جزئیات آسیب‌پذیری

In the Linux kernel, the following vulnerability has been resolved: wifi: cfg80211: use wiphy work for socket owner autodisconnect nl80211_netlink_notify() walks the cfg80211 wireless device list when a NETLINK_GENERIC socket is released. If the socket owns a connection, the notifier queues the embedded wdev->disconnect_wk work item. That work is a plain work_struct today. NETDEV_GOING_DOWN cancels it, but a NETLINK_URELEASE notifier that already observed conn_owner_nlportid can queue it after that cancel returns. _cfg80211_unregister_wdev() then removes the wdev from the list and waits for RCU readers, but synchronize_net() does not drain work queued by such a reader. Make the autodisconnect work a wiphy_work instead. The callback already needs the wiphy mutex, and wiphy_work runs under that mutex. This lets teardown cancel pending autodisconnect work while holding the mutex, without a cancel_work_sync() vs. worker locking concern. Also cancel the wiphy work after list_del_rcu() and synchronize_net(). Any NETLINK_URELEASE notifier that had already reached the wdev list has then either queued the work and it is removed, or can no longer find the wdev.

• https://git.kernel.org/stable/c/23517673b1eecaec95e61dde285220d5a980cf3f
• https://git.kernel.org/stable/c/c55590e4c69e0fd194df6d20bc35381c201d99e1
• https://git.kernel.org/stable/c/4087a9ba4ece70297a4174afaa41c0b700302b65
• https://git.kernel.org/stable/c/c2ddd180bbee766cf7359473d623423ea9485d93
• https://git.kernel.org/stable/c/6d6123fef5a4af175cc6b6b12a03dd0f3c240b79
• https://git.kernel.org/stable/c/0c2ed186bbe14304415476d6707b747dddcd8583