This is a note to let you know that I've just added the patch titled net: Fix a data-race around netdev_budget_usecs. to the 5.15-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_usecs.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 601bf4829aa09491e50f982d85f6ce0ca9f79a68 Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx> Date: Tue Aug 23 10:46:55 2022 -0700 net: Fix a data-race around netdev_budget_usecs. [ Upstream commit fa45d484c52c73f79db2c23b0cdfc6c6455093ad ] While reading netdev_budget_usecs, it can be changed concurrently. Thus, we need to add READ_ONCE() to its reader. Fixes: 7acf8a1e8a28 ("Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning") 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 fefe8ddd282fd..276cca563325e 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -7137,7 +7137,7 @@ 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); + usecs_to_jiffies(READ_ONCE(netdev_budget_usecs)); int budget = READ_ONCE(netdev_budget); LIST_HEAD(list); LIST_HEAD(repoll);