[PATCH 5.19 074/158] net: Fix a data-race around netdev_budget.

From: Greg Kroah-Hartman
Date: Mon Aug 29 2022 - 07:27:23 EST


From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>

[ 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@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 34282b93c3f60..a330f93629314 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6647,7 +6647,7 @@ 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