linux/net/9p
Zheng Wang ea4f100940
9p/xen : Fix use after free bug in xen_9pfs_front_remove due to race condition
In xen_9pfs_front_probe, it calls xen_9pfs_front_alloc_dataring
to init priv->rings and bound &ring->work with p9_xen_response.

When it calls xen_9pfs_front_event_handler to handle IRQ requests,
it will finally call schedule_work to start the work.

When we call xen_9pfs_front_remove to remove the driver, there
may be a sequence as follows:

Fix it by finishing the work before cleanup in xen_9pfs_front_free.

Note that, this bug is found by static analysis, which might be
false positive.

CPU0                  CPU1

                     |p9_xen_response
xen_9pfs_front_remove|
  xen_9pfs_front_free|
kfree(priv)          |
//free priv          |
                     |p9_tag_lookup
                     |//use priv->client

Fixes: 71ebd71921 ("xen/9pfs: connect to the backend")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: Eric Van Hensbergen <ericvh@kernel.org>
2023-04-02 01:00:31 +00:00
..
client.c net/9p: fix bug in client create for .L 2023-02-24 13:42:40 +00:00
error.c 9p: fix a bunch of checkpatch warnings 2021-11-04 21:04:25 +09:00
Kconfig 9p/trans_fd: split into dedicated module 2022-01-10 09:58:30 +09:00
Makefile 9p/trans_fd: split into dedicated module 2022-01-10 09:58:30 +09:00
mod.c net/p9: load default transports 2022-01-10 10:00:09 +09:00
protocol.c net/9p: add p9_msg_buf_size() 2022-10-05 07:05:41 +09:00
protocol.h net/9p: add p9_msg_buf_size() 2022-10-05 07:05:41 +09:00
trans_common.c 9p: fix file headers 2021-11-03 17:45:04 +09:00
trans_common.h 9p: fix a bunch of checkpatch warnings 2021-11-04 21:04:25 +09:00
trans_fd.c 9p-for-6.2-rc1 2022-12-23 11:39:18 -08:00
trans_rdma.c 9p/rdma: unmap receive dma buffer in rdma_request()/post_recv() 2023-02-24 13:42:28 +00:00
trans_virtio.c 9p/client: fix data race on req->status 2022-12-13 13:02:15 +09:00
trans_xen.c 9p/xen : Fix use after free bug in xen_9pfs_front_remove due to race condition 2023-04-02 01:00:31 +00:00