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Date: Tue, 27 Jun 2017 20:58:47 +0300
From: Alexander Monakov <amonakov@...ras.ru>
To: musl@...ts.openwall.com
Subject: [PATCH] fix undefined behavior in free

---
 src/malloc/malloc.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/malloc/malloc.c b/src/malloc/malloc.c
index 720fa696..ef4c7368 100644
--- a/src/malloc/malloc.c
+++ b/src/malloc/malloc.c
@@ -463,14 +463,15 @@ copy_realloc:
 
 void free(void *p)
 {
-	struct chunk *self = MEM_TO_CHUNK(p);
-	struct chunk *next;
+	struct chunk *self, *next;
 	size_t final_size, new_size, size;
 	int reclaim=0;
 	int i;
 
 	if (!p) return;
 
+	self = MEM_TO_CHUNK(p);
+
 	if (IS_MMAPPED(self)) {
 		size_t extra = self->psize;
 		char *base = (char *)self - extra;
-- 
2.11.0

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