Re: [PATCH] nvme-rdma: fix double free in nvme_rdma_free_queue

From: Christoph Hellwig
Date: Mon May 07 2018 - 08:24:30 EST


On Fri, May 04, 2018 at 04:02:18PM +0800, Jianchao Wang wrote:
> BUG: KASAN: double-free or invalid-free in nvme_rdma_free_queue+0xf6/0x110 [nvme_rdma]
> Workqueue: nvme-reset-wq nvme_rdma_reset_ctrl_work [nvme_rdma]
> Call Trace:
> dump_stack+0x91/0xeb
> print_address_description+0x6b/0x290
> kasan_report_invalid_free+0x55/0x80
> __kasan_slab_free+0x176/0x190
> kfree+0xeb/0x310
> nvme_rdma_free_queue+0xf6/0x110 [nvme_rdma]
> nvme_rdma_configure_admin_queue+0x1a3/0x4d0 [nvme_rdma]
> nvme_rdma_reset_ctrl_work+0x4e/0xd0 [nvme_rdma]
> process_one_work+0x3ca/0xaa0
> worker_thread+0x4e2/0x6c0
> kthread+0x18d/0x1e0
> ret_from_fork+0x24/0x30
>
> The double free is on ctrl->async_event_sqe.
> If nvme_rdma_start_queue in nvme_rdma_configure_admin_queue fails,
> nvme_rdma_free_queue will be invoked. However, at the moment, the
> ctrl->async_event_sqe has not been allocated and it has been freed
> in
> nvme_rdma_reset_ctrl_work
> -> nvme_rdma_shutdown_ctrl
> ->nvme_rdma_destroy_admin_queue
> -> nvme_rdma_free_queue
>
> Signed-off-by: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx>

Can you handle this in the caller instead, maybe including a comment?