diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-12-11 04:55:03 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-06-13 17:12:20 +0300 |
| commit | c78305763b140a426d74c8e937a96ecc76cfd15e (patch) | |
| tree | dfa43d468bacfe05ab7eb2a9692e59f20149b3d9 /net/ipv4 | |
| parent | 4ff12f87c37257ac68b5bfa676409c7b35529168 (diff) | |
| download | linux-c78305763b140a426d74c8e937a96ecc76cfd15e.tar.xz | |
tcp: avoid integer overflows in tcp_rcv_space_adjust()
commit 607065bad9931e72207b0cac365d7d4abc06bd99 upstream.
When using large tcp_rmem[2] values (I did tests with 500 MB),
I noticed overflows while computing rcvwin.
Lets fix this before the following patch.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Wei Wang <weiwan@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[Backport: sysctl_tcp_rmem is not Namespace-ify'd in older kernels]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/tcp_input.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index 7904445338f2..556e23235937 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -550,8 +550,8 @@ static inline void tcp_rcv_rtt_measure_ts(struct sock *sk, void tcp_rcv_space_adjust(struct sock *sk) { struct tcp_sock *tp = tcp_sk(sk); + u32 copied; int time; - int copied; time = tcp_time_stamp - tp->rcvq_space.time; if (time < (tp->rcv_rtt_est.rtt >> 3) || tp->rcv_rtt_est.rtt == 0) @@ -573,12 +573,13 @@ void tcp_rcv_space_adjust(struct sock *sk) if (sysctl_tcp_moderate_rcvbuf && !(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) { - int rcvwin, rcvmem, rcvbuf; + int rcvmem, rcvbuf; + u64 rcvwin; /* minimal window to cope with packet losses, assuming * steady state. Add some cushion because of small variations. */ - rcvwin = (copied << 1) + 16 * tp->advmss; + rcvwin = ((u64)copied << 1) + 16 * tp->advmss; /* If rate increased by 25%, * assume slow start, rcvwin = 3 * copied @@ -598,7 +599,8 @@ void tcp_rcv_space_adjust(struct sock *sk) while (tcp_win_from_space(rcvmem) < tp->advmss) rcvmem += 128; - rcvbuf = min(rcvwin / tp->advmss * rcvmem, sysctl_tcp_rmem[2]); + do_div(rcvwin, tp->advmss); + rcvbuf = min_t(u64, rcvwin * rcvmem, sysctl_tcp_rmem[2]); if (rcvbuf > sk->sk_rcvbuf) { sk->sk_rcvbuf = rcvbuf; |