This is a note to let you know that I've just added the patch titled
net: Fix a data-race around netdev_budget.
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
net-fix-a-data-race-around-netdev_budget.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ad9b68f64b87f3c534e7403e9801f812d93f2cee
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Tue Aug 23 10:46:53 2022 -0700
net: Fix a data-race around netdev_budget.
[ 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>
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);
