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authorGordon Tetlow <gordon@FreeBSD.org>2018-09-27 18:34:42 +0000
committerGordon Tetlow <gordon@FreeBSD.org>2018-09-27 18:34:42 +0000
commit8c743a4ed41b46ec72e47b8d4e1364d56ceba9b3 (patch)
tree632634ed30077353823f918131a16ccdc744cd11
parent50120a8199f7bd256bda59218f4090031a4561fe (diff)
downloadsrc-8c743a4ed41b46ec72e47b8d4e1364d56ceba9b3.tar.gz
src-8c743a4ed41b46ec72e47b8d4e1364d56ceba9b3.zip
Fix DoS in listen syscall over IPv6 socket. [EN-18:11.listen]
Reported by: Jakub Jirasek, Secunia Research at Flexera Approved by: so Security: FreeBSD-EN-18:11.listen Security: CVE-2018-6925
Notes
Notes: svn path=/releng/11.1/; revision=338980
-rw-r--r--sys/netinet/tcp_usrreq.c30
-rw-r--r--sys/netinet6/sctp6_usrreq.c13
-rw-r--r--sys/netinet6/udp6_usrreq.c31
3 files changed, 63 insertions, 11 deletions
diff --git a/sys/netinet/tcp_usrreq.c b/sys/netinet/tcp_usrreq.c
index 64f8562c7b2f..2ad2c514251a 100644
--- a/sys/netinet/tcp_usrreq.c
+++ b/sys/netinet/tcp_usrreq.c
@@ -339,6 +339,7 @@ tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
struct inpcb *inp;
struct tcpcb *tp = NULL;
struct sockaddr_in6 *sin6p;
+ u_char vflagsav;
sin6p = (struct sockaddr_in6 *)nam;
if (nam->sa_len != sizeof (*sin6p))
@@ -355,6 +356,7 @@ tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp6_usr_bind: inp == NULL"));
INP_WLOCK(inp);
+ vflagsav = inp->inp_vflag;
if (inp->inp_flags & (INP_TIMEWAIT | INP_DROPPED)) {
error = EINVAL;
goto out;
@@ -384,6 +386,8 @@ tcp6_usr_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
error = in6_pcbbind(inp, nam, td->td_ucred);
INP_HASH_WUNLOCK(&V_tcbinfo);
out:
+ if (error != 0)
+ inp->inp_vflag = vflagsav;
TCPDEBUG2(PRU_BIND);
TCP_PROBE2(debug__user, tp, PRU_BIND);
INP_WUNLOCK(inp);
@@ -447,6 +451,7 @@ tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
int error = 0;
struct inpcb *inp;
struct tcpcb *tp = NULL;
+ u_char vflagsav;
TCPDEBUG0;
inp = sotoinpcb(so);
@@ -456,6 +461,7 @@ tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
error = EINVAL;
goto out;
}
+ vflagsav = inp->inp_vflag;
tp = intotcpcb(inp);
TCPDEBUG1();
SOCK_LOCK(so);
@@ -482,6 +488,9 @@ tcp6_usr_listen(struct socket *so, int backlog, struct thread *td)
if (tp->t_flags & TF_FASTOPEN)
tp->t_tfo_pending = tcp_fastopen_alloc_counter();
#endif
+ if (error != 0)
+ inp->inp_vflag = vflagsav;
+
out:
TCPDEBUG2(PRU_LISTEN);
TCP_PROBE2(debug__user, tp, PRU_LISTEN);
@@ -558,6 +567,8 @@ tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
struct inpcb *inp;
struct tcpcb *tp = NULL;
struct sockaddr_in6 *sin6p;
+ u_int8_t incflagsav;
+ u_char vflagsav;
TCPDEBUG0;
@@ -574,6 +585,8 @@ tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
inp = sotoinpcb(so);
KASSERT(inp != NULL, ("tcp6_usr_connect: inp == NULL"));
INP_WLOCK(inp);
+ vflagsav = inp->inp_vflag;
+ incflagsav = inp->inp_inc.inc_flags;
if (inp->inp_flags & INP_TIMEWAIT) {
error = EADDRINUSE;
goto out;
@@ -603,11 +616,11 @@ tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
}
in6_sin6_2_sin(&sin, sin6p);
- inp->inp_vflag |= INP_IPV4;
- inp->inp_vflag &= ~INP_IPV6;
if ((error = prison_remote_ip4(td->td_ucred,
&sin.sin_addr)) != 0)
goto out;
+ inp->inp_vflag |= INP_IPV4;
+ inp->inp_vflag &= ~INP_IPV6;
if ((error = tcp_connect(tp, (struct sockaddr *)&sin, td)) != 0)
goto out;
#ifdef TCP_OFFLOAD
@@ -625,11 +638,11 @@ tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
}
}
#endif
+ if ((error = prison_remote_ip6(td->td_ucred, &sin6p->sin6_addr)) != 0)
+ goto out;
inp->inp_vflag &= ~INP_IPV4;
inp->inp_vflag |= INP_IPV6;
inp->inp_inc.inc_flags |= INC_ISIPV6;
- if ((error = prison_remote_ip6(td->td_ucred, &sin6p->sin6_addr)) != 0)
- goto out;
if ((error = tcp6_connect(tp, nam, td)) != 0)
goto out;
#ifdef TCP_OFFLOAD
@@ -642,6 +655,15 @@ tcp6_usr_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
error = tp->t_fb->tfb_tcp_output(tp);
out:
+ /*
+ * If the implicit bind in the connect call fails, restore
+ * the flags we modified.
+ */
+ if (error != 0 && inp->inp_lport == 0) {
+ inp->inp_vflag = vflagsav;
+ inp->inp_inc.inc_flags = incflagsav;
+ }
+
TCPDEBUG2(PRU_CONNECT);
TCP_PROBE2(debug__user, tp, PRU_CONNECT);
INP_WUNLOCK(inp);
diff --git a/sys/netinet6/sctp6_usrreq.c b/sys/netinet6/sctp6_usrreq.c
index 054b4c1b06a5..a3e69d8d782d 100644
--- a/sys/netinet6/sctp6_usrreq.c
+++ b/sys/netinet6/sctp6_usrreq.c
@@ -561,6 +561,7 @@ sctp6_bind(struct socket *so, struct sockaddr *addr, struct thread *p)
struct sctp_inpcb *inp;
struct in6pcb *inp6;
int error;
+ u_char vflagsav;
inp = (struct sctp_inpcb *)so->so_pcb;
if (inp == NULL) {
@@ -591,6 +592,7 @@ sctp6_bind(struct socket *so, struct sockaddr *addr, struct thread *p)
}
}
inp6 = (struct in6pcb *)inp;
+ vflagsav = inp6->inp_vflag;
inp6->inp_vflag &= ~INP_IPV4;
inp6->inp_vflag |= INP_IPV6;
if ((addr != NULL) && (SCTP_IPV6_V6ONLY(inp6) == 0)) {
@@ -620,7 +622,7 @@ sctp6_bind(struct socket *so, struct sockaddr *addr, struct thread *p)
inp6->inp_vflag |= INP_IPV4;
inp6->inp_vflag &= ~INP_IPV6;
error = sctp_inpcb_bind(so, (struct sockaddr *)&sin, NULL, p);
- return (error);
+ goto out;
}
#endif
break;
@@ -637,7 +639,8 @@ sctp6_bind(struct socket *so, struct sockaddr *addr, struct thread *p)
if (addr->sa_family == AF_INET) {
/* can't bind v4 addr to v6 only socket! */
SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
- return (EINVAL);
+ error = EINVAL;
+ goto out;
}
#endif
sin6_p = (struct sockaddr_in6 *)addr;
@@ -646,10 +649,14 @@ sctp6_bind(struct socket *so, struct sockaddr *addr, struct thread *p)
/* can't bind v4-mapped addrs either! */
/* NOTE: we don't support SIIT */
SCTP_LTRACE_ERR_RET(inp, NULL, NULL, SCTP_FROM_SCTP6_USRREQ, EINVAL);
- return (EINVAL);
+ error = EINVAL;
+ goto out;
}
}
error = sctp_inpcb_bind(so, addr, NULL, p);
+out:
+ if (error != 0)
+ inp6->inp_vflag = vflagsav;
return (error);
}
diff --git a/sys/netinet6/udp6_usrreq.c b/sys/netinet6/udp6_usrreq.c
index 56faf5a85159..b410f3f30247 100644
--- a/sys/netinet6/udp6_usrreq.c
+++ b/sys/netinet6/udp6_usrreq.c
@@ -1006,6 +1006,7 @@ udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
struct inpcb *inp;
struct inpcbinfo *pcbinfo;
int error;
+ u_char vflagsav;
pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
inp = sotoinpcb(so);
@@ -1013,6 +1014,7 @@ udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
INP_WLOCK(inp);
INP_HASH_WLOCK(pcbinfo);
+ vflagsav = inp->inp_vflag;
inp->inp_vflag &= ~INP_IPV4;
inp->inp_vflag |= INP_IPV6;
if ((inp->inp_flags & IN6P_IPV6_V6ONLY) == 0) {
@@ -1040,6 +1042,8 @@ udp6_bind(struct socket *so, struct sockaddr *nam, struct thread *td)
#ifdef INET
out:
#endif
+ if (error != 0)
+ inp->inp_vflag = vflagsav;
INP_HASH_WUNLOCK(pcbinfo);
INP_WUNLOCK(inp);
return (error);
@@ -1086,6 +1090,7 @@ udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
struct inpcbinfo *pcbinfo;
struct sockaddr_in6 *sin6;
int error;
+ u_char vflagsav;
pcbinfo = udp_get_inpcbinfo(so->so_proto->pr_protocol);
inp = sotoinpcb(so);
@@ -1113,17 +1118,26 @@ udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
goto out;
}
in6_sin6_2_sin(&sin, sin6);
- inp->inp_vflag |= INP_IPV4;
- inp->inp_vflag &= ~INP_IPV6;
error = prison_remote_ip4(td->td_ucred, &sin.sin_addr);
if (error != 0)
goto out;
+ vflagsav = inp->inp_vflag;
+ inp->inp_vflag |= INP_IPV4;
+ inp->inp_vflag &= ~INP_IPV6;
INP_HASH_WLOCK(pcbinfo);
error = in_pcbconnect(inp, (struct sockaddr *)&sin,
td->td_ucred);
INP_HASH_WUNLOCK(pcbinfo);
+ /*
+ * If connect succeeds, mark socket as connected. If
+ * connect fails and socket is unbound, reset inp_vflag
+ * field.
+ */
if (error == 0)
soisconnected(so);
+ else if (inp->inp_laddr.s_addr == INADDR_ANY &&
+ inp->inp_lport == 0)
+ inp->inp_vflag = vflagsav;
goto out;
} else {
if ((inp->inp_vflag & INP_IPV6) == 0) {
@@ -1136,16 +1150,25 @@ udp6_connect(struct socket *so, struct sockaddr *nam, struct thread *td)
error = EISCONN;
goto out;
}
- inp->inp_vflag &= ~INP_IPV4;
- inp->inp_vflag |= INP_IPV6;
error = prison_remote_ip6(td->td_ucred, &sin6->sin6_addr);
if (error != 0)
goto out;
+ vflagsav = inp->inp_vflag;
+ inp->inp_vflag &= ~INP_IPV4;
+ inp->inp_vflag |= INP_IPV6;
INP_HASH_WLOCK(pcbinfo);
error = in6_pcbconnect(inp, nam, td->td_ucred);
INP_HASH_WUNLOCK(pcbinfo);
+ /*
+ * If connect succeeds, mark socket as connected. If
+ * connect fails and socket is unbound, reset inp_vflag
+ * field.
+ */
if (error == 0)
soisconnected(so);
+ else if (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) &&
+ inp->inp_lport == 0)
+ inp->inp_vflag = vflagsav;
out:
INP_WUNLOCK(inp);
return (error);