From: "Gustavo A. R. Silva" gustavo@embeddedor.com
[ Upstream commit e4823fbd229bfbba368b40cdadb8f4eeb20604cc ]
Add suffix ULL to constant 80000 in order to avoid a potential integer overflow and give the compiler complete information about the proper arithmetic to use. Notice that this constant is used in a context that expects an expression of type u64.
The current cast to u64 effectively applies to the whole expression as an argument of type u64 to be passed to div64_u64, but it does not prevent it from being evaluated using 32-bit arithmetic instead of 64-bit arithmetic.
Also, once the expression is properly evaluated using 64-bit arithmentic, there is no need for the parentheses and the external cast to u64.
Addresses-Coverity-ID: 1357588 ("Unintentional integer overflow") Signed-off-by: Gustavo A. R. Silva gustavo@embeddedor.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- net/ipv4/tcp_nv.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv4/tcp_nv.c b/net/ipv4/tcp_nv.c index 0b5a05bd82e3..d18f4672beae 100644 --- a/net/ipv4/tcp_nv.c +++ b/net/ipv4/tcp_nv.c @@ -364,7 +364,7 @@ static void tcpnv_acked(struct sock *sk, const struct ack_sample *sample) */ cwnd_by_slope = (u32) div64_u64(((u64)ca->nv_rtt_max_rate) * ca->nv_min_rtt, - (u64)(80000 * tp->mss_cache)); + 80000ULL * tp->mss_cache); max_win = cwnd_by_slope + nv_pad;
/* If cwnd > max_win, decrease cwnd