Commit eedbbb0d authored Dec 16, 2018 by Peter Oskolkov Committed by David S. Miller Dec 17, 2018

net: dccp: initialize (addr,port) listening hashtable



Commit d9fbc7f6 "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: d9fbc7f6 "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>

parent 6a95147c

net/dccp/proto.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -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,

net/ipv4/inet_hashtables.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -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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