Re: KASAN: use-after-free Read in hidraw_ioctl

[Andrey Konovalov]

On Tue, Jul 23, 2019 at 2:48 PM syzbot
<syzbot+ded1794a717e3b235226@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    6a3599ce usb-fuzzer: main usb gadget fuzzer driver
> git tree:       https://github.com/google/kasan.git usb-fuzzer
> console output: https://syzkaller.appspot.com/x/log.txt?x=107e7264600000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=700ca426ab83faae
> dashboard link: https://syzkaller.appspot.com/bug?extid=ded1794a717e3b235226
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=13b98b4c600000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1619b07c600000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+ded1794a717e3b235226@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> ==================================================================
> BUG: KASAN: use-after-free in hidraw_ioctl+0x609/0xaf0
> /drivers/hid/hidraw.c:380
> Read of size 4 at addr ffff8881d549a118 by task syz-executor073/2445
>
> CPU: 0 PID: 2445 Comm: syz-executor073 Not tainted 5.2.0-rc6+ #15
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Call Trace:
>   __dump_stack /lib/dump_stack.c:77 [inline]
>   dump_stack+0xca/0x13e /lib/dump_stack.c:113
>   print_address_description+0x67/0x231 /mm/kasan/report.c:188
>   __kasan_report.cold+0x1a/0x32 /mm/kasan/report.c:317
>   kasan_report+0xe/0x20 /mm/kasan/common.c:614
>   hidraw_ioctl+0x609/0xaf0 /drivers/hid/hidraw.c:380
>   vfs_ioctl /fs/ioctl.c:46 [inline]
>   file_ioctl /fs/ioctl.c:509 [inline]
>   do_vfs_ioctl+0xcda/0x12e0 /fs/ioctl.c:696
>   ksys_ioctl+0x9b/0xc0 /fs/ioctl.c:713
>   __do_sys_ioctl /fs/ioctl.c:720 [inline]
>   __se_sys_ioctl /fs/ioctl.c:718 [inline]
>   __x64_sys_ioctl+0x6f/0xb0 /fs/ioctl.c:718
>   do_syscall_64+0xb7/0x560 /arch/x86/entry/common.c:301
>   entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x451fd9
> Code: e8 ec e7 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7
> 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
> ff 0f 83 5b cb fb ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007f3144bd5ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
> RAX: ffffffffffffffda RBX: 00000000006e3c88 RCX: 0000000000451fd9
> RDX: 00000000200015c0 RSI: 0000000080044801 RDI: 0000000000000005
> RBP: 00000000006e3c80 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006e3c8c
> R13: 00007ffc64ba492f R14: 00007f3144bd69c0 R15: 0000000000000002
>
> Allocated by task 5:
>   save_stack+0x1b/0x80 /mm/kasan/common.c:71
>   set_track /mm/kasan/common.c:79 [inline]
>   __kasan_kmalloc /mm/kasan/common.c:489 [inline]
>   __kasan_kmalloc.constprop.0+0xbf/0xd0 /mm/kasan/common.c:462
>   kmalloc /./include/linux/slab.h:547 [inline]
>   kzalloc /./include/linux/slab.h:742 [inline]
>   hid_allocate_device+0x3e/0x480 /drivers/hid/hid-core.c:2389
>   usbhid_probe+0x23e/0xfa0 /drivers/hid/usbhid/hid-core.c:1321
>   usb_probe_interface+0x305/0x7a0 /drivers/usb/core/driver.c:361
>   really_probe+0x281/0x660 /drivers/base/dd.c:509
>   driver_probe_device+0x104/0x210 /drivers/base/dd.c:670
>   __device_attach_driver+0x1c2/0x220 /drivers/base/dd.c:777
>   bus_for_each_drv+0x15c/0x1e0 /drivers/base/bus.c:454
>   __device_attach+0x217/0x360 /drivers/base/dd.c:843
>   bus_probe_device+0x1e4/0x290 /drivers/base/bus.c:514
>   device_add+0xae6/0x16f0 /drivers/base/core.c:2111
>   usb_set_configuration+0xdf6/0x1670 /drivers/usb/core/message.c:2023
>   generic_probe+0x9d/0xd5 /drivers/usb/core/generic.c:210
>   usb_probe_device+0x99/0x100 /drivers/usb/core/driver.c:266
>   really_probe+0x281/0x660 /drivers/base/dd.c:509
>   driver_probe_device+0x104/0x210 /drivers/base/dd.c:670
>   __device_attach_driver+0x1c2/0x220 /drivers/base/dd.c:777
>   bus_for_each_drv+0x15c/0x1e0 /drivers/base/bus.c:454
>   __device_attach+0x217/0x360 /drivers/base/dd.c:843
>   bus_probe_device+0x1e4/0x290 /drivers/base/bus.c:514
>   device_add+0xae6/0x16f0 /drivers/base/core.c:2111
>   usb_new_device.cold+0x6a4/0xe61 /drivers/usb/core/hub.c:2536
>   hub_port_connect /drivers/usb/core/hub.c:5098 [inline]
>   hub_port_connect_change /drivers/usb/core/hub.c:5213 [inline]
>   port_event /drivers/usb/core/hub.c:5359 [inline]
>   hub_event+0x1abd/0x3550 /drivers/usb/core/hub.c:5441
>   process_one_work+0x905/0x1570 /kernel/workqueue.c:2269
>   worker_thread+0x96/0xe20 /kernel/workqueue.c:2415
>   kthread+0x30b/0x410 /kernel/kthread.c:255
>   ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352
>
> Freed by task 1781:
>   save_stack+0x1b/0x80 /mm/kasan/common.c:71
>   set_track /mm/kasan/common.c:79 [inline]
>   __kasan_slab_free+0x130/0x180 /mm/kasan/common.c:451
>   slab_free_hook /mm/slub.c:1421 [inline]
>   slab_free_freelist_hook /mm/slub.c:1448 [inline]
>   slab_free /mm/slub.c:2994 [inline]
>   kfree+0xd7/0x280 /mm/slub.c:3949
>   device_release+0x71/0x200 /drivers/base/core.c:1064
>   kobject_cleanup /lib/kobject.c:691 [inline]
>   kobject_release /lib/kobject.c:720 [inline]
>   kref_put /./include/linux/kref.h:65 [inline]
>   kobject_put+0x171/0x280 /lib/kobject.c:737
>   put_device+0x1b/0x30 /drivers/base/core.c:2210
>   usbhid_disconnect+0x90/0xd0 /drivers/hid/usbhid/hid-core.c:1413
>   usb_unbind_interface+0x1bd/0x8a0 /drivers/usb/core/driver.c:423
>   __device_release_driver /drivers/base/dd.c:1081 [inline]
>   device_release_driver_internal+0x404/0x4c0 /drivers/base/dd.c:1112
>   bus_remove_device+0x2dc/0x4a0 /drivers/base/bus.c:556
>   device_del+0x460/0xb80 /drivers/base/core.c:2274
>   usb_disable_device+0x211/0x690 /drivers/usb/core/message.c:1237
>   usb_disconnect+0x284/0x830 /drivers/usb/core/hub.c:2199
>   hub_port_connect /drivers/usb/core/hub.c:4949 [inline]
>   hub_port_connect_change /drivers/usb/core/hub.c:5213 [inline]
>   port_event /drivers/usb/core/hub.c:5359 [inline]
>   hub_event+0x13bd/0x3550 /drivers/usb/core/hub.c:5441
>   process_one_work+0x905/0x1570 /kernel/workqueue.c:2269
>   worker_thread+0x96/0xe20 /kernel/workqueue.c:2415
>   kthread+0x30b/0x410 /kernel/kthread.c:255
>   ret_from_fork+0x24/0x30 /arch/x86/entry/entry_64.S:352
>
> The buggy address belongs to the object at ffff8881d549a100
>   which belongs to the cache kmalloc-8k of size 8192
> The buggy address is located 24 bytes inside of
>   8192-byte region [ffff8881d549a100, ffff8881d549c100)
> The buggy address belongs to the page:
> page:ffffea0007552600 refcount:1 mapcount:0 mapping:ffff8881dac02400
> index:0x0 compound_mapcount: 0
> flags: 0x200000000010200(slab|head)
> raw: 0200000000010200 dead000000000100 dead000000000200 ffff8881dac02400
> raw: 0000000000000000 0000000000030003 00000001ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
>   ffff8881d549a000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>   ffff8881d549a080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> > ffff8881d549a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>                              ^
>   ffff8881d549a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>   ffff8881d549a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> This bug is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxxx
>
> syzbot will keep track of this bug report. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> syzbot can test patches for this bug, for details see:
> https://goo.gl/tpsmEJ#testing-patches

Trying Alan's fix from another thread here:

#syz test: https://github.com/google/kasan.git usb-fuzzer 6a3599ce
Index: usb-devel/drivers/hid/hid-lg.c
===================================================================
--- usb-devel.orig/drivers/hid/hid-lg.c
+++ usb-devel/drivers/hid/hid-lg.c
@@ -818,7 +818,7 @@ static int lg_probe(struct hid_device *h
 
 		if (!buf) {
 			ret = -ENOMEM;
-			goto err_free;
+			goto err_stop;
 		}
 
 		ret = hid_hw_raw_request(hdev, buf[0], buf, sizeof(cbuf),
@@ -850,9 +850,12 @@ static int lg_probe(struct hid_device *h
 		ret = lg4ff_init(hdev);
 
 	if (ret)
-		goto err_free;
+		goto err_stop;
 
 	return 0;
+
+err_stop:
+	hid_hw_stop(hdev);
 err_free:
 	kfree(drv_data);
 	return ret;
@@ -863,8 +866,7 @@ static void lg_remove(struct hid_device
 	struct lg_drv_data *drv_data = hid_get_drvdata(hdev);
 	if (drv_data->quirks & LG_FF4)
 		lg4ff_deinit(hdev);
-	else
-		hid_hw_stop(hdev);
+	hid_hw_stop(hdev);
 	kfree(drv_data);
 }
 
Index: usb-devel/drivers/hid/hid-lg4ff.c
===================================================================
--- usb-devel.orig/drivers/hid/hid-lg4ff.c
+++ usb-devel/drivers/hid/hid-lg4ff.c
@@ -1477,7 +1477,6 @@ int lg4ff_deinit(struct hid_device *hid)
 		}
 	}
 #endif
-	hid_hw_stop(hid);
 	drv_data->device_props = NULL;
 
 	kfree(entry);