KASAN: slab-out-of-bounds Write in lg4ff_init

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: e96407b4 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=144c21dc600000
kernel config: https://syzkaller.appspot.com/x/.config?x=cfa2c18fb6a8068e
dashboard link: https://syzkaller.appspot.com/bug?extid=94e2b9e9c7d1dd332345
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=169e8542600000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10ec8262600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+94e2b9...@syzkaller.appspotmail.com

usb 1-1: config 0 interface 0 altsetting 0 has 1 endpoint descriptor,
different from the interface descriptor's value: 9
usb 1-1: New USB device found, idVendor=046d, idProduct=c298, bcdDevice=
0.00
usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
usb 1-1: config 0 descriptor??
logitech 0003:046D:C298.0001: unknown main item tag 0x0
logitech 0003:046D:C298.0001: unknown main item tag 0x0
logitech 0003:046D:C298.0001: hidraw0: USB HID v0.00 Device [HID 046d:c298]
on usb-dummy_hcd.0-1/input0
==================================================================
BUG: KASAN: slab-out-of-bounds in set_bit
include/asm-generic/bitops-instrumented.h:28 [inline]
BUG: KASAN: slab-out-of-bounds in lg4ff_init+0x89c/0x1800
drivers/hid/hid-lg4ff.c:1331
Write of size 8 at addr ffff8881d81fe9c0 by task kworker/1:2/83

CPU: 1 PID: 83 Comm: kworker/1:2 Not tainted 5.3.0-rc2+ #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xca/0x13e lib/dump_stack.c:113
print_address_description+0x6a/0x32c mm/kasan/report.c:351
__kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482
kasan_report+0xe/0x12 mm/kasan/common.c:612
check_memory_region_inline mm/kasan/generic.c:185 [inline]
check_memory_region+0x128/0x190 mm/kasan/generic.c:192
set_bit include/asm-generic/bitops-instrumented.h:28 [inline]
lg4ff_init+0x89c/0x1800 drivers/hid/hid-lg4ff.c:1331
lg_probe+0x3b3/0x890 drivers/hid/hid-lg.c:850
hid_device_probe+0x2be/0x3f0 drivers/hid/hid-core.c:2209
really_probe+0x281/0x650 drivers/base/dd.c:548
driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
__device_attach+0x217/0x360 drivers/base/dd.c:882
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
device_add+0xae6/0x16f0 drivers/base/core.c:2114
hid_add_device+0x33c/0x990 drivers/hid/hid-core.c:2365
usbhid_probe+0xa81/0xfa0 drivers/hid/usbhid/hid-core.c:1386
usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
really_probe+0x281/0x650 drivers/base/dd.c:548
driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
__device_attach+0x217/0x360 drivers/base/dd.c:882
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
device_add+0xae6/0x16f0 drivers/base/core.c:2114
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+0x281/0x650 drivers/base/dd.c:548
driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
__device_attach+0x217/0x360 drivers/base/dd.c:882
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
device_add+0xae6/0x16f0 drivers/base/core.c:2114
usb_new_device.cold+0x6a4/0xe79 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+0x1b5c/0x3640 drivers/usb/core/hub.c:5441
process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
worker_thread+0x96/0xe20 kernel/workqueue.c:2415
kthread+0x318/0x420 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Allocated by task 83:
save_stack+0x1b/0x80 mm/kasan/common.c:69
set_track mm/kasan/common.c:77 [inline]
__kasan_kmalloc mm/kasan/common.c:487 [inline]
__kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:460
kmalloc include/linux/slab.h:552 [inline]
kzalloc include/linux/slab.h:748 [inline]
hidraw_connect+0x4b/0x3e0 drivers/hid/hidraw.c:513
hid_connect+0x5c7/0xbb0 drivers/hid/hid-core.c:1885
hid_hw_start drivers/hid/hid-core.c:1981 [inline]
hid_hw_start+0xa2/0x130 drivers/hid/hid-core.c:1972
lg_probe+0x2a4/0x890 drivers/hid/hid-lg.c:806
hid_device_probe+0x2be/0x3f0 drivers/hid/hid-core.c:2209
really_probe+0x281/0x650 drivers/base/dd.c:548
driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
__device_attach+0x217/0x360 drivers/base/dd.c:882
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
device_add+0xae6/0x16f0 drivers/base/core.c:2114
hid_add_device+0x33c/0x990 drivers/hid/hid-core.c:2365
usbhid_probe+0xa81/0xfa0 drivers/hid/usbhid/hid-core.c:1386
usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
really_probe+0x281/0x650 drivers/base/dd.c:548
driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
__device_attach+0x217/0x360 drivers/base/dd.c:882
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
device_add+0xae6/0x16f0 drivers/base/core.c:2114
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+0x281/0x650 drivers/base/dd.c:548
driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
__device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
__device_attach+0x217/0x360 drivers/base/dd.c:882
bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
device_add+0xae6/0x16f0 drivers/base/core.c:2114
usb_new_device.cold+0x6a4/0xe79 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+0x1b5c/0x3640 drivers/usb/core/hub.c:5441
process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
worker_thread+0x96/0xe20 kernel/workqueue.c:2415
kthread+0x318/0x420 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 12:
save_stack+0x1b/0x80 mm/kasan/common.c:69
set_track mm/kasan/common.c:77 [inline]
__kasan_slab_free+0x130/0x180 mm/kasan/common.c:449
slab_free_hook mm/slub.c:1423 [inline]
slab_free_freelist_hook mm/slub.c:1470 [inline]
slab_free mm/slub.c:3012 [inline]
kfree+0xe4/0x2f0 mm/slub.c:3953
blk_free_flush_queue+0x3f/0x4c block/blk-flush.c:500
blk_mq_hw_sysfs_release+0x98/0x160 block/blk-mq-sysfs.c:43
kobject_cleanup lib/kobject.c:693 [inline]
kobject_release lib/kobject.c:722 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x171/0x280 lib/kobject.c:739
blk_mq_release+0x258/0x3f0 block/blk-mq.c:2677
__blk_release_queue+0x1ba/0x320 block/blk-sysfs.c:900
process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
worker_thread+0x96/0xe20 kernel/workqueue.c:2415
kthread+0x318/0x420 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8881d81fe900
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 0 bytes to the right of
192-byte region [ffff8881d81fe900, ffff8881d81fe9c0)
The buggy address belongs to the page:
page:ffffea0007607f80 refcount:1 mapcount:0 mapping:ffff8881da002a00
index:0x0
flags: 0x200000000000200(slab)
raw: 0200000000000200 ffffea000760f000 0000000400000004 ffff8881da002a00
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8881d81fe880: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
ffff8881d81fe900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffff8881d81fe980: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
^
ffff8881d81fea00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8881d81fea80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


---
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 syzk...@googlegroups.com.

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

[Oliver Neukum]

Am Montag, den 05.08.2019, 05:38 -0700 schrieb syzbot:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: e96407b4 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=144c21dc600000
> kernel config: https://syzkaller.appspot.com/x/.config?x=cfa2c18fb6a8068e
> dashboard link: https://syzkaller.appspot.com/bug?extid=94e2b9e9c7d1dd332345
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=169e8542600000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10ec8262600000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+94e2b9...@syzkaller.appspotmail.com
>
> usb 1-1: config 0 interface 0 altsetting 0 has 1 endpoint descriptor,
> different from the interface descriptor's value: 9
> usb 1-1: New USB device found, idVendor=046d, idProduct=c298, bcdDevice=
> 0.00
> usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
> usb 1-1: config 0 descriptor??
> logitech 0003:046D:C298.0001: unknown main item tag 0x0
> logitech 0003:046D:C298.0001: unknown main item tag 0x0
> logitech 0003:046D:C298.0001: hidraw0: USB HID v0.00 Device [HID 046d:c298]
> on usb-dummy_hcd.0-1/input0

> BUG: KASAN: slab-out-of-bounds in set_bit
> include/asm-generic/bitops-instrumented.h:28 [inline]

#syz test: https://github.com/google/kasan.git e96407b4

From 7e7f8ce9108b69613f8bb4ff2f95c258e22c3228 Mon Sep 17 00:00:00 2001
From: Oliver Neukum <one...@suse.com>
Date: Mon, 5 Aug 2019 16:14:47 +0200
Subject: [PATCH] hid-lg4ff: sanity check for offsets of FF effects

Malicious devices could provide huge offsets which would lead
to setting bits in random kernel memory. Adding a sanity check.

Reported-by: syzbot+94e2b9...@syzkaller.appspotmail.com
Signed-off-by: Oliver Neukum <one...@suse.com>
---
drivers/hid/hid-lg4ff.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
index cefba038520c..f9572750d889 100644
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -1327,8 +1327,12 @@ int lg4ff_init(struct hid_device *hid)
}

/* Set supported force feedback capabilities */
+ error = -ENODEV;
for (j = 0; lg4ff_devices[i].ff_effects[j] >= 0; j++)
- set_bit(lg4ff_devices[i].ff_effects[j], dev->ffbit);
+ if (lg4ff_devices[i].ff_effects[j] <= 15)
+ set_bit(lg4ff_devices[i].ff_effects[j], dev->ffbit);
+ else
+ goto err_init;

error = input_ff_create_memless(dev, NULL, lg4ff_play);

--
2.16.4

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger
crash:

Reported-and-tested-by:
syzbot+94e2b9...@syzkaller.appspotmail.com

Tested on:

commit: e96407b4 usb-fuzzer: main usb gadget fuzzer driver
git tree: https://github.com/google/kasan.git

kernel config: https://syzkaller.appspot.com/x/.config?x=cfa2c18fb6a8068e

compiler: gcc (GCC) 9.0.0 20181231 (experimental)

patch: https://syzkaller.appspot.com/x/patch.diff?x=16318b3a600000

Note: testing is done by a robot and is best-effort only.

[Andrey Konovalov]

Can't ff_effects have one of the FF_CONSTANT, FF_PERIODIC, etc.
values? Those are 0x50, 0x51, ... Or maybe I'm just misunderstanding
something. Are those ff_effects provided by the device?

[Oliver Neukum]

You are correct. It is a bitmap. Next patch is in the works.

Reagrds
Oliver

[Oliver Neukum]

Am Montag, den 05.08.2019, 05:38 -0700 schrieb syzbot:

> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: e96407b4 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=144c21dc600000
> kernel config: https://syzkaller.appspot.com/x/.config?x=cfa2c18fb6a8068e
> dashboard link: https://syzkaller.appspot.com/bug?extid=94e2b9e9c7d1dd332345
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=169e8542600000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10ec8262600000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+94e2b9...@syzkaller.appspotmail.com
>
> usb 1-1: config 0 interface 0 altsetting 0 has 1 endpoint descriptor,
> different from the interface descriptor's value: 9
> usb 1-1: New USB device found, idVendor=046d, idProduct=c298, bcdDevice=
> 0.00
> usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
> usb 1-1: config 0 descriptor??
> logitech 0003:046D:C298.0001: unknown main item tag 0x0
> logitech 0003:046D:C298.0001: unknown main item tag 0x0
> logitech 0003:046D:C298.0001: hidraw0: USB HID v0.00 Device [HID 046d:c298]
> on usb-dummy_hcd.0-1/input0

> BUG: KASAN: slab-out-of-bounds in set_bit
> include/asm-generic/bitops-instrumented.h:28 [inline]

#syz test: https://github.com/google/kasan.git e96407b4

From 90b712f3e9b9a45996eb0dfe5f489a4502c9f843 Mon Sep 17 00:00:00 2001

From: Oliver Neukum <one...@suse.com>
Date: Mon, 5 Aug 2019 16:14:47 +0200
Subject: [PATCH] hid-lg4ff: sanity check for offsets of FF effects

Malicious devices could provide huge offsets which would lead
to setting bits in random kernel memory. Adding a sanity check.

Reported-by: syzbot+94e2b9...@syzkaller.appspotmail.com
Signed-off-by: Oliver Neukum <one...@suse.com>
---
drivers/hid/hid-lg4ff.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c

index cefba038520c..9e63da793a0d 100644

--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -1327,8 +1327,12 @@ int lg4ff_init(struct hid_device *hid)
}

/* Set supported force feedback capabilities */
+ error = -ENODEV;
for (j = 0; lg4ff_devices[i].ff_effects[j] >= 0; j++)
- set_bit(lg4ff_devices[i].ff_effects[j], dev->ffbit);

+ if (lg4ff_devices[i].ff_effects[j] < FF_CNT)

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer still triggered
crash:
KASAN: slab-out-of-bounds Write in lg4ff_init

logitech 0003:046D:C298.0001: unknown main item tag 0x0
logitech 0003:046D:C298.0001: unknown main item tag 0x0
logitech 0003:046D:C298.0001: hidraw0: USB HID v0.00 Device [HID 046d:c298]

on usb-dummy_hcd.2-1/input0
==================================================================

BUG: KASAN: slab-out-of-bounds in set_bit
include/asm-generic/bitops-instrumented.h:28 [inline]

BUG: KASAN: slab-out-of-bounds in lg4ff_init+0x878/0x1800
drivers/hid/hid-lg4ff.c:1333
Write of size 8 at addr ffff8881d5d81dc0 by task kworker/0:0/5

CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.3.0-rc2+ #1

Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xca/0x13e lib/dump_stack.c:113
print_address_description+0x6a/0x32c mm/kasan/report.c:351
__kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482
kasan_report+0xe/0x12 mm/kasan/common.c:612
check_memory_region_inline mm/kasan/generic.c:185 [inline]
check_memory_region+0x128/0x190 mm/kasan/generic.c:192
set_bit include/asm-generic/bitops-instrumented.h:28 [inline]

lg4ff_init+0x878/0x1800 drivers/hid/hid-lg4ff.c:1333

Allocated by task 5:

Freed by task 0:
(stack is not available)

The buggy address belongs to the object at ffff8881d5d81d00

which belongs to the cache kmalloc-192 of size 192
The buggy address is located 0 bytes to the right of

192-byte region [ffff8881d5d81d00, ffff8881d5d81dc0)

The buggy address belongs to the page:

page:ffffea0007576040 refcount:1 mapcount:0 mapping:ffff8881da002a00
index:0x0
flags: 0x200000000000200(slab)
raw: 0200000000000200 dead000000000100 dead000000000122 ffff8881da002a00

raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:

ffff8881d5d81c80: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
ffff8881d5d81d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
> ffff8881d5d81d80: 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc
^
ffff8881d5d81e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff8881d5d81e80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================


Tested on:

commit: e96407b4 usb-fuzzer: main usb gadget fuzzer driver
git tree: https://github.com/google/kasan.git

console output: https://syzkaller.appspot.com/x/log.txt?x=10ccc0c2600000
kernel config: https://syzkaller.appspot.com/x/.config?x=cfa2c18fb6a8068e

compiler: gcc (GCC) 9.0.0 20181231 (experimental)

patch: https://syzkaller.appspot.com/x/patch.diff?x=17409626600000