[PATCH 5.19 079/158] net: Fix a data-race around gro_normal_batch.

Greg Kroah-Hartman
2022-08-29T12:17:26Z

From: Kuniyuki Iwashima <kuniyu@amazon.com>

[ Upstream commit 8db24af3f02ebdbf302196006ebb270c4c3a2706 ]

While reading gro_normal_batch, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its reader.

Fixes: 323ebb61e32b ("net: use listified RX for handling GRO_NORMAL skbs")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Edward Cree <ecree.xilinx@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/net/gro.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/gro.h b/include/net/gro.h
index 867656b0739c0..24003dea8fa4d 100644
--- a/include/net/gro.h
+++ b/include/net/gro.h
@@ -439,7 +439,7 @@ static inline void gro_normal_one(struct napi_struct *napi, struct sk_buff *skb,
{
list_add_tail(&skb->list, &napi->rx_list);
napi->rx_count += segs;
- if (napi->rx_count >= gro_normal_batch)
+ if (napi->rx_count >= READ_ONCE(gro_normal_batch))
gro_normal_list(napi);
}

--
2.35.1