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| author |   Shay Drory <shayd@mellanox.com> | 2020-06-21 13:47:35 +0300 |
|---|---|---|
| committer |   Jason Gunthorpe <jgg@nvidia.com> | 2020-06-22 14:57:44 -0300 |
| commit | 116a1b9f1cb769b83e5adff323f977a62b1dcb2e (patch) | |
| tree | 240f19fc8e9dc30e5ba24d508ba8adfa79c1cdf3 /drivers/infiniband/core/mad.c | |
| parent | RDMA/mlx5: Protect from kernel crash if XRC_TGT doesn't have udata (diff) | |
| download | linux-dev-116a1b9f1cb769b83e5adff323f977a62b1dcb2e.tar.xz linux-dev-116a1b9f1cb769b83e5adff323f977a62b1dcb2e.zip | |
IB/mad: Fix use after free when destroying MAD agent
Currently, when RMPP MADs are processed while the MAD agent is destroyed,
it could result in use after free of rmpp_recv, as decribed below:
cpu-0 cpu-1
----- -----
ib_mad_recv_done()
ib_mad_complete_recv()
ib_process_rmpp_recv_wc()
unregister_mad_agent()
ib_cancel_rmpp_recvs()
cancel_delayed_work()
process_rmpp_data()
start_rmpp()
queue_delayed_work(rmpp_recv->cleanup_work)
destroy_rmpp_recv()
free_rmpp_recv()
cleanup_work()[1]
spin_lock_irqsave(&rmpp_recv->agent->lock) <-- use after free
[1] cleanup_work() == recv_cleanup_handler
Fix it by waiting for the MAD agent reference count becoming zero before
calling to ib_cancel_rmpp_recvs().
Fixes: 9a41e38a467c ("IB/mad: Use IDR for agent IDs")
Link: https://lore.kernel.org/r/20200621104738.54850-2-leon@kernel.org
Signed-off-by: Shay Drory <shayd@mellanox.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/infiniband/core/mad.c')
| -rw-r--r-- | drivers/infiniband/core/mad.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c index 5e080191a725..a09f8e3c7f3f 100644 --- a/drivers/infiniband/core/mad.c +++ b/drivers/infiniband/core/mad.c @@ -509,10 +509,10 @@ static void unregister_mad_agent(struct ib_mad_agent_private *mad_agent_priv) xa_erase(&ib_mad_clients, mad_agent_priv->agent.hi_tid); flush_workqueue(port_priv->wq); - ib_cancel_rmpp_recvs(mad_agent_priv); deref_mad_agent(mad_agent_priv); wait_for_completion(&mad_agent_priv->comp); + ib_cancel_rmpp_recvs(mad_agent_priv); ib_mad_agent_security_cleanup(&mad_agent_priv->agent); |