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| author | David S. Miller <davem@davemloft.net> | 2011-03-10 06:55:25 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-03-10 06:55:25 +0300 |
| commit | 7343ff31ebf01691ea4515d3126467434b9d22d6 (patch) | |
| tree | 13c8180b8aeb82363c1e7b576372c23fa2d5f955 /net/ipv6 | |
| parent | 03a14ab134f4811ab1475f07b1305ccaf38b690f (diff) | |
| download | linux-7343ff31ebf01691ea4515d3126467434b9d22d6.tar.xz | |
ipv6: Don't create clones of host routes.
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=29252
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=30462
In commit d80bc0fd262ef840ed4e82593ad6416fa1ba3fc4 ("ipv6: Always
clone offlink routes.") we forced the kernel to always clone offlink
routes.
The reason we do that is to make sure we never bind an inetpeer to a
prefixed route.
The logic turned on here has existed in the tree for many years,
but was always off due to a protecting CPP define. So perhaps
it's no surprise that there is a logic bug here.
The problem is that we canot clone a route that is already a
host route (ie. has DST_HOST set). Because if we do, an identical
entry already exists in the routing tree and therefore the
ip6_rt_ins() call is going to fail.
This sets off a series of failures and high cpu usage, because when
ip6_rt_ins() fails we loop retrying this operation a few times in
order to handle a race between two threads trying to clone and insert
the same host route at the same time.
Fix this by simply using the route as-is when DST_HOST is set.
Reported-by: slash@ac.auone-net.jp
Reported-by: Ernst Sjöstrand <ernstp@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6')
| -rw-r--r-- | net/ipv6/route.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 904312e25a3c..e7db7014e89f 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -739,8 +739,10 @@ restart: if (!rt->rt6i_nexthop && !(rt->rt6i_flags & RTF_NONEXTHOP)) nrt = rt6_alloc_cow(rt, &fl->fl6_dst, &fl->fl6_src); - else + else if (!(rt->dst.flags & DST_HOST)) nrt = rt6_alloc_clone(rt, &fl->fl6_dst); + else + goto out2; dst_release(&rt->dst); rt = nrt ? : net->ipv6.ip6_null_entry; |