Re: [PATCH for-rc] RDMA/srpt: Fix UAF when srpt_add_one() failed

Zhu Yanjun
2024-08-01T21:55:37Z

在 2024/8/1 15:44, Junxian Huang 写道:
> Currently cancel_work_sync() is not called when srpt_refresh_port()
> failed in srpt_add_one(). There is a probability that sdev has been
> freed while the previously initiated sport->work is still running,
> leading to a UAF as the log below:
>
> [ T880] ib_srpt MAD registration failed for hns_1-1.
> [ T880] ib_srpt srpt_add_one(hns_1) failed.
> [ T376] Unable to handle kernel paging request at virtual address 0000000000010008
> ...
> [ T376] Workqueue: events srpt_refresh_port_work [ib_srpt]
> ...
> [ T376] Call trace:
> [ T376] srpt_refresh_port+0x94/0x264 [ib_srpt]
> [ T376] srpt_refresh_port_work+0x1c/0x2c [ib_srpt]
> [ T376] process_one_work+0x1d8/0x4cc
> [ T376] worker_thread+0x158/0x410
> [ T376] kthread+0x108/0x13c
> [ T376] ret_from_fork+0x10/0x18
>
> Add cancel_work_sync() to the exception branch to fix this UAF.

Can you share the method to reproduce this problem?
I am interested in this problem.

Thanks,
Zhu Yanjun

>
> Fixes: a42d985bd5b2 ("ib_srpt: Initial SRP Target merge for v3.3-rc1")
> Signed-off-by: Junxian Huang <huangjunxian6@hisilicon.com>
> ---
> drivers/infiniband/ulp/srpt/ib_srpt.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/infiniband/ulp/srpt/ib_srpt.c b/drivers/infiniband/ulp/srpt/ib_srpt.c
> index 9632afbd727b..244e5c115bf7 100644
> --- a/drivers/infiniband/ulp/srpt/ib_srpt.c
> +++ b/drivers/infiniband/ulp/srpt/ib_srpt.c
> @@ -3148,8 +3148,8 @@ static int srpt_add_one(struct ib_device *device)
> {
> struct srpt_device *sdev;
> struct srpt_port *sport;
> + u32 i, j;
> int ret;
> - u32 i;
>
> pr_debug("device = %p\n", device);
>
> @@ -3226,7 +3226,6 @@ static int srpt_add_one(struct ib_device *device)
> if (ret) {
> pr_err("MAD registration failed for %s-%d.\n",
> dev_name(&sdev->device->dev), i);
> - i--;
> goto err_port;
> }
> }
> @@ -3241,6 +3240,8 @@ static int srpt_add_one(struct ib_device *device)
> return 0;
>
> err_port:
> + for (j = i, i--; j > 0; j--)
> + cancel_work_sync(&sdev->port[j - 1].work);
> srpt_unregister_mad_agent(sdev, i);
> err_cm:
> if (sdev->cm_id)