Minsuk Kang <linuxlovemin@xxxxxxxxxxxx> writes: > This patch fixes a use-after-free in ath9k that occurs in > ath9k_hif_usb_disconnect() when ath9k_destroy_wmi() is trying to access > 'drv_priv' that has already been freed by ieee80211_free_hw(), called by > ath9k_htc_hw_deinit(). The patch moves ath9k_destroy_wmi() before > ieee80211_free_hw(). Note that urbs from the driver should be killed > before freeing 'wmi' with ath9k_destroy_wmi() as their callbacks will > access 'wmi'. > > Found by a modified version of syzkaller. > > ================================================================== > BUG: KASAN: use-after-free in ath9k_destroy_wmi+0x38/0x40 > Read of size 8 at addr ffff8881069132a0 by task kworker/0:1/7 > > CPU: 0 PID: 7 Comm: kworker/0:1 Tainted: G O 5.14.0+ #131 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 > Workqueue: usb_hub_wq hub_event > Call Trace: > dump_stack_lvl+0x8e/0xd1 > print_address_description.constprop.0.cold+0x93/0x334 > ? ath9k_destroy_wmi+0x38/0x40 > ? ath9k_destroy_wmi+0x38/0x40 > kasan_report.cold+0x83/0xdf > ? ath9k_destroy_wmi+0x38/0x40 > ath9k_destroy_wmi+0x38/0x40 > ath9k_hif_usb_disconnect+0x329/0x3f0 > ? ath9k_hif_usb_suspend+0x120/0x120 > ? usb_disable_interface+0xfc/0x180 > usb_unbind_interface+0x19b/0x7e0 > ? usb_autoresume_device+0x50/0x50 > device_release_driver_internal+0x44d/0x520 > bus_remove_device+0x2e5/0x5a0 > device_del+0x5b2/0xe30 > ? __device_link_del+0x370/0x370 > ? usb_remove_ep_devs+0x43/0x80 > ? remove_intf_ep_devs+0x112/0x1a0 > usb_disable_device+0x1e3/0x5a0 > usb_disconnect+0x267/0x870 > hub_event+0x168d/0x3950 > ? rcu_read_lock_sched_held+0xa1/0xd0 > ? hub_port_debounce+0x2e0/0x2e0 > ? check_irq_usage+0x860/0xf20 > ? drain_workqueue+0x281/0x360 > ? lock_release+0x640/0x640 > ? rcu_read_lock_sched_held+0xa1/0xd0 > ? rcu_read_lock_bh_held+0xb0/0xb0 > ? lockdep_hardirqs_on_prepare+0x273/0x3e0 > process_one_work+0x92b/0x1460 > ? pwq_dec_nr_in_flight+0x330/0x330 > ? rwlock_bug.part.0+0x90/0x90 > worker_thread+0x95/0xe00 > ? __kthread_parkme+0x115/0x1e0 > ? process_one_work+0x1460/0x1460 > kthread+0x3a1/0x480 > ? set_kthread_struct+0x120/0x120 > ret_from_fork+0x1f/0x30 > > The buggy address belongs to the page: > page:ffffea00041a44c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x106913 > flags: 0x200000000000000(node=0|zone=2) > raw: 0200000000000000 0000000000000000 dead000000000122 0000000000000000 > raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > page_owner tracks the page as freed > page last allocated via order 3, migratetype Unmovable, gfp_mask 0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), pid 7, ts 38347963444, free_ts 41399957635 > prep_new_page+0x1aa/0x240 > get_page_from_freelist+0x159a/0x27c0 > __alloc_pages+0x2da/0x6a0 > alloc_pages+0xec/0x1e0 > kmalloc_order+0x39/0xf0 > kmalloc_order_trace+0x19/0x120 > __kmalloc+0x308/0x390 > wiphy_new_nm+0x6f5/0x1dd0 > ieee80211_alloc_hw_nm+0x36d/0x2230 > ath9k_htc_probe_device+0x9d/0x1e10 > ath9k_htc_hw_init+0x34/0x50 > ath9k_hif_usb_firmware_cb+0x25f/0x4e0 > request_firmware_work_func+0x131/0x240 > process_one_work+0x92b/0x1460 > worker_thread+0x95/0xe00 > kthread+0x3a1/0x480 > page last free stack trace: > free_pcp_prepare+0x3d3/0x7f0 > free_unref_page+0x1e/0x3d0 > device_release+0xa4/0x240 > kobject_put+0x186/0x4c0 > put_device+0x20/0x30 > ath9k_htc_disconnect_device+0x1cf/0x2c0 > ath9k_htc_hw_deinit+0x26/0x30 > ath9k_hif_usb_disconnect+0x2d9/0x3f0 > usb_unbind_interface+0x19b/0x7e0 > device_release_driver_internal+0x44d/0x520 > bus_remove_device+0x2e5/0x5a0 > device_del+0x5b2/0xe30 > usb_disable_device+0x1e3/0x5a0 > usb_disconnect+0x267/0x870 > hub_event+0x168d/0x3950 > process_one_work+0x92b/0x1460 > > Memory state around the buggy address: > ffff888106913180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ffff888106913200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >>ffff888106913280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ^ > ffff888106913300: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ffff888106913380: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff > ================================================================== > > Reported-by: Dokyung Song <dokyungs@xxxxxxxxxxxx> > Reported-by: Jisoo Jang <jisoo.jang@xxxxxxxxxxxx> > Reported-by: Minsuk Kang <linuxlovemin@xxxxxxxxxxxx> > Signed-off-by: Minsuk Kang <linuxlovemin@xxxxxxxxxxxx> Acked-by: Toke Høiland-Jørgensen <toke@xxxxxxx>
