[PATCH 4.9 52/65] RDMA/iw_cxgb4: Avoid freeing skb twice in arp failure case

[Greg Kroah-Hartman]

From: Potnuri Bharat Teja <bharat@xxxxxxxxxxx>

[ Upstream commit d4934f45693651ea15357dd6c7c36be28b6da884 ]

_put_ep_safe() and _put_pass_ep_safe() free the skb before it is freed by
process_work(). fix double free by freeing the skb only in process_work().

Fixes: 1dad0ebeea1c ("iw_cxgb4: Avoid touch after free error in ARP failure handlers")
Link: https://lore.kernel.org/r/1572006880-5800-1-git-send-email-bharat@xxxxxxxxxxx
Signed-off-by: Dakshaja Uppalapati <dakshaja@xxxxxxxxxxx>
Signed-off-by: Potnuri Bharat Teja <bharat@xxxxxxxxxxx>
Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/infiniband/hw/cxgb4/cm.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index e5752352e0fb1..605d50ad123cc 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -490,7 +490,6 @@ static int _put_ep_safe(struct c4iw_dev *dev, struct sk_buff *skb)
 
 	ep = *((struct c4iw_ep **)(skb->cb + 2 * sizeof(void *)));
 	release_ep_resources(ep);
-	kfree_skb(skb);
 	return 0;
 }
 
@@ -501,7 +500,6 @@ static int _put_pass_ep_safe(struct c4iw_dev *dev, struct sk_buff *skb)
 	ep = *((struct c4iw_ep **)(skb->cb + 2 * sizeof(void *)));
 	c4iw_put_ep(&ep->parent_ep->com);
 	release_ep_resources(ep);
-	kfree_skb(skb);
 	return 0;
 }
 
-- 
2.20.1