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From: Dan Carpenter <dan.carpenter@oracle.com>
To: linux-sparse@vger.kernel.org
Subject: [PATCH] ptrlist: reading deleted items in NEXT_PTR_LIST()
Date: Thu, 23 Jul 2015 11:24:14 +0300	[thread overview]
Message-ID: <20150723082414.GA30778@mwanda> (raw)

If you call DELETE_CURRENT_PTR(), then you can sometimes end up with a
__list->nr that is zero.  The FOR_EACH_PTR() macro can handle this but
the NEXT_PTR_LIST() macro returns ptr = 0xf0f0f0f0 which leads to a
segfault.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
 ptrlist.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ptrlist.h b/ptrlist.h
index 58d3bda..61e159f 100644
--- a/ptrlist.h
+++ b/ptrlist.h
@@ -97,6 +97,8 @@ static inline void *last_ptr_list(struct ptr_list *list)
 			} else {							\
 				__list = __list->next;					\
 				ptr = NULL;						\
+				while (__list->nr == 0 && __list != __head)		\
+					__list = __list->next;				\
 				if (__list != __head) {					\
 					__nr = 0;					\
 					ptr = PTR_ENTRY(__list,0);			\
-- 
2.1.4


                 reply	other threads:[~2015-07-23  8:24 UTC|newest]

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