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Subject[PATCH 5.18 079/231] icmp: Fix data-races around sysctl.
Date
From: Kuniyuki Iwashima <kuniyu@amazon.com>

[ Upstream commit 48d7ee321ea5182c6a70782aa186422a70e67e22 ]

While reading icmp sysctl variables, they can be changed concurrently.
So, we need to add READ_ONCE() to avoid data-races.

Fixes: 4cdf507d5452 ("icmp: add a global rate limitation")
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/ipv4/icmp.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index 72a375c7f417..97350a38a75d 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -253,11 +253,12 @@ bool icmp_global_allow(void)
spin_lock(&icmp_global.lock);
delta = min_t(u32, now - icmp_global.stamp, HZ);
if (delta >= HZ / 50) {
- incr = sysctl_icmp_msgs_per_sec * delta / HZ ;
+ incr = READ_ONCE(sysctl_icmp_msgs_per_sec) * delta / HZ;
if (incr)
WRITE_ONCE(icmp_global.stamp, now);
}
- credit = min_t(u32, icmp_global.credit + incr, sysctl_icmp_msgs_burst);
+ credit = min_t(u32, icmp_global.credit + incr,
+ READ_ONCE(sysctl_icmp_msgs_burst));
if (credit) {
/* We want to use a credit of one in average, but need to randomize
* it for security reasons.
--
2.35.1


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