There are UAF bugs caused by do_submit_urb(). One of the KASan reports
is shown below:
[ 36.403605] BUG: KASAN: use-after-free in worker_thread+0x4a2/0x890
[ 36.406105] Read of size 8 at addr ffff8880059600e8 by task kworker/0:2/49
[ 36.408316]
[ 36.408867] CPU: 0 PID: 49 Comm: kworker/0:2 Not tainted 6.2.0-rc3-15798-g5a41237ad1d4-dir8
[ 36.411696] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g15584
[ 36.416157] Workqueue: 0x0 (events)
[ 36.417654] Call Trace:
[ 36.418546] <TASK>
[ 36.419320] dump_stack_lvl+0x96/0xd0
[ 36.420522] print_address_description+0x75/0x350
[ 36.421992] print_report+0x11b/0x250
[ 36.423174] ? _raw_spin_lock_irqsave+0x87/0xd0
[ 36.424806] ? __virt_addr_valid+0xcf/0x170
[ 36.426069] ? worker_thread+0x4a2/0x890
[ 36.427355] kasan_report+0x131/0x160
[ 36.428556] ? worker_thread+0x4a2/0x890
[ 36.430053] worker_thread+0x4a2/0x890
[ 36.431297] ? worker_clr_flags+0x90/0x90
[ 36.432479] kthread+0x166/0x190
[ 36.433493] ? kthread_blkcg+0x50/0x50
[ 36.434669] ret_from_fork+0x22/0x30
[ 36.435923] </TASK>
[ 36.436684]
[ 36.437215] Allocated by task 24:
[ 36.438289] kasan_set_track+0x50/0x80
[ 36.439436] __kasan_kmalloc+0x89/0xa0
[ 36.440566] smsusb_probe+0x374/0xc90
[ 36.441920] usb_probe_interface+0x2d1/0x4c0
[ 36.443253] really_probe+0x1d5/0x580
[ 36.444539] __driver_probe_device+0xe3/0x130
[ 36.446085] driver_probe_device+0x49/0x220
[ 36.447423] __device_attach_driver+0x19e/0x1b0
[ 36.448931] bus_for_each_drv+0xcb/0x110
[ 36.450217] __device_attach+0x132/0x1f0
[ 36.451470] bus_probe_device+0x59/0xf0
[ 36.452563] device_add+0x4ec/0x7b0
[ 36.453830] usb_set_configuration+0xc63/0xe10
[ 36.455230] usb_generic_driver_probe+0x3b/0x80
[ 36.456166] printk: console [ttyGS0] disabled
[ 36.456569] usb_probe_device+0x90/0x110
[ 36.459523] really_probe+0x1d5/0x580
[ 36.461027] __driver_probe_device+0xe3/0x130
[ 36.462465] driver_probe_device+0x49/0x220
[ 36.463847] __device_attach_driver+0x19e/0x1b0
[ 36.465229] bus_for_each_drv+0xcb/0x110
[ 36.466466] __device_attach+0x132/0x1f0
[ 36.467799] bus_probe_device+0x59/0xf0
[ 36.469010] device_add+0x4ec/0x7b0
[ 36.470125] usb_new_device+0x863/0xa00
[ 36.471374] hub_event+0x18c7/0x2220
[ 36.472746] process_one_work+0x34c/0x5b0
[ 36.474041] worker_thread+0x4b7/0x890
[ 36.475216] kthread+0x166/0x190
[ 36.476267] ret_from_fork+0x22/0x30
[ 36.477447]
[ 36.478160] Freed by task 24:
[ 36.479239] kasan_set_track+0x50/0x80
[ 36.480512] kasan_save_free_info+0x2b/0x40
[ 36.481808] ____kasan_slab_free+0x122/0x1a0
[ 36.483173] __kmem_cache_free+0xc4/0x200
[ 36.484563] smsusb_term_device+0xcd/0xf0
[ 36.485896] smsusb_probe+0xc85/0xc90
[ 36.486976] usb_probe_interface+0x2d1/0x4c0
[ 36.488303] really_probe+0x1d5/0x580
[ 36.489498] __driver_probe_device+0xe3/0x130
[ 36.491140] driver_probe_device+0x49/0x220
[ 36.492475] __device_attach_driver+0x19e/0x1b0
[ 36.493988] bus_for_each_drv+0xcb/0x110
[ 36.495171] __device_attach+0x132/0x1f0
[ 36.496617] bus_probe_device+0x59/0xf0
[ 36.497875] device_add+0x4ec/0x7b0
[ 36.498972] usb_set_configuration+0xc63/0xe10
[ 36.500264] usb_generic_driver_probe+0x3b/0x80
[ 36.501740] usb_probe_device+0x90/0x110
[ 36.503084] really_probe+0x1d5/0x580
[ 36.504241] __driver_probe_device+0xe3/0x130
[ 36.505548] driver_probe_device+0x49/0x220
[ 36.506766] __device_attach_driver+0x19e/0x1b0
[ 36.508368] bus_for_each_drv+0xcb/0x110
[ 36.509646] __device_attach+0x132/0x1f0
[ 36.510911] bus_probe_device+0x59/0xf0
[ 36.512103] device_add+0x4ec/0x7b0
[ 36.513215] usb_new_device+0x863/0xa00
[ 36.514736] hub_event+0x18c7/0x2220
[ 36.516130] process_one_work+0x34c/0x5b0
[ 36.517396] worker_thread+0x4b7/0x890
[ 36.518591] kthread+0x166/0x190
[ 36.519599] ret_from_fork+0x22/0x30
[ 36.520851]
[ 36.521405] Last potentially related work creation:
[ 36.523143] kasan_save_stack+0x3f/0x60
[ 36.524275] kasan_record_aux_stack_noalloc+0x9d/0xb0
[ 36.525831] insert_work+0x25/0x130
[ 36.527039] __queue_work+0x4d4/0x620
[ 36.528236] queue_work_on+0x72/0xb0
[ 36.529344] __usb_hcd_giveback_urb+0x13f/0x1b0
[ 36.530819] dummy_timer+0x350/0x1a40
[ 36.532149] call_timer_fn+0x2c/0x190
[ 36.533567] expire_timers+0x69/0x1f0
[ 36.534736] __run_timers+0x289/0x2d0
[ 36.535841] run_timer_softirq+0x2d/0x60
[ 36.537110] __do_softirq+0x116/0x380
[ 36.538377]
[ 36.538950] Second to last potentially related work creation:
[ 36.540855] kasan_save_stack+0x3f/0x60
[ 36.542084] kasan_record_aux_stack_noalloc+0x9d/0xb0
[ 36.543592] insert_work+0x25/0x130
[ 36.544891] __queue_work+0x4d4/0x620
[ 36.546168] queue_work_on+0x72/0xb0
[ 36.547328] __usb_hcd_giveback_urb+0x13f/0x1b0
[ 36.548805] dummy_timer+0x350/0x1a40
[ 36.550116] call_timer_fn+0x2c/0x190
[ 36.551570] expire_timers+0x69/0x1f0
[ 36.552762] __run_timers+0x289/0x2d0
[ 36.553916] run_timer_softirq+0x2d/0x60
[ 36.555118] __do_softirq+0x116/0x380
[ 36.556239]
[ 36.556807] The buggy address belongs to the object at ffff888005960000
[ 36.556807] which belongs to the cache kmalloc-4k of size 4096
[ 36.560652] The buggy address is located 232 bytes inside of
[ 36.560652] 4096-byte region [ffff888005960000, ffff888005961000)
[ 36.564791]
[ 36.565355] The buggy address belongs to the physical page:
[ 36.567212] page:000000004f0a0731 refcount:1 mapcount:0 mapping:0000000000000000 index:0x00
[ 36.570534] head:000000004f0a0731 order:3 compound_mapcount:0 subpages_mapcount:0 compound0
[ 36.573717] flags: 0x100000000010200(slab|head|node=0|zone=1)
[ 36.575481] raw: 0100000000010200 ffff888001042140 dead000000000122 0000000000000000
[ 36.577842] raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
[ 36.580175] page dumped because: kasan: bad access detected
[ 36.581994]
[ 36.582548] Memory state around the buggy address:
[ 36.583983] ffff88800595ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
[ 36.586240] ffff888005960000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 36.588884] >ffff888005960080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 36.591071] ^
[ 36.593295] ffff888005960100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 36.595705] ffff888005960180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 36.598026] ==================================================================
[ 36.600224] Disabling lock debugging due to kernel taint
[ 36.602681] general protection fault, probably for non-canonical address 0x43600a000000060I
[ 36.607129] CPU: 0 PID: 49 Comm: kworker/0:2 Tainted: G B 6.2.0-rc3-15798-8
[ 36.611115] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g15584
[ 36.615026] Workqueue: events do_submit_urb
[ 36.616290] RIP: 0010:_raw_spin_lock_irqsave+0x8a/0xd0
[ 36.618107] Code: 24 00 00 00 00 48 89 df be 04 00 00 00 e8 9e b5 c6 fe 48 89 ef be 04 00 5
[ 36.623522] RSP: 0018:ffff888004b6fcf0 EFLAGS: 00010046
[ 36.625072] RAX: 0000000000000000 RBX: 043600a000000060 RCX: ffffffff9fc0e0d7
[ 36.627206] RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffff888004b6fcf0
[ 36.629813] RBP: ffff888004b6fcf0 R08: dffffc0000000000 R09: ffffed100096df9f
[ 36.631974] R10: dfffe9100096dfa0 R11: 1ffff1100096df9e R12: ffff888005960020
[ 36.634285] R13: ffff8880059600f0 R14: 0000000000000246 R15: 0000000000000001
[ 36.636438] FS: 0000000000000000(0000) GS:ffff88806d600000(0000) knlGS:0000000000000000
[ 36.639092] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 36.640951] CR2: 00007f07476819a3 CR3: 0000000004a34000 CR4: 00000000000006f0
[ 36.643411] Call Trace:
[ 36.644215] <TASK>
[ 36.644902] smscore_getbuffer+0x3e/0x1e0
[ 36.646147] do_submit_urb+0x4f/0x190
[ 36.647449] process_one_work+0x34c/0x5b0
[ 36.648777] worker_thread+0x4b7/0x890
[ 36.649984] ? worker_clr_flags+0x90/0x90
[ 36.651166] kthread+0x166/0x190
[ 36.652151] ? kthread_blkcg+0x50/0x50
[ 36.653547] ret_from_fork+0x22/0x30
[ 36.655051] </TASK>
[ 36.655733] Modules linked in:
[ 36.656787] ---[ end trace 0000000000000000 ]---
[ 36.658328] RIP: 0010:_raw_spin_lock_irqsave+0x8a/0xd0
[ 36.660045] Code: 24 00 00 00 00 48 89 df be 04 00 00 00 e8 9e b5 c6 fe 48 89 ef be 04 00 5
[ 36.665730] RSP: 0018:ffff888004b6fcf0 EFLAGS: 00010046
[ 36.667448] RAX: 0000000000000000 RBX: 043600a000000060 RCX: ffffffff9fc0e0d7
[ 36.669675] RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffff888004b6fcf0
[ 36.672645] RBP: ffff888004b6fcf0 R08: dffffc0000000000 R09: ffffed100096df9f
[ 36.674921] R10: dfffe9100096dfa0 R11: 1ffff1100096df9e R12: ffff888005960020
[ 36.677034] R13: ffff8880059600f0 R14: 0000000000000246 R15: 0000000000000001
[ 36.679184] FS: 0000000000000000(0000) GS:ffff88806d600000(0000) knlGS:0000000000000000
[ 36.681655] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 36.683383] CR2: 00007f07476819a3 CR3: 0000000004a34000 CR4: 00000000000006f0
[ 36.685733] Kernel panic - not syncing: Fatal exception
[ 36.688585] Kernel Offset: 0x1d400000 from 0xffffffff81000000 (relocation range: 0xfffffff)
[ 36.692199] ---[ end Kernel panic - not syncing: Fatal exception ]---
When the siano device is plugged in, it may call the following functions
to initialize the device.
smsusb_probe()-->smsusb_init_device()-->smscore_start_device().
When smscore_start_device() gets failed, the function smsusb_term_device()
will be called and smsusb_device_t will be deallocated. Although we use
usb_kill_urb() in smsusb_stop_streaming() to cancel transfer requests
and wait for them to finish, the worker threads that are scheduled by
smsusb_onresponse() may be still running. As a result, the UAF bugs
could happen.
We add cancel_work_sync() in smsusb_stop_streaming() in order that the
worker threads could finish before the smsusb_device_t is deallocated.
Fixes: dd47fbd40e6e ("[media] smsusb: don't sleep while atomic")
Signed-off-by: Duoming Zhou <[email protected]>
---
drivers/media/usb/siano/smsusb.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c
index fe9c7b3a950..6f443c542c6 100644
--- a/drivers/media/usb/siano/smsusb.c
+++ b/drivers/media/usb/siano/smsusb.c
@@ -179,6 +179,7 @@ static void smsusb_stop_streaming(struct smsusb_device_t *dev)
for (i = 0; i < MAX_URBS; i++) {
usb_kill_urb(&dev->surbs[i].urb);
+ cancel_work_sync(&dev->surbs[i].wq);
if (dev->surbs[i].cb) {
smscore_putbuffer(dev->coredev, dev->surbs[i].cb);
--
2.17.1