This is a note to let you know that I've just added the patch titled
icmp: Fix data-races around sysctl.
to the 5.18-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:
icmp-fix-data-races-around-sysctl.patch
and it can be found in the queue-5.18 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit feb9fa400d52c9649704e6721c20e1b5797720d2
Author: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Date: Wed Jul 6 16:40:02 2022 -0700
icmp: Fix data-races around sysctl.
[ 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@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
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.
