Fix ifa refcount leak in ifa_ifwithnet()
In 4f6c66cc9c
, ifa_ifwithnet() was changed to no longer
ifa_ref() the returned ifaddr, and instead the caller was required
to stay in the net_epoch for as long as they wanted the ifaddr
to remain valid. However, this missed the case where an AF_LINK
lookup would call ifaddr_byindex(), which still does ifa_ref()
the ifaddr. This would cause a refcount leak.
Fix this by inlining the relevant parts of ifaddr_byindex() here,
with the ifa_ref() call removed. This also avoids an unnecessary
entry and exit from the net_epoch for this case.
I've audited all in-tree consumers of ifa_ifwithnet() that could
possibly perform an AF_LINK lookup and confirmed that none of them
will expect the ifaddr to have a reference that they need to
release.
MFC after: 2 months
Sponsored by: Dell Inc
Differential Revision: https://reviews.freebsd.org/D28705
Reviewed by: melifaro
This commit is contained in:
parent
32a95656b5
commit
5adea417d4
12
sys/net/if.c
12
sys/net/if.c
@ -1953,6 +1953,7 @@ ifa_ifwithnet(const struct sockaddr *addr, int ignore_ptp, int fibnum)
|
|||||||
struct ifaddr *ifa_maybe = NULL;
|
struct ifaddr *ifa_maybe = NULL;
|
||||||
u_int af = addr->sa_family;
|
u_int af = addr->sa_family;
|
||||||
const char *addr_data = addr->sa_data, *cplim;
|
const char *addr_data = addr->sa_data, *cplim;
|
||||||
|
const struct sockaddr_dl *sdl;
|
||||||
|
|
||||||
NET_EPOCH_ASSERT();
|
NET_EPOCH_ASSERT();
|
||||||
/*
|
/*
|
||||||
@ -1960,9 +1961,14 @@ ifa_ifwithnet(const struct sockaddr *addr, int ignore_ptp, int fibnum)
|
|||||||
* so do that if we can.
|
* so do that if we can.
|
||||||
*/
|
*/
|
||||||
if (af == AF_LINK) {
|
if (af == AF_LINK) {
|
||||||
const struct sockaddr_dl *sdl = (const struct sockaddr_dl *)addr;
|
sdl = (const struct sockaddr_dl *)addr;
|
||||||
if (sdl->sdl_index && sdl->sdl_index <= V_if_index)
|
if (sdl->sdl_index && sdl->sdl_index <= V_if_index) {
|
||||||
return (ifaddr_byindex(sdl->sdl_index));
|
ifp = ifnet_byindex(sdl->sdl_index);
|
||||||
|
if (ifp == NULL)
|
||||||
|
return (NULL);
|
||||||
|
|
||||||
|
return (ifp->if_addr);
|
||||||
|
}
|
||||||
}
|
}
|
||||||
|
|
||||||
/*
|
/*
|
||||||
|
Loading…
Reference in New Issue
Block a user