From: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
[ 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@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
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
--
2.15.1