Messages in this thread Patch in this message | | | From | Xiyu Yang <> | Subject | [PATCH] ceph: Fix potential ceph_osd_request refcnt leak | Date | Mon, 20 Apr 2020 13:40:43 +0800 |
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ceph_writepages_start() invokes ceph_osdc_start_request(), which increases the refcount of the ceph_osd_request object "req" and then submit the request.
When ceph_writepages_start() returns or a new object is assigned to "req", the original local reference of "req" becomes invalid, so the refcount should be decreased to keep refcount balanced.
The reference counting issue happens in a normal path of ceph_writepages_start(). Before NULL assigned to "req", the function forgets to decrease its refcnt increased by ceph_osdc_start_request() and will cause a refcnt leak.
Fix this issue by calling ceph_osdc_put_request() before the original object pointed by "req" becomes invalid.
Fixes: 1d3576fd10f0 ("ceph: address space operations") Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> --- fs/ceph/addr.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c index 7ab616601141..b02c050a3418 100644 --- a/fs/ceph/addr.c +++ b/fs/ceph/addr.c @@ -1126,6 +1126,7 @@ static int ceph_writepages_start(struct address_space *mapping, req->r_mtime = inode->i_mtime; rc = ceph_osdc_start_request(&fsc->client->osdc, req, true); BUG_ON(rc); + ceph_osdc_put_request(req); req = NULL; wbc->nr_to_write -= i; -- 2.7.4
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