android_kernel_xiaomi_sm8450/net/9p
Zheng Wang 9266e939d7 9p/xen : Fix use after free bug in xen_9pfs_front_remove due to race condition
[ Upstream commit ea4f1009408efb4989a0f139b70fb338e7f687d0 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-20 12:10:25 +02:00
..
client.c net/9p: Initialize the iounit field during fid creation 2022-08-21 15:16:26 +02:00
error.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 188 2019-05-30 11:29:21 -07:00
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile 9p: Remove p9_idpool 2018-08-29 13:39:57 +09:00
mod.c net: Add MODULE_DESCRIPTION entries to network modules 2020-06-20 21:33:57 -07:00
protocol.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 188 2019-05-30 11:29:21 -07:00
protocol.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 188 2019-05-30 11:29:21 -07:00
trans_common.c net/9p: include trans_common.h to fix missing prototype warning. 2018-11-20 15:04:16 +09:00
trans_common.h net/9p: remove (now-)unused helpers 2015-04-11 22:28:29 -04:00
trans_fd.c 9p/fd: Use P9_HDRSZ for header size 2022-12-14 11:31:53 +01:00
trans_rdma.c 9p/rdma: unmap receive dma buffer in rdma_request()/post_recv() 2023-03-11 16:40:13 +01:00
trans_virtio.c 9p/trans_virtio: Remove sysfs file on probe failure 2021-09-26 14:08:57 +02:00
trans_xen.c 9p/xen : Fix use after free bug in xen_9pfs_front_remove due to race condition 2023-04-20 12:10:25 +02:00