Sagi Grimberg b2ec6c4a46 nvmet-rdma: fix possible bad dereference when freeing rsps
[ Upstream commit 73964c1d07c054376f1b32a62548571795159148 ]

It is possible that the host connected and saw a cm established
event and started sending nvme capsules on the qp, however the
ctrl did not yet see an established event. This is why the
rsp_wait_list exists (for async handling of these cmds, we move
them to a pending list).

Furthermore, it is possible that the ctrl cm times out, resulting
in a connect-error cm event. in this case we hit a bad deref [1]
because in nvmet_rdma_free_rsps we assume that all the responses
are in the free list.

We are freeing the cmds array anyways, so don't even bother to
remove the rsp from the free_list. It is also guaranteed that we
are not racing anything when we are releasing the queue so no
other context accessing this array should be running.

[1]:
--
Workqueue: nvmet-free-wq nvmet_rdma_free_queue_work [nvmet_rdma]
[...]
pc : nvmet_rdma_free_rsps+0x78/0xb8 [nvmet_rdma]
lr : nvmet_rdma_free_queue_work+0x88/0x120 [nvmet_rdma]
 Call trace:
 nvmet_rdma_free_rsps+0x78/0xb8 [nvmet_rdma]
 nvmet_rdma_free_queue_work+0x88/0x120 [nvmet_rdma]
 process_one_work+0x1ec/0x4a0
 worker_thread+0x48/0x490
 kthread+0x158/0x160
 ret_from_fork+0x10/0x18
--

Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-08-29 17:30:40 +02:00
2024-08-29 17:30:28 +02:00
2024-08-29 17:30:28 +02:00
2022-09-28 09:02:20 +02:00
2022-09-28 09:02:20 +02:00
2024-08-19 06:00:07 +02:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
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