current/SOURCES/net-fix-a-data-race-around-netdev_budget.patch

From b33f86643b2928077ff7c409c9da2979aa300837 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Tue, 23 Aug 2022 10:46:53 -0700
Subject: net: Fix a data-race around netdev_budget.

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 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

1	From b33f86643b2928077ff7c409c9da2979aa300837 Mon Sep 17 00:00:00 2001
2	From: Sasha Levin <sashal@kernel.org>
3	Date: Tue, 23 Aug 2022 10:46:53 -0700
4	Subject: net: Fix a data-race around netdev_budget.
5
6	From: Kuniyuki Iwashima <kuniyu@amazon.com>
7
8	[ Upstream commit 2e0c42374ee32e72948559d2ae2f7ba3dc6b977c ]
9
10	While reading netdev_budget, it can be changed concurrently.
11	Thus, we need to add READ_ONCE() to its reader.
12
13	Fixes: 51b0bdedb8e7 ("[NET]: Separate two usages of netdev_max_backlog.")
14	Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
15	Signed-off-by: David S. Miller <davem@davemloft.net>
16	Signed-off-by: Sasha Levin <sashal@kernel.org>
17	---
18	net/core/dev.c \| 2 +-
19	1 file changed, 1 insertion(+), 1 deletion(-)
20
21	diff --git a/net/core/dev.c b/net/core/dev.c
22	index 34282b93c3f60..a330f93629314 100644
23	--- a/net/core/dev.c
24	+++ b/net/core/dev.c
25	@@ -6647,7 +6647,7 @@ static __latent_entropy void net_rx_action(struct softirq_action *h)
26	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
27	unsigned long time_limit = jiffies +
28	usecs_to_jiffies(netdev_budget_usecs);
29	- int budget = netdev_budget;
30	+ int budget = READ_ONCE(netdev_budget);
31	LIST_HEAD(list);
32	LIST_HEAD(repoll);
33
34	--
35	2.35.1
36