From d25f8522beb8a7f198dc175b7a39dde18127d419 Mon Sep 17 00:00:00 2001 From: Mark Johnston Date: Mon, 26 Nov 2018 13:42:18 +0000 Subject: [PATCH] Plug routing sysctl leaks. Various structures exported by sysctl_rtsock() contain padding fields which were not being zeroed. Reported by: Thomas Barabosch, Fraunhofer FKIE Reviewed by: ae MFC after: 3 days Security: kernel memory disclosure Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D18333 --- sys/net/if.h | 4 ++++ sys/net/route.h | 1 + sys/net/rtsock.c | 16 ++++++++++++++-- 3 files changed, 19 insertions(+), 2 deletions(-) diff --git a/sys/net/if.h b/sys/net/if.h index 1c860ffedbdf..d6e032e36f7b 100644 --- a/sys/net/if.h +++ b/sys/net/if.h @@ -271,6 +271,7 @@ struct if_msghdr { int ifm_addrs; /* like rtm_addrs */ int ifm_flags; /* value of if_flags */ u_short ifm_index; /* index for associated ifp */ + u_short _ifm_spare1; struct if_data ifm_data;/* statistics and other data about if */ }; @@ -296,6 +297,7 @@ struct if_msghdrl { u_short _ifm_spare1; /* spare space to grow if_index, see if_var.h */ u_short ifm_len; /* length of if_msghdrl incl. if_data */ u_short ifm_data_off; /* offset of if_data from beginning */ + int _ifm_spare2; struct if_data ifm_data;/* statistics and other data about if */ }; @@ -311,6 +313,7 @@ struct ifa_msghdr { int ifam_addrs; /* like rtm_addrs */ int ifam_flags; /* value of ifa_flags */ u_short ifam_index; /* index for associated ifp */ + u_short _ifam_spare1; int ifam_metric; /* value of ifa_ifp->if_metric */ }; @@ -352,6 +355,7 @@ struct ifma_msghdr { int ifmam_addrs; /* like rtm_addrs */ int ifmam_flags; /* value of ifa_flags */ u_short ifmam_index; /* index for associated ifp */ + u_short _ifmam_spare1; }; /* diff --git a/sys/net/route.h b/sys/net/route.h index 15ec1b3e9a38..c4333838e9af 100644 --- a/sys/net/route.h +++ b/sys/net/route.h @@ -251,6 +251,7 @@ struct rt_msghdr { u_char rtm_version; /* future binary compatibility */ u_char rtm_type; /* message type */ u_short rtm_index; /* index for associated ifp */ + u_short _rtm_spare1; int rtm_flags; /* flags, incl. kern & message, e.g. DONE */ int rtm_addrs; /* bitmask identifying sockaddrs in msg */ pid_t rtm_pid; /* identify sender */ diff --git a/sys/net/rtsock.c b/sys/net/rtsock.c index 407764ed263f..06cd77f4836f 100644 --- a/sys/net/rtsock.c +++ b/sys/net/rtsock.c @@ -83,6 +83,7 @@ struct if_msghdr32 { int32_t ifm_addrs; int32_t ifm_flags; uint16_t ifm_index; + uint16_t _ifm_spare1; struct if_data ifm_data; }; @@ -96,6 +97,7 @@ struct if_msghdrl32 { uint16_t _ifm_spare1; uint16_t ifm_len; uint16_t ifm_data_off; + uint32_t _ifm_spare2; struct if_data ifm_data; }; @@ -1219,8 +1221,11 @@ rtsock_msg_buffer(int type, struct rt_addrinfo *rtinfo, struct walkarg *w, int * dlen = ALIGN(len) - len; if (buflen < dlen) cp = NULL; - else + else { + bzero(cp, dlen); + cp += dlen; buflen -= dlen; + } } len = ALIGN(len); @@ -1577,6 +1582,8 @@ sysctl_dumpentry(struct radix_node *rn, void *vw) if (w->w_req && w->w_tmem) { struct rt_msghdr *rtm = (struct rt_msghdr *)w->w_tmem; + bzero(&rtm->rtm_index, + sizeof(*rtm) - offsetof(struct rt_msghdr, rtm_index)); if (rt->rt_flags & RTF_GWFLAG_COMPAT) rtm->rtm_flags = RTF_GATEWAY | (rt->rt_flags & ~RTF_GWFLAG_COMPAT); @@ -1584,7 +1591,6 @@ sysctl_dumpentry(struct radix_node *rn, void *vw) rtm->rtm_flags = rt->rt_flags; rt_getmetrics(rt, &rtm->rtm_rmx); rtm->rtm_index = rt->rt_ifp->if_index; - rtm->rtm_errno = rtm->rtm_pid = rtm->rtm_seq = 0; rtm->rtm_addrs = info.rti_addrs; error = SYSCTL_OUT(w->w_req, (caddr_t)rtm, size); return (error); @@ -1612,6 +1618,7 @@ sysctl_iflist_ifml(struct ifnet *ifp, const struct if_data *src_ifd, ifm32->_ifm_spare1 = 0; ifm32->ifm_len = sizeof(*ifm32); ifm32->ifm_data_off = offsetof(struct if_msghdrl32, ifm_data); + ifm32->_ifm_spare2 = 0; ifd = &ifm32->ifm_data; } else #endif @@ -1622,6 +1629,7 @@ sysctl_iflist_ifml(struct ifnet *ifp, const struct if_data *src_ifd, ifm->_ifm_spare1 = 0; ifm->ifm_len = sizeof(*ifm); ifm->ifm_data_off = offsetof(struct if_msghdrl, ifm_data); + ifm->_ifm_spare2 = 0; ifd = &ifm->ifm_data; } @@ -1647,6 +1655,7 @@ sysctl_iflist_ifm(struct ifnet *ifp, const struct if_data *src_ifd, ifm32->ifm_addrs = info->rti_addrs; ifm32->ifm_flags = ifp->if_flags | ifp->if_drv_flags; ifm32->ifm_index = ifp->if_index; + ifm32->_ifm_spare1 = 0; ifd = &ifm32->ifm_data; } else #endif @@ -1654,6 +1663,7 @@ sysctl_iflist_ifm(struct ifnet *ifp, const struct if_data *src_ifd, ifm->ifm_addrs = info->rti_addrs; ifm->ifm_flags = ifp->if_flags | ifp->if_drv_flags; ifm->ifm_index = ifp->if_index; + ifm->_ifm_spare1 = 0; ifd = &ifm->ifm_data; } @@ -1722,6 +1732,7 @@ sysctl_iflist_ifam(struct ifaddr *ifa, struct rt_addrinfo *info, ifam->ifam_addrs = info->rti_addrs; ifam->ifam_flags = ifa->ifa_flags; ifam->ifam_index = ifa->ifa_ifp->if_index; + ifam->_ifam_spare1 = 0; ifam->ifam_metric = ifa->ifa_ifp->if_metric; return (SYSCTL_OUT(w->w_req, w->w_tmem, len)); @@ -1833,6 +1844,7 @@ sysctl_ifmalist(int af, struct walkarg *w) ifmam->ifmam_index = ifma->ifma_ifp->if_index; ifmam->ifmam_flags = 0; ifmam->ifmam_addrs = info.rti_addrs; + ifmam->_ifmam_spare1 = 0; error = SYSCTL_OUT(w->w_req, w->w_tmem, len); if (error != 0) break;