suse.de>
---
drivers/net/ethernet/ibm/ibmvnic.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c
index 2d15b446ceb3..779de81a54a6 100644
--- a/drivers/net/ethernet/ibm/ibmvnic.c
+++ b/drivers/net/ethernet/ibm/ibmvnic.c
@@ -328,7 +328,14 @@ static void replenish_rx_pool(struct ibmvnic_adapter *adapter,
rx_scrq = adapter->rx_scrq[pool->index];
ind_bufp = &rx_scrq->ind_buf;
- for (i = 0; i < count; ++i) {
+
+ /* netdev_skb_alloc() could have failed after we saved a few skbs
+ * in the indir_buf and we would not have sent them to VIOS yet.
+ * To account for them, start the loop at ind_bufp->index rather
+ * than 0. If we pushed all the skbs to VIOS, ind_bufp->index will
+ * be 0.
+ */
+ for (i = ind_bufp->index; i < count; ++i) {
skb = netdev_alloc_skb(adapter->netdev, pool->buff_size);
if (!skb) {
dev_err(dev, "Couldn't replenish rx buff\n");
--
2.26.2