zebra: Fix use after deletion event in freebsd

In the FreeBSD code if you delete the interface
and it has no configuration, the ifp pointer will
be deleted from the system *but* zebra continues
to dereference the just freed pointer.

==58624== Invalid read of size 1
==58624==    at 0x48539F3: strlcpy (in /usr/local/libexec/valgrind/vgpreload_memcheck-amd64-freebsd.so)
==58624==    by 0x2B0565: ifreq_set_name (ioctl.c:48)
==58624==    by 0x2B0565: if_get_flags (ioctl.c:416)
==58624==    by 0x2B2D9E: ifan_read (kernel_socket.c:455)
==58624==    by 0x2B2D9E: kernel_read (kernel_socket.c:1403)
==58624==    by 0x499F46E: thread_call (thread.c:2002)
==58624==    by 0x495D2B7: frr_run (libfrr.c:1196)
==58624==    by 0x2B40B8: main (main.c:471)
==58624==  Address 0x6baa7f0 is 64 bytes inside a block of size 432 free'd
==58624==    at 0x484ECDC: free (in /usr/local/libexec/valgrind/vgpreload_memcheck-amd64-freebsd.so)
==58624==    by 0x4953A64: if_delete (if.c:283)
==58624==    by 0x2A93C1: if_delete_update (interface.c:874)
==58624==    by 0x2B2DF3: ifan_read (kernel_socket.c:453)
==58624==    by 0x2B2DF3: kernel_read (kernel_socket.c:1403)
==58624==    by 0x499F46E: thread_call (thread.c:2002)
==58624==    by 0x495D2B7: frr_run (libfrr.c:1196)
==58624==    by 0x2B40B8: main (main.c:471)
==58624==  Block was alloc'd at
==58624==    at 0x4851381: calloc (in /usr/local/libexec/valgrind/vgpreload_memcheck-amd64-freebsd.so)
==58624==    by 0x496A022: qcalloc (memory.c:116)
==58624==    by 0x49546BC: if_new (if.c:164)
==58624==    by 0x49546BC: if_create_name (if.c:218)
==58624==    by 0x49546BC: if_get_by_name (if.c:603)
==58624==    by 0x2B1295: ifm_read (kernel_socket.c:628)
==58624==    by 0x2A7FB6: interface_list (if_sysctl.c:129)
==58624==    by 0x2E99C8: zebra_ns_enable (zebra_ns.c:127)
==58624==    by 0x2E99C8: zebra_ns_init (zebra_ns.c:214)
==58624==    by 0x2B3FF2: main (main.c:401)
==58624==

Zebra needs to pass back whether or not the ifp pointer
was freed when if_delete_update is called and it should
then check in ifan_read as well as ifm_read that the
ifp pointer is still valid for use.

Signed-off-by: Donald Sharp <sharpd@nvidia.com>
This commit is contained in:
Donald Sharp 2022-03-24 20:02:33 -04:00
parent b15250ccfd
commit d0438da6b0
5 changed files with 22 additions and 18 deletions

View File

@ -103,7 +103,7 @@ static void set_ifindex(struct interface *ifp, ifindex_t ifi_index,
EC_LIB_INTERFACE,
"interface rename detected on up interface: index %d was renamed from %s to %s, results are uncertain!",
ifi_index, oifp->name, ifp->name);
if_delete_update(oifp);
if_delete_update(&oifp);
}
}
if_set_index(ifp, ifi_index);
@ -2144,7 +2144,7 @@ int netlink_link_change(struct nlmsghdr *h, ns_id_t ns_id, int startup)
else if (IS_ZEBRA_IF_VXLAN(ifp))
zebra_l2_vxlanif_del(ifp);
if_delete_update(ifp);
if_delete_update(&ifp);
/* If VRF, delete the VRF structure itself. */
if (zif_type == ZEBRA_IF_VRF && !vrf_is_backend_netns())

View File

@ -806,9 +806,10 @@ static void if_delete_connected(struct interface *ifp)
}
/* Handle an interface delete event */
void if_delete_update(struct interface *ifp)
void if_delete_update(struct interface **pifp)
{
struct zebra_if *zif;
struct interface *ifp = *pifp;
if (if_is_up(ifp)) {
flog_err(
@ -871,7 +872,7 @@ void if_delete_update(struct interface *ifp)
if (IS_ZEBRA_DEBUG_KERNEL)
zlog_debug("interface %s is being deleted from the system",
ifp->name);
if_delete(&ifp);
if_delete(pifp);
}
}

View File

@ -492,7 +492,7 @@ extern void if_nbr_ipv6ll_to_ipv4ll_neigh_update(struct interface *ifp,
struct in6_addr *address,
int add);
extern void if_nbr_ipv6ll_to_ipv4ll_neigh_del_all(struct interface *ifp);
extern void if_delete_update(struct interface *ifp);
extern void if_delete_update(struct interface **ifp);
extern void if_add_update(struct interface *ifp);
extern void if_up(struct interface *ifp, bool install_connected);
extern void if_down(struct interface *);

View File

@ -450,12 +450,13 @@ static int ifan_read(struct if_announcemsghdr *ifan)
if_get_metric(ifp);
if_add_update(ifp);
} else if (ifp != NULL && ifan->ifan_what == IFAN_DEPARTURE)
if_delete_update(ifp);
if_get_flags(ifp);
if_get_mtu(ifp);
if_get_metric(ifp);
if_delete_update(&ifp);
if (ifp) {
if_get_flags(ifp);
if_get_mtu(ifp);
if_get_metric(ifp);
}
if (IS_ZEBRA_DEBUG_KERNEL)
zlog_debug("%s: interface %s index %d", __func__,
ifan->ifan_name, ifan->ifan_index);
@ -722,10 +723,10 @@ int ifm_read(struct if_msghdr *ifm)
* will still behave correctly if run on a platform
* without
*/
if_delete_update(ifp);
if_delete_update(&ifp);
}
#endif /* RTM_IFANNOUNCE */
if (if_is_up(ifp)) {
if (ifp && if_is_up(ifp)) {
#if defined(__bsdi__)
if_kvm_get_mtu(ifp);
#else
@ -735,14 +736,16 @@ int ifm_read(struct if_msghdr *ifm)
}
}
if (ifp) {
#ifdef HAVE_NET_RT_IFLIST
ifp->stats = ifm->ifm_data;
ifp->stats = ifm->ifm_data;
#endif /* HAVE_NET_RT_IFLIST */
ifp->speed = ifm->ifm_data.ifi_baudrate / 1000000;
ifp->speed = ifm->ifm_data.ifi_baudrate / 1000000;
if (IS_ZEBRA_DEBUG_KERNEL)
zlog_debug("%s: interface %s index %d", __func__, ifp->name,
ifp->ifindex);
if (IS_ZEBRA_DEBUG_KERNEL)
zlog_debug("%s: interface %s index %d", __func__,
ifp->name, ifp->ifindex);
}
return 0;
}

View File

@ -179,7 +179,7 @@ static int zebra_ns_delete(char *name)
}
UNSET_FLAG(ifp->flags, IFF_UP);
if_delete_update(ifp);
if_delete_update(&ifp);
}
ns = (struct ns *)vrf->ns_ctxt;