39 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
			
		
		
	
	
			39 lines
		
	
	
		
			1.4 KiB
		
	
	
	
		
			Diff
		
	
	
	
	
	
| From 4757898440d52b0adbf7ec7ee7f0f89b61aac0fb Mon Sep 17 00:00:00 2001
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| From: Mark Andrews <marka@isc.org>
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| Date: Fri, 18 Dec 2020 13:31:07 +1100
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| Subject: [PATCH] Inactive incorrectly incremented
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| 
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| It is possible to have two threads destroying an rbtdb at the same
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| time when detachnode() executes and removes the last reference to
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| a node between exiting being set to true for the node and testing
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| if the references are zero in maybe_free_rbtdb().  Move NODE_UNLOCK()
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| to after checking if references is zero to prevent detachnode()
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| changing the reference count too early.
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| 
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| (cherry picked from commit 859d2fdad6d1c6ff20083a4c463a929cbeb26438)
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| (cherry picked from commit 25150c15e7cfa73289f04470e2e699ebb7c28fef)
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| ---
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|  lib/dns/rbtdb.c | 2 +-
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|  1 file changed, 1 insertion(+), 1 deletion(-)
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| 
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| diff --git a/lib/dns/rbtdb.c b/lib/dns/rbtdb.c
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| index 8ea4d47..77ef7a4 100644
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| --- a/lib/dns/rbtdb.c
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| +++ b/lib/dns/rbtdb.c
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| @@ -1460,11 +1460,11 @@ maybe_free_rbtdb(dns_rbtdb_t *rbtdb) {
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|  	for (i = 0; i < rbtdb->node_lock_count; i++) {
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|  		NODE_LOCK(&rbtdb->node_locks[i].lock, isc_rwlocktype_write);
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|  		rbtdb->node_locks[i].exiting = true;
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| -		NODE_UNLOCK(&rbtdb->node_locks[i].lock, isc_rwlocktype_write);
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|  		if (isc_refcount_current(&rbtdb->node_locks[i].references)
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|  		    == 0) {
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|  			inactive++;
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|  		}
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| +		NODE_UNLOCK(&rbtdb->node_locks[i].lock, isc_rwlocktype_write);
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|  	}
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|  
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|  	if (inactive != 0) {
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| -- 
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| 2.26.3
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| 
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