[PATCH 4.19 25/56] net: Fix a data-race around netdev_budget.

Greg Kroah-Hartman
2022-09-02T12:53:34Z

From: Kuniyuki Iwashima <kuniyu@amazon.com>

[ Upstream commit 2e0c42374ee32e72948559d2ae2f7ba3dc6b977c ]

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

Fixes: 51b0bdedb8e7 ("[NET]: Separate two usages of netdev_max_backlog.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/core/dev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/dev.c b/net/core/dev.c
index d5bef2bb0b7c8..c93068ea2e4f2 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6336,7 +6336,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h)
struct softnet_data *sd = this_cpu_ptr(&softnet_data);
unsigned long time_limit = jiffies +
usecs_to_jiffies(netdev_budget_usecs);
- int budget = netdev_budget;
+ int budget = READ_ONCE(netdev_budget);
LIST_HEAD(list);
LIST_HEAD(repoll);

--
2.35.1