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net: dccp: initialize (addr,port) listening hashtable
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Commit d9fbc7f "net: tcp: prefer listeners bound to an address"
removes port-only listener lookups. This caused segfaults in DCCP
lookups because DCCP did not initialize the (addr,port) hashtable.

This patch adds said initialization.

The only non-trivial issue here is the size of the new hashtable.
It seemed reasonable to make it match the size of the port-only
hashtable (= INET_LHTABLE_SIZE) that was used previously. Other
parameters to inet_hashinfo2_init() match those used in TCP.

V2 changes: marked inet_hashinfo2_init as an exported symbol
so that DCCP compiles when configured as a module.

Tested: syzcaller issues fixed; the second patch in the patchset
        tests that DCCP lookups work correctly.

Fixes: d9fbc7f "net: tcp: prefer listeners bound to an address"
Reported-by: syzcaller <syzkaller@googlegroups.com>
Signed-off-by: Peter Oskolkov <posk@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Peter Oskolkov authored and David S. Miller committed Dec 18, 2018
1 parent 6a95147 commit eedbbb0
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3 changes: 3 additions & 0 deletions net/dccp/proto.c
Original file line number Diff line number Diff line change
Expand Up @@ -1141,6 +1141,9 @@ static int __init dccp_init(void)
goto out_fail;
rc = -ENOBUFS;
inet_hashinfo_init(&dccp_hashinfo);
inet_hashinfo2_init(&dccp_hashinfo, "dccp_listen_portaddr_hash",
INET_LHTABLE_SIZE, 21, /* one slot per 2 MB*/
0, 64 * 1024);
dccp_hashinfo.bind_bucket_cachep =
kmem_cache_create("dccp_bind_bucket",
sizeof(struct inet_bind_bucket), 0,
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1 change: 1 addition & 0 deletions net/ipv4/inet_hashtables.c
Original file line number Diff line number Diff line change
Expand Up @@ -785,6 +785,7 @@ void __init inet_hashinfo2_init(struct inet_hashinfo *h, const char *name,
h->lhash2[i].count = 0;
}
}
EXPORT_SYMBOL_GPL(inet_hashinfo2_init);

int inet_ehash_locks_alloc(struct inet_hashinfo *hashinfo)
{
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