From: Zheng Wang <zyytlz.wz@163.com> maillist inclusion category: bugfix bugzilla: 188655, https://gitee.com/src-openeuler/kernel/issues/I6T36H CVE: CVE-2023-1859 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?... ---------------------------------------- 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: 71ebd71921e4 ("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: Lu Wei <luwei32@huawei.com> Reviewed-by: Yue Haibing <yuehaibing@huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com> --- net/9p/trans_xen.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/9p/trans_xen.c b/net/9p/trans_xen.c index 81002cba88b3..8e158f09cba8 100644 --- a/net/9p/trans_xen.c +++ b/net/9p/trans_xen.c @@ -290,6 +290,10 @@ static void xen_9pfs_front_free(struct xen_9pfs_front_priv *priv) write_unlock(&xen_9pfs_lock); for (i = 0; i < priv->num_rings; i++) { + struct xen_9pfs_dataring *ring = &priv->rings[i]; + + cancel_work_sync(&ring->work); + if (!priv->rings[i].intf) break; if (priv->rings[i].irq > 0) -- 2.25.1