From 94aa8ae13db2ecf2ec1b4e65a65d3fe92b468e0e Mon Sep 17 00:00:00 2001
From: Sage Weil <sage@newdream.net>
Date: Sun, 28 Mar 2010 21:22:50 -0700
Subject: [PATCH] ceph: fix use after free on mds __unregister_request
There was a use after free in __unregister_request that would trigger
whenever the request map held the last reference. This appears to have
triggered an oops during 'umount -f' when requests are being torn down.
Signed-off-by: Sage Weil <sage@newdream.net>
---
fs/ceph/mds_client.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 5268d404963c8..5c7920be6420e 100644
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -532,7 +532,6 @@ static void __unregister_request(struct ceph_mds_client *mdsc,
dout("__unregister_request %p tid %lld\n", req, req->r_tid);
rb_erase(&req->r_node, &mdsc->request_tree);
RB_CLEAR_NODE(&req->r_node);
- ceph_mdsc_put_request(req);
if (req->r_unsafe_dir) {
struct ceph_inode_info *ci = ceph_inode(req->r_unsafe_dir);
@@ -541,6 +540,8 @@ static void __unregister_request(struct ceph_mds_client *mdsc,
list_del_init(&req->r_unsafe_dir_item);
spin_unlock(&ci->i_unsafe_lock);
}
+
+ ceph_mdsc_put_request(req);
}
/*
--
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