From 73ed8e03388d16c12fc577e5c700b58a29045a15 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 20 Oct 2023 12:57:37 +0000 Subject: tcp: fix cookie_init_timestamp() overflows cookie_init_timestamp() is supposed to return a 64bit timestamp suitable for both TSval determination and setting of skb->tstamp. Unfortunately it uses 32bit fields and overflows after 2^32 * 10^6 nsec (~49 days) of uptime. Generated TSval are still correct, but skb->tstamp might be set far away in the past, potentially confusing other layers. tcp_ns_to_ts() is changed to return a full 64bit value, ts and ts_now variables are changed to u64 type, and TSMASK is removed in favor of shifts operations. While we are at it, change this sequence: ts >>= TSBITS; ts--; ts <<= TSBITS; ts |= options; to: ts -= (1UL << TSBITS); Fixes: 9a568de4818d ("tcp: switch TCP TS option (RFC 7323) to 1ms clock") Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/tcp.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/net/tcp.h') diff --git a/include/net/tcp.h b/include/net/tcp.h index bad304d173a5..d47a57a47b50 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -805,7 +805,7 @@ static inline u32 tcp_time_stamp(const struct tcp_sock *tp) } /* Convert a nsec timestamp into TCP TSval timestamp (ms based currently) */ -static inline u32 tcp_ns_to_ts(u64 ns) +static inline u64 tcp_ns_to_ts(u64 ns) { return div_u64(ns, NSEC_PER_SEC / TCP_TS_HZ); } -- cgit