| Message ID | 20170911062338.9825-2-po-hsu.lin@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | [CVE-2017-14106,T/X/Z,SRU] tcp: initialize rcv_mss to TCP_MIN_MSS instead of 0 | expand |
On 11.09.2017 08:23, Po-Hsu Lin wrote: > From: Wei Wang <weiwan@google.com> > > CVE-2017-14106 > > When tcp_disconnect() is called, inet_csk_delack_init() sets > icsk->icsk_ack.rcv_mss to 0. > This could potentially cause tcp_recvmsg() => tcp_cleanup_rbuf() => > __tcp_select_window() call path to have division by 0 issue. > So this patch initializes rcv_mss to TCP_MIN_MSS instead of 0. > > Reported-by: Andrey Konovalov <andreyknvl@google.com> > Signed-off-by: Wei Wang <weiwan@google.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> > Signed-off-by: Neal Cardwell <ncardwell@google.com> > Signed-off-by: Yuchung Cheng <ycheng@google.com> > Signed-off-by: David S. Miller <davem@davemloft.net> > (cherry picked from commit 499350a5a6e7512d9ed369ed63a4244b6536f4f8) > Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> > --- > net/ipv4/tcp.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index 16b5118..46c45a0 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -2202,6 +2202,10 @@ int tcp_disconnect(struct sock *sk, int flags) > tcp_set_ca_state(sk, TCP_CA_Open); > tcp_clear_retrans(tp); > inet_csk_delack_init(sk); > + /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0 > + * issue in __tcp_select_window() > + */ > + icsk->icsk_ack.rcv_mss = TCP_MIN_MSS; > tcp_init_send_head(sk); > memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); > __sk_dst_reset(sk); >
On 11/09/17 07:23, Po-Hsu Lin wrote: > From: Wei Wang <weiwan@google.com> > > CVE-2017-14106 > > When tcp_disconnect() is called, inet_csk_delack_init() sets > icsk->icsk_ack.rcv_mss to 0. > This could potentially cause tcp_recvmsg() => tcp_cleanup_rbuf() => > __tcp_select_window() call path to have division by 0 issue. > So this patch initializes rcv_mss to TCP_MIN_MSS instead of 0. > > Reported-by: Andrey Konovalov <andreyknvl@google.com> > Signed-off-by: Wei Wang <weiwan@google.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> > Signed-off-by: Neal Cardwell <ncardwell@google.com> > Signed-off-by: Yuchung Cheng <ycheng@google.com> > Signed-off-by: David S. Miller <davem@davemloft.net> > (cherry picked from commit 499350a5a6e7512d9ed369ed63a4244b6536f4f8) > Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com> > --- > net/ipv4/tcp.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index 16b5118..46c45a0 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -2202,6 +2202,10 @@ int tcp_disconnect(struct sock *sk, int flags) > tcp_set_ca_state(sk, TCP_CA_Open); > tcp_clear_retrans(tp); > inet_csk_delack_init(sk); > + /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0 > + * issue in __tcp_select_window() > + */ > + icsk->icsk_ack.rcv_mss = TCP_MIN_MSS; > tcp_init_send_head(sk); > memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); > __sk_dst_reset(sk); > Clean cherry pick, looks OK. Acked-by: Colin Ian King <colin.king@canonical.com>
On 11.09.2017 08:23, Po-Hsu Lin wrote: > From: Wei Wang <weiwan@google.com> > > CVE-2017-14106 > > When tcp_disconnect() is called, inet_csk_delack_init() sets > icsk->icsk_ack.rcv_mss to 0. > This could potentially cause tcp_recvmsg() => tcp_cleanup_rbuf() => > __tcp_select_window() call path to have division by 0 issue. > So this patch initializes rcv_mss to TCP_MIN_MSS instead of 0. > > Reported-by: Andrey Konovalov <andreyknvl@google.com> > Signed-off-by: Wei Wang <weiwan@google.com> > Signed-off-by: Eric Dumazet <edumazet@google.com> > Signed-off-by: Neal Cardwell <ncardwell@google.com> > Signed-off-by: Yuchung Cheng <ycheng@google.com> > Signed-off-by: David S. Miller <davem@davemloft.net> > (cherry picked from commit 499350a5a6e7512d9ed369ed63a4244b6536f4f8) > Signed-off-by: Po-Hsu Lin <po-hsu.lin@canonical.com> > --- > net/ipv4/tcp.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index 16b5118..46c45a0 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -2202,6 +2202,10 @@ int tcp_disconnect(struct sock *sk, int flags) > tcp_set_ca_state(sk, TCP_CA_Open); > tcp_clear_retrans(tp); > inet_csk_delack_init(sk); > + /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0 > + * issue in __tcp_select_window() > + */ > + icsk->icsk_ack.rcv_mss = TCP_MIN_MSS; > tcp_init_send_head(sk); > memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); > __sk_dst_reset(sk); > Applied to Trusty, Xenial, and Zesty master-next
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c index 16b5118..46c45a0 100644 --- a/net/ipv4/tcp.c +++ b/net/ipv4/tcp.c @@ -2202,6 +2202,10 @@ int tcp_disconnect(struct sock *sk, int flags) tcp_set_ca_state(sk, TCP_CA_Open); tcp_clear_retrans(tp); inet_csk_delack_init(sk); + /* Initialize rcv_mss to TCP_MIN_MSS to avoid division by 0 + * issue in __tcp_select_window() + */ + icsk->icsk_ack.rcv_mss = TCP_MIN_MSS; tcp_init_send_head(sk); memset(&tp->rx_opt, 0, sizeof(tp->rx_opt)); __sk_dst_reset(sk);