net: print proper warning on dst underflow

Proper warnings with stack traces make it much easier to figure out what's doing the double free and create more meaningful bug reports from users. Signed-off-by: Jason A. Donenfeld <[email protected]> Signed-off-by: David S. Miller <[email protected]>
vieko · Sep 26, 2019 · adecda5 · adecda5
1 parent 3e8b9bf
commit adecda5
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/net/core/dst.c b/net/core/dst.c
@@ -172,7 +172,7 @@ void dst_release(struct dst_entry *dst)
 		int newrefcnt;
 
 		newrefcnt = atomic_dec_return(&dst->__refcnt);
-		if (unlikely(newrefcnt < 0))
+		if (WARN_ONCE(newrefcnt < 0, "dst_release underflow"))
 			net_warn_ratelimited("%s: dst:%p refcnt:%d\n",
 					     __func__, dst, newrefcnt);
 		if (!newrefcnt)
@@ -187,7 +187,7 @@ void dst_release_immediate(struct dst_entry *dst)
 		int newrefcnt;
 
 		newrefcnt = atomic_dec_return(&dst->__refcnt);
-		if (unlikely(newrefcnt < 0))
+		if (WARN_ONCE(newrefcnt < 0, "dst_release_immediate underflow"))
 			net_warn_ratelimited("%s: dst:%p refcnt:%d\n",
 					     __func__, dst, newrefcnt);
 		if (!newrefcnt)