From: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
[ Upstream commit 2afdbe7b8de84c28e219073a6661080e1b3ded48 ]
While reading sysctl_tcp_invalid_ratelimit, it can be changed
concurrently. Thus, we need to add READ_ONCE() to its reader.
Fixes: 032ee4236954 ("tcp: helpers to mitigate ACK loops by rate-limiting out-of-window dupacks")
Signed-off-by: Kuniyuki Iwashima <kuniyu@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv4/tcp_input.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 04788bd5e82c..38412d93400a 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -3420,7 +3420,8 @@ static bool __tcp_oow_rate_limited(struct net *net, int mib_idx,
if (*last_oow_ack_time) {
s32 elapsed = (s32)(tcp_jiffies32 - *last_oow_ack_time);
- if (0 <= elapsed && elapsed < net->ipv4.sysctl_tcp_invalid_ratelimit) {
+ if (0 <= elapsed &&
+ elapsed < READ_ONCE(net->ipv4.sysctl_tcp_invalid_ratelimit)) {
NET_INC_STATS(net, mib_idx);
return true; /* rate-limited: don't send yet! */
}
--
2.35.1
