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authorParav Pandit <parav@mellanox.com>2020-01-26 16:26:46 +0200
committerJason Gunthorpe <jgg@mellanox.com>2020-01-28 14:15:23 -0400
commitb4fb4cc5ba83b20dae13cef116c33648e81d2f44 (patch)
tree54131bb2aae71cd577f70fc94a7c2605be73f509 /drivers/infiniband
parentRDMA/umem: Fix ib_umem_find_best_pgsz() (diff)
downloadlinux-dev-b4fb4cc5ba83b20dae13cef116c33648e81d2f44.tar.xz
linux-dev-b4fb4cc5ba83b20dae13cef116c33648e81d2f44.zip
RDMA/cma: Fix unbalanced cm_id reference count during address resolve
Below commit missed the AF_IB and loopback code flow in rdma_resolve_addr(). This leads to an unbalanced cm_id refcount in cma_work_handler() which puts the refcount which was not incremented prior to queuing the work. A call trace is observed with such code flow: BUG: unable to handle kernel NULL pointer dereference at (null) [<ffffffff96b67e16>] __mutex_lock_slowpath+0x166/0x1d0 [<ffffffff96b6715f>] mutex_lock+0x1f/0x2f [<ffffffffc0beabb5>] cma_work_handler+0x25/0xa0 [<ffffffff964b9ebf>] process_one_work+0x17f/0x440 [<ffffffff964baf56>] worker_thread+0x126/0x3c0 Hence, hold the cm_id reference when scheduling the resolve work item. Fixes: 722c7b2bfead ("RDMA/{cma, core}: Avoid callback on rdma_addr_cancel()") Link: https://lore.kernel.org/r/20200126142652.104803-2-leon@kernel.org Signed-off-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Diffstat (limited to 'drivers/infiniband')
-rw-r--r--drivers/infiniband/core/cma.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index 55a9afacfedd..72f032160c4b 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -3148,6 +3148,7 @@ static int cma_resolve_loopback(struct rdma_id_private *id_priv)
rdma_addr_get_sgid(&id_priv->id.route.addr.dev_addr, &gid);
rdma_addr_set_dgid(&id_priv->id.route.addr.dev_addr, &gid);
+ atomic_inc(&id_priv->refcount);
cma_init_resolve_addr_work(work, id_priv);
queue_work(cma_wq, &work->work);
return 0;
@@ -3174,6 +3175,7 @@ static int cma_resolve_ib_addr(struct rdma_id_private *id_priv)
rdma_addr_set_dgid(&id_priv->id.route.addr.dev_addr, (union ib_gid *)
&(((struct sockaddr_ib *) &id_priv->id.route.addr.dst_addr)->sib_addr));
+ atomic_inc(&id_priv->refcount);
cma_init_resolve_addr_work(work, id_priv);
queue_work(cma_wq, &work->work);
return 0;