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

From: Andrey Konovalov
Date: Wed Aug 21 2019 - 08:55:40 EST


On Wed, Aug 21, 2019 at 2:54 PM Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote:
>
> 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

#syz test: https://github.com/google/kasan.git 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);