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 fe10a565b7d8..953cc70851cf 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -266,11 +266,12 @@ 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.