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| author | David S. Miller <davem@davemloft.net> | 2012-06-11 04:13:57 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-06-11 04:13:57 -0700 |
| commit | 7b34ca2ac7063f4ebf07f85fd75253ed84d5c648 (patch) | |
| tree | 639e89875cd047bb461ab61348050586ceca56b2 | |
| parent | 8b96d22d7a6ec999ae53ae86d829137503ceda65 (diff) | |
| download | blackbird-op-linux-7b34ca2ac7063f4ebf07f85fd75253ed84d5c648.tar.gz blackbird-op-linux-7b34ca2ac7063f4ebf07f85fd75253ed84d5c648.zip | |
inet: Avoid potential NULL peer dereference.
We handle NULL in rt{,6}_set_peer but then our caller will try to pass
that NULL pointer into inet_putpeer() which isn't ready for it.
Fix this by moving the NULL check one level up, and then remove the
now unnecessary NULL check from inetpeer_ptr_set_peer().
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/inetpeer.h | 2 | ||||
| -rw-r--r-- | net/ipv4/route.c | 11 | ||||
| -rw-r--r-- | net/ipv6/route.c | 10 |
3 files changed, 13 insertions, 10 deletions
diff --git a/include/net/inetpeer.h b/include/net/inetpeer.h index e15c0862a686..c27c8f10ebdc 100644 --- a/include/net/inetpeer.h +++ b/include/net/inetpeer.h @@ -104,7 +104,7 @@ static inline bool inetpeer_ptr_set_peer(unsigned long *ptr, struct inet_peer *p unsigned long val = (unsigned long) peer; unsigned long orig = *ptr; - if (!(orig & INETPEER_BASE_BIT) || !val || + if (!(orig & INETPEER_BASE_BIT) || cmpxchg(ptr, orig, val) != orig) return false; return true; diff --git a/net/ipv4/route.c b/net/ipv4/route.c index 4c33ce3000ed..842510d50453 100644 --- a/net/ipv4/route.c +++ b/net/ipv4/route.c @@ -1333,11 +1333,12 @@ void rt_bind_peer(struct rtable *rt, __be32 daddr, int create) return; peer = inet_getpeer_v4(base, daddr, create); - - if (!rt_set_peer(rt, peer)) - inet_putpeer(peer); - else - rt->rt_peer_genid = rt_peer_genid(); + if (peer) { + if (!rt_set_peer(rt, peer)) + inet_putpeer(peer); + else + rt->rt_peer_genid = rt_peer_genid(); + } } /* diff --git a/net/ipv6/route.c b/net/ipv6/route.c index d9ba4808f26a..58a3ec23da2f 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -313,10 +313,12 @@ void rt6_bind_peer(struct rt6_info *rt, int create) return; peer = inet_getpeer_v6(base, &rt->rt6i_dst.addr, create); - if (!rt6_set_peer(rt, peer)) - inet_putpeer(peer); - else - rt->rt6i_peer_genid = rt6_peer_genid(); + if (peer) { + if (!rt6_set_peer(rt, peer)) + inet_putpeer(peer); + else + rt->rt6i_peer_genid = rt6_peer_genid(); + } } static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev, |
