2.6 KiB
CVE-2024-56599
Description
In the Linux kernel, the following vulnerability has been resolved:wifi: ath10k: avoid NULL pointer error during sdio removeWhen running 'rmmod ath10k', ath10k_sdio_remove() will free sdioworkqueue by destroy_workqueue(). But if CONFIG_INIT_ON_FREE_DEFAULT_ONis set to yes, kernel panic will happen:Call trace: destroy_workqueue+0x1c/0x258 ath10k_sdio_remove+0x84/0x94 sdio_bus_remove+0x50/0x16c device_release_driver_internal+0x188/0x25c device_driver_detach+0x20/0x2cThis is because during 'rmmod ath10k', ath10k_sdio_remove() will callath10k_core_destroy() before destroy_workqueue(). wiphy_dev_release()will finally be called in ath10k_core_destroy(). This function will freestruct cfg80211_registered_device *rdev and all its members, includingwiphy, dev and the pointer of sdio workqueue. Then the pointer of sdioworkqueue will be set to NULL due to CONFIG_INIT_ON_FREE_DEFAULT_ON.After device release, destroy_workqueue() will use NULL pointer then thekernel panic happen.Call trace:ath10k_sdio_remove ->ath10k_core_unregister …… ->ath10k_core_stop ->ath10k_hif_stop ->ath10k_sdio_irq_disable ->ath10k_hif_power_down ->del_timer_sync(&ar_sdio->sleep_timer) ->ath10k_core_destroy ->ath10k_mac_destroy ->ieee80211_free_hw ->wiphy_free …… ->wiphy_dev_release ->destroy_workqueueNeed to call destroy_workqueue() before ath10k_core_destroy(), freethe work queue buffer first and then free pointer of work queue byath10k_core_destroy(). This order matches the error path order inath10k_sdio_probe().No work will be queued on sdio workqueue between it is destroyed andath10k_core_destroy() is called. Based on the call_stack above, thereason is:Only ath10k_sdio_sleep_timer_handler(), ath10k_sdio_hif_tx_sg() andath10k_sdio_irq_disable() will queue work on sdio workqueue.Sleep timer will be deleted before ath10k_core_destroy() inath10k_hif_power_down().ath10k_sdio_irq_disable() only be called in ath10k_hif_stop().ath10k_core_unregister() will call ath10k_hif_power_down() to stop hifbus, so ath10k_sdio_hif_tx_sg() won't be called anymore.Tested-on: QCA6174 hw3.2 SDIO WLAN.RMH.4.4.1-00189
POC
Reference
No PoCs from references.