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Parav Pandit authored
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: 722c7b2b ("RDMA/{cma, core}: Avoid callback on rdma_addr_cancel()") Link: https://lore.kernel.org/r/20200126142652.104803-2-leon@kernel.orgSigned-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>
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