1 files changed, 12 insertions, 1 deletions
diff --git a/malloc/malloc.c b/malloc/malloc.c
index c3855290f7..e4b693c342 100644
--- a/malloc/malloc.c
+++ b/malloc/malloc.c
@@ -2741,8 +2741,19 @@ static void do_check_malloc_state(mstate av)
   for (i = 0; i < NFASTBINS; ++i) {
     p = av->fastbins[i];
 
+    /* The following test can only be performed for the main arena.
+       While mallopt calls malloc_consolidate to get rid of all fast
+       bins (especially those larger than the new maximum) this does
+       only happen for the main arena.  Trying to do this for any
+       other arena would mean those arenas have to be locked and
+       malloc_consolidate be called for them.  This is excessive.  And
+       even if this is acceptable to somebody it still cannot solve
+       the problem completely since if the arena is locked a
+       concurrent malloc call might create a new arena which then
+       could use the newly invalid fast bins.  */
+
     /* all bins past max_fast are empty */
-    if (i > max_fast_bin)
+    if (av == &main_arena && i > max_fast_bin)
       assert(p == 0);
 
     while (p != 0) {