[PATCH] Ceph: Fix use-after-free bug in ceph_messenger_destroy()

From: Jesper Juhl
Date: Sat Dec 25 2010 - 13:21:43 EST


Hi,

In net/ceph/messenger.c::ceph_messenger_destroy() the pointer 'msgr' is
freed by kfree() and subsequently used in a call to dout() - use after
free bug.
Easily fixed by simply moving the kfree() call after the dout() call.

Signed-off-by: Jesper Juhl <jj@xxxxxxxxxxxxx>
---
messenger.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index b6ff4a1..26514a7 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -2131,8 +2131,8 @@ void ceph_messenger_destroy(struct ceph_messenger *msgr)
dout("destroy %p\n", msgr);
kunmap(msgr->zero_page);
__free_page(msgr->zero_page);
- kfree(msgr);
dout("destroyed messenger %p\n", msgr);
+ kfree(msgr);
}
EXPORT_SYMBOL(ceph_messenger_destroy);


--
Jesper Juhl <jj@xxxxxxxxxxxxx> http://www.chaosbits.net/
Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html
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