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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2011-07-29 19:00:53 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-08-03 03:34:12 -0700 |
| commit | f2c31e32b378a6653f8de606149d963baf11d7d3 (patch) | |
| tree | 4eeb8075a93520935381a75514f309228e6824c0 /net/ipv6/addrconf.c | |
| parent | 28f4881cbf9ce285edfc245a8990af36d21c062f (diff) | |
| download | linux-3.10-f2c31e32b378a6653f8de606149d963baf11d7d3.tar.gz linux-3.10-f2c31e32b378a6653f8de606149d963baf11d7d3.tar.bz2 linux-3.10-f2c31e32b378a6653f8de606149d963baf11d7d3.zip | |
net: fix NULL dereferences in check_peer_redir()
Gergely Kalman reported crashes in check_peer_redir().
It appears commit f39925dbde778 (ipv4: Cache learned redirect
information in inetpeer.) added a race, leading to possible NULL ptr
dereference.
Since we can now change dst neighbour, we should make sure a reader can
safely use a neighbour.
Add RCU protection to dst neighbour, and make sure check_peer_redir()
can be called safely by different cpus in parallel.
As neighbours are already freed after one RCU grace period, this patch
should not add typical RCU penalty (cache cold effects)
Many thanks to Gergely for providing a pretty report pointing to the
bug.
Reported-by: Gergely Kalman <synapse@hippy.csoma.elte.hu>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/addrconf.c')
| -rw-r--r-- | net/ipv6/addrconf.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c index a55500cc0b2..f012ebd87b4 100644 --- a/net/ipv6/addrconf.c +++ b/net/ipv6/addrconf.c @@ -656,7 +656,7 @@ ipv6_add_addr(struct inet6_dev *idev, const struct in6_addr *addr, int pfxlen, * layer address of our nexhop router */ - if (dst_get_neighbour(&rt->dst) == NULL) + if (dst_get_neighbour_raw(&rt->dst) == NULL) ifa->flags &= ~IFA_F_OPTIMISTIC; ifa->idev = idev; |