[Xen-devel] [PATCH 5/8] mini-os: fix use-after-free in xs_daemon_close event iteration

[Matthew Daley <mattjd@xxxxxxxxx>]

We need to get the next pointer before the freeing of the event.

Coverity-ID: 1056173
Signed-off-by: Matthew Daley <mattjd@xxxxxxxxx>
---
 extras/mini-os/lib/xs.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/extras/mini-os/lib/xs.c b/extras/mini-os/lib/xs.c
index a2a1220..c603d17 100644
--- a/extras/mini-os/lib/xs.c
+++ b/extras/mini-os/lib/xs.c
@@ -29,9 +29,12 @@ struct xs_handle *xs_daemon_open()
 void xs_daemon_close(struct xs_handle *h)
 {
     int fd = _xs_fileno(h);
-    struct xenbus_event *event;
-    for (event = files[fd].xenbus.events; event; event = event->next)
+    struct xenbus_event *event, *next;
+    for (event = files[fd].xenbus.events; event; event = next)
+    {
+        next = event->next;
         free(event);
+    }
     files[fd].type = FTYPE_NONE;
 }
 
-- 
1.7.10.4


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