Revert "net: Add a second bind table hashed by port and address"

This reverts:

commit d5a42de8bdbe ("net: Add a second bind table hashed by port and address")
commit 538aaf9b2383 ("selftests: Add test for timing a bind request to a port with a populated bhash entry")
Link: https://lore.kernel.org/netdev/20220520001834.2247810-1-kuba@kernel.org/

There are a few things that need to be fixed here:
* Updating bhash2 in cases where the socket's rcv saddr changes
* Adding bhash2 hashbucket locks

Links to syzbot reports:
https://lore.kernel.org/netdev/00000000000022208805e0df247a@google.com/
https://lore.kernel.org/netdev/0000000000003f33bc05dfaf44fe@google.com/

Fixes: d5a42de8bdbe ("net: Add a second bind table hashed by port and address")
Reported-by: syzbot+015d756bbd1f8b5c8f09@syzkaller.appspotmail.com
Reported-by: syzbot+98fd2d1422063b0f8c44@syzkaller.appspotmail.com
Reported-by: syzbot+0a847a982613c6438fba@syzkaller.appspotmail.com
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Link: https://lore.kernel.org/r/20220615193213.2419568-1-joannelkoong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 5 insertions, 28 deletions

diff --git a/net/dccp/proto.c b/net/dccp/proto.c
index 2e78458900f2..eb8e128e43e8 100644
--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -1120,12 +1120,6 @@ static int __init dccp_init(void)
 				  SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
 	if (!dccp_hashinfo.bind_bucket_cachep)
 		goto out_free_hashinfo2;
-	dccp_hashinfo.bind2_bucket_cachep =
-		kmem_cache_create("dccp_bind2_bucket",
-				  sizeof(struct inet_bind2_bucket), 0,
-				  SLAB_HWCACHE_ALIGN | SLAB_ACCOUNT, NULL);
-	if (!dccp_hashinfo.bind2_bucket_cachep)
-		goto out_free_bind_bucket_cachep;
 
 	/*
 	 * Size and allocate the main established and bind bucket
@@ -1156,7 +1150,7 @@ static int __init dccp_init(void)
 
 	if (!dccp_hashinfo.ehash) {
 		DCCP_CRIT("Failed to allocate DCCP established hash table");
-		goto out_free_bind2_bucket_cachep;
+		goto out_free_bind_bucket_cachep;
 	}
 
 	for (i = 0; i <= dccp_hashinfo.ehash_mask; i++)
@@ -1182,23 +1176,14 @@ static int __init dccp_init(void)
 		goto out_free_dccp_locks;
 	}
 
-	dccp_hashinfo.bhash2 = (struct inet_bind2_hashbucket *)
-		__get_free_pages(GFP_ATOMIC | __GFP_NOWARN, bhash_order);
-
-	if (!dccp_hashinfo.bhash2) {
-		DCCP_CRIT("Failed to allocate DCCP bind2 hash table");
-		goto out_free_dccp_bhash;
-	}
-
 	for (i = 0; i < dccp_hashinfo.bhash_size; i++) {
 		spin_lock_init(&dccp_hashinfo.bhash[i].lock);
 		INIT_HLIST_HEAD(&dccp_hashinfo.bhash[i].chain);
-		INIT_HLIST_HEAD(&dccp_hashinfo.bhash2[i].chain);
 	}
 
 	rc = dccp_mib_init();
 	if (rc)
-		goto out_free_dccp_bhash2;
+		goto out_free_dccp_bhash;
 
 	rc = dccp_ackvec_init();
 	if (rc)
@@ -1222,38 +1207,30 @@ out_ackvec_exit:
 	dccp_ackvec_exit();
 out_free_dccp_mib:
 	dccp_mib_exit();
-out_free_dccp_bhash2:
-	free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order);
 out_free_dccp_bhash:
 	free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
 out_free_dccp_locks:
 	inet_ehash_locks_free(&dccp_hashinfo);
 out_free_dccp_ehash:
 	free_pages((unsigned long)dccp_hashinfo.ehash, ehash_order);
-out_free_bind2_bucket_cachep:
-	kmem_cache_destroy(dccp_hashinfo.bind2_bucket_cachep);
 out_free_bind_bucket_cachep:
 	kmem_cache_destroy(dccp_hashinfo.bind_bucket_cachep);
 out_free_hashinfo2:
 	inet_hashinfo2_free_mod(&dccp_hashinfo);
 out_fail:
 	dccp_hashinfo.bhash = NULL;
-	dccp_hashinfo.bhash2 = NULL;
 	dccp_hashinfo.ehash = NULL;
 	dccp_hashinfo.bind_bucket_cachep = NULL;
-	dccp_hashinfo.bind2_bucket_cachep = NULL;
 	return rc;
 }
 
 static void __exit dccp_fini(void)
 {
-	int bhash_order = get_order(dccp_hashinfo.bhash_size *
-				    sizeof(struct inet_bind_hashbucket));
-
 	ccid_cleanup_builtins();
 	dccp_mib_exit();
-	free_pages((unsigned long)dccp_hashinfo.bhash, bhash_order);
-	free_pages((unsigned long)dccp_hashinfo.bhash2, bhash_order);
+	free_pages((unsigned long)dccp_hashinfo.bhash,
+		   get_order(dccp_hashinfo.bhash_size *
+			     sizeof(struct inet_bind_hashbucket)));
 	free_pages((unsigned long)dccp_hashinfo.ehash,
 		   get_order((dccp_hashinfo.ehash_mask + 1) *
 			     sizeof(struct inet_ehash_bucket)));