[PATCH 5.11 130/210] ethernet: myri10ge: Fix a use after free in myri10ge_sw_tso

Greg Kroah-Hartman
2021-04-12T09:37:39Z

From: Lv Yunlong <lyl2019@mail.ustc.edu.cn>

[ Upstream commit 63415767a2446136372e777cde5bb351f21ec21d ]

In myri10ge_sw_tso, the skb_list_walk_safe macro will set
(curr) = (segs) and (next) = (curr)->next. If status!=0 is true,
the memory pointed by curr and segs will be free by dev_kfree_skb_any(curr).
But later, the segs is used by segs = segs->next and causes a uaf.

As (next) = (curr)->next, my patch replaces seg->next to next.

Fixes: 536577f36ff7a ("net: myri10ge: use skb_list_walk_safe helper for gso segments")
Signed-off-by: Lv Yunlong <lyl2019@mail.ustc.edu.cn>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/ethernet/myricom/myri10ge/myri10ge.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
index 1634ca6d4a8f..c84c8bf2bc20 100644
--- a/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
+++ b/drivers/net/ethernet/myricom/myri10ge/myri10ge.c
@@ -2897,7 +2897,7 @@ static netdev_tx_t myri10ge_sw_tso(struct sk_buff *skb,
dev_kfree_skb_any(curr);
if (segs != NULL) {
curr = segs;
- segs = segs->next;
+ segs = next;
curr->next = NULL;
dev_kfree_skb_any(segs);
}
--
2.30.2