diff options
author | Gordon Tetlow <gordon@FreeBSD.org> | 2020-03-19 16:50:36 +0000 |
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committer | Gordon Tetlow <gordon@FreeBSD.org> | 2020-03-19 16:50:36 +0000 |
commit | fcfa8e1efd4ccee4a497806c4eed5c71d2071b4c (patch) | |
tree | f13085eb8be6c4aeb1b24dcc1c22c9c501fe927d | |
parent | 9842ed8859172c3553bc3d833fec8bca73256ea6 (diff) | |
download | src-test2-fcfa8e1efd4ccee4a497806c4eed5c71d2071b4c.tar.gz src-test2-fcfa8e1efd4ccee4a497806c4eed5c71d2071b4c.zip |
Fix incorrect user-controlled pointer use in epair.
Approved by: so
Security: FreeBSD-SA-20:07.epair
Security: CVE-2020-7452
Notes
Notes:
svn path=/releng/12.1/; revision=359141
-rw-r--r-- | sys/net/if_clone.c | 19 | ||||
-rw-r--r-- | sys/net/if_clone.h | 3 | ||||
-rw-r--r-- | sys/net/if_epair.c | 42 |
3 files changed, 35 insertions, 29 deletions
diff --git a/sys/net/if_clone.c b/sys/net/if_clone.c index 6207ff0c037e..acc392ead16a 100644 --- a/sys/net/if_clone.c +++ b/sys/net/if_clone.c @@ -211,6 +211,18 @@ if_clone_create(char *name, size_t len, caddr_t params) return (if_clone_createif(ifc, name, len, params)); } +void +if_clone_addif(struct if_clone *ifc, struct ifnet *ifp) +{ + + if ((ifc->ifc_flags & IFC_NOGROUP) == 0) + if_addgroup(ifp, ifc->ifc_name); + + IF_CLONE_LOCK(ifc); + IFC_IFLIST_INSERT(ifc, ifp); + IF_CLONE_UNLOCK(ifc); +} + /* * Create a clone network interface. */ @@ -233,12 +245,7 @@ if_clone_createif(struct if_clone *ifc, char *name, size_t len, caddr_t params) if (ifp == NULL) panic("%s: lookup failed for %s", __func__, name); - if ((ifc->ifc_flags & IFC_NOGROUP) == 0) - if_addgroup(ifp, ifc->ifc_name); - - IF_CLONE_LOCK(ifc); - IFC_IFLIST_INSERT(ifc, ifp); - IF_CLONE_UNLOCK(ifc); + if_clone_addif(ifc, ifp); } return (err); diff --git a/sys/net/if_clone.h b/sys/net/if_clone.h index 5dceacf68e0f..b721e294119b 100644 --- a/sys/net/if_clone.h +++ b/sys/net/if_clone.h @@ -79,7 +79,8 @@ int if_clone_list(struct if_clonereq *); struct if_clone *if_clone_findifc(struct ifnet *); void if_clone_addgroup(struct ifnet *, struct if_clone *); -/* The below interface used only by epair(4). */ +/* The below interfaces are used only by epair(4). */ +void if_clone_addif(struct if_clone *, struct ifnet *); int if_clone_destroyif(struct if_clone *, struct ifnet *); #endif /* _KERNEL */ diff --git a/sys/net/if_epair.c b/sys/net/if_epair.c index b28fe2b4bd30..376bdbe9117f 100644 --- a/sys/net/if_epair.c +++ b/sys/net/if_epair.c @@ -711,6 +711,21 @@ epair_clone_match(struct if_clone *ifc, const char *name) return (1); } +static void +epair_clone_add(struct if_clone *ifc, struct epair_softc *scb) +{ + struct ifnet *ifp; + uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */ + + ifp = scb->ifp; + /* Copy epairNa etheraddr and change the last byte. */ + memcpy(eaddr, scb->oifp->if_hw_addr, ETHER_ADDR_LEN); + eaddr[5] = 0x0b; + ether_ifattach(ifp, eaddr); + + if_clone_addif(ifc, ifp); +} + static int epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) { @@ -723,24 +738,6 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) uint32_t hash; uint8_t eaddr[ETHER_ADDR_LEN]; /* 00:00:00:00:00:00 */ - /* - * We are abusing params to create our second interface. - * Actually we already created it and called if_clone_create() - * for it to do the official insertion procedure the moment we knew - * it cannot fail anymore. So just do attach it here. - */ - if (params) { - scb = (struct epair_softc *)params; - ifp = scb->ifp; - /* Copy epairNa etheraddr and change the last byte. */ - memcpy(eaddr, scb->oifp->if_hw_addr, ETHER_ADDR_LEN); - eaddr[5] = 0x0b; - ether_ifattach(ifp, eaddr); - /* Correctly set the name for the cloner list. */ - strlcpy(name, ifp->if_xname, len); - return (0); - } - /* Try to see if a special unit was requested. */ error = ifc_name2unit(name, &unit); if (error != 0) @@ -891,10 +888,11 @@ epair_clone_create(struct if_clone *ifc, char *name, size_t len, caddr_t params) if_setsendqready(ifp); /* We need to play some tricks here for the second interface. */ strlcpy(name, epairname, len); - error = if_clone_create(name, len, (caddr_t)scb); - if (error) - panic("%s: if_clone_create() for our 2nd iface failed: %d", - __func__, error); + + /* Correctly set the name for the cloner list. */ + strlcpy(name, scb->ifp->if_xname, len); + epair_clone_add(ifc, scb); + scb->if_qflush = ifp->if_qflush; ifp->if_qflush = epair_qflush; ifp->if_transmit = epair_transmit; |