From af59306455587143615517ade1ffce2e8f4fda48 Mon Sep 17 00:00:00 2001 From: Ilya Dryomov Date: Fri, 20 Jun 2014 18:29:20 +0400 Subject: [PATCH] libceph: unregister only registered linger requests Linger requests that have not yet been registered should not be unregistered by __unregister_linger_request(). This messes up ref count and leads to use-after-free. Signed-off-by: Ilya Dryomov Reviewed-by: Alex Elder --- net/ceph/osd_client.c | 19 ++++++++++++++----- 1 file changed, 14 insertions(+), 5 deletions(-) diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c index a9b7ea7bfdc6..943dba916ab1 100644 --- a/net/ceph/osd_client.c +++ b/net/ceph/osd_client.c @@ -1248,7 +1248,9 @@ static void __cancel_request(struct ceph_osd_request *req) static void __register_linger_request(struct ceph_osd_client *osdc, struct ceph_osd_request *req) { - dout("__register_linger_request %p\n", req); + dout("%s %p tid %llu\n", __func__, req, req->r_tid); + WARN_ON(!req->r_linger); + ceph_osdc_get_request(req); list_add_tail(&req->r_linger_item, &osdc->req_linger); if (req->r_osd) @@ -1259,8 +1261,17 @@ static void __register_linger_request(struct ceph_osd_client *osdc, static void __unregister_linger_request(struct ceph_osd_client *osdc, struct ceph_osd_request *req) { - dout("__unregister_linger_request %p\n", req); + WARN_ON(!req->r_linger); + + if (list_empty(&req->r_linger_item)) { + dout("%s %p tid %llu not registered\n", __func__, req, + req->r_tid); + return; + } + + dout("%s %p tid %llu\n", __func__, req, req->r_tid); list_del_init(&req->r_linger_item); + if (req->r_osd) { list_del_init(&req->r_linger_osd_item); maybe_move_osd_to_lru(osdc, req->r_osd); @@ -1274,10 +1285,8 @@ void ceph_osdc_unregister_linger_request(struct ceph_osd_client *osdc, struct ceph_osd_request *req) { mutex_lock(&osdc->request_mutex); - if (req->r_linger) { - req->r_linger = 0; + if (req->r_linger) __unregister_linger_request(osdc, req); - } mutex_unlock(&osdc->request_mutex); } EXPORT_SYMBOL(ceph_osdc_unregister_linger_request);