Re: usb/misc/usbtest: null-ptr-deref in usbtest_probe/get_endpoints

[Andrey Konovalov]

On Thu, Sep 28, 2017 at 7:01 PM, Alan Stern  wrote:
> On Thu, 28 Sep 2017, Andrey Konovalov wrote:
>
>> Hi!
>>
>> I've got the following report while fuzzing the kernel with syzkaller.
>>
>> On commit dc972a67cc54585bd83ad811c4e9b6ab3dcd427e (4.14-rc2+).
>>
>> It seems that out pointer ends up being NULL and kernel crashes on
>> access to out->desc.bEndpointAddress.
>>
>> gadgetfs: bound to dummy_udc driver
>> usb 1-1: new full-speed USB device number 2 using dummy_hcd
>> gadgetfs: connected
>> gadgetfs: disconnected
>> gadgetfs: connected
>> usb 1-1: config 2 interface 0 altsetting 206 endpoint 0x81 has invalid
>> maxpacket 2040, setting to 64
>> usb 1-1: config 2 interface 0 altsetting 206 has an invalid endpoint
>> with address 0xFF, skipping
>> usb 1-1: config 2 interface 0 altsetting 206 endpoint 0x5 has an
>> invalid bInterval 255, changing to 4
>> usb 1-1: config 2 interface 0 has no altsetting 0
>> usb 1-1: New USB device found, idVendor=0525, idProduct=a4a0
>> usb 1-1: New USB device strings: Mfr=0, Product=185, SerialNumber=1
>> usb 1-1: Product: a
>> usb 1-1: SerialNumber: a
>> gadgetfs: configuration #2
>> kasan: CONFIG_KASAN_INLINE enabled
>> kasan: GPF could be caused by NULL-ptr deref or user memory access
>> general protection fault:  [#1] PREEMPT SMP KASAN
>> Modules linked in:
>> CPU: 1 PID: 1845 Comm: kworker/1:2 Not tainted
>> 4.14.0-rc2-42664-gaf7d1481b3cb #297
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> Workqueue: usb_hub_wq hub_event
>> task: 880064328000 task.stack: 880064398000
>> RIP: 0010:get_endpoints drivers/usb/misc/usbtest.c:208
>> RIP: 0010:usbtest_probe+0x114f/0x1ef0 drivers/usb/misc/usbtest.c:2706
>
> This looks like a simple logic error.
>
> Alan Stern

Hi Alan,

This fixes it.

Tested-by: Andrey Konovalov 

Thanks!

>
>
>
> Index: usb-4.x/drivers/usb/misc/usbtest.c
> ===
> --- usb-4.x.orig/drivers/usb/misc/usbtest.c
> +++ usb-4.x/drivers/usb/misc/usbtest.c
> @@ -202,12 +202,13 @@ found:
> return tmp;
> }
>
> -   if (in) {
> +   if (in)
> dev->in_pipe = usb_rcvbulkpipe(udev,
> in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
> +   if (out)
> dev->out_pipe = usb_sndbulkpipe(udev,
> out->desc.bEndpointAddress & 
> USB_ENDPOINT_NUMBER_MASK);
> -   }
> +
> if (iso_in) {
> dev->iso_in = _in->desc;
> dev->in_iso_pipe = usb_rcvisocpipe(udev,
>

Re: usb/misc/usbtest: null-ptr-deref in usbtest_probe/get_endpoints

[Andrey Konovalov]

On Thu, Sep 28, 2017 at 7:01 PM, Alan Stern  wrote:
> On Thu, 28 Sep 2017, Andrey Konovalov wrote:
>
>> Hi!
>>
>> I've got the following report while fuzzing the kernel with syzkaller.
>>
>> On commit dc972a67cc54585bd83ad811c4e9b6ab3dcd427e (4.14-rc2+).
>>
>> It seems that out pointer ends up being NULL and kernel crashes on
>> access to out->desc.bEndpointAddress.
>>
>> gadgetfs: bound to dummy_udc driver
>> usb 1-1: new full-speed USB device number 2 using dummy_hcd
>> gadgetfs: connected
>> gadgetfs: disconnected
>> gadgetfs: connected
>> usb 1-1: config 2 interface 0 altsetting 206 endpoint 0x81 has invalid
>> maxpacket 2040, setting to 64
>> usb 1-1: config 2 interface 0 altsetting 206 has an invalid endpoint
>> with address 0xFF, skipping
>> usb 1-1: config 2 interface 0 altsetting 206 endpoint 0x5 has an
>> invalid bInterval 255, changing to 4
>> usb 1-1: config 2 interface 0 has no altsetting 0
>> usb 1-1: New USB device found, idVendor=0525, idProduct=a4a0
>> usb 1-1: New USB device strings: Mfr=0, Product=185, SerialNumber=1
>> usb 1-1: Product: a
>> usb 1-1: SerialNumber: a
>> gadgetfs: configuration #2
>> kasan: CONFIG_KASAN_INLINE enabled
>> kasan: GPF could be caused by NULL-ptr deref or user memory access
>> general protection fault:  [#1] PREEMPT SMP KASAN
>> Modules linked in:
>> CPU: 1 PID: 1845 Comm: kworker/1:2 Not tainted
>> 4.14.0-rc2-42664-gaf7d1481b3cb #297
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> Workqueue: usb_hub_wq hub_event
>> task: 880064328000 task.stack: 880064398000
>> RIP: 0010:get_endpoints drivers/usb/misc/usbtest.c:208
>> RIP: 0010:usbtest_probe+0x114f/0x1ef0 drivers/usb/misc/usbtest.c:2706
>
> This looks like a simple logic error.
>
> Alan Stern

Hi Alan,

This fixes it.

Tested-by: Andrey Konovalov 

Thanks!

>
>
>
> Index: usb-4.x/drivers/usb/misc/usbtest.c
> ===
> --- usb-4.x.orig/drivers/usb/misc/usbtest.c
> +++ usb-4.x/drivers/usb/misc/usbtest.c
> @@ -202,12 +202,13 @@ found:
> return tmp;
> }
>
> -   if (in) {
> +   if (in)
> dev->in_pipe = usb_rcvbulkpipe(udev,
> in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
> +   if (out)
> dev->out_pipe = usb_sndbulkpipe(udev,
> out->desc.bEndpointAddress & 
> USB_ENDPOINT_NUMBER_MASK);
> -   }
> +
> if (iso_in) {
> dev->iso_in = _in->desc;
> dev->in_iso_pipe = usb_rcvisocpipe(udev,
>

Re: usb/misc/usbtest: null-ptr-deref in usbtest_probe/get_endpoints

[Alan Stern]

On Thu, 28 Sep 2017, Andrey Konovalov wrote:

> Hi!
> 
> I've got the following report while fuzzing the kernel with syzkaller.
> 
> On commit dc972a67cc54585bd83ad811c4e9b6ab3dcd427e (4.14-rc2+).
> 
> It seems that out pointer ends up being NULL and kernel crashes on
> access to out->desc.bEndpointAddress.
> 
> gadgetfs: bound to dummy_udc driver
> usb 1-1: new full-speed USB device number 2 using dummy_hcd
> gadgetfs: connected
> gadgetfs: disconnected
> gadgetfs: connected
> usb 1-1: config 2 interface 0 altsetting 206 endpoint 0x81 has invalid
> maxpacket 2040, setting to 64
> usb 1-1: config 2 interface 0 altsetting 206 has an invalid endpoint
> with address 0xFF, skipping
> usb 1-1: config 2 interface 0 altsetting 206 endpoint 0x5 has an
> invalid bInterval 255, changing to 4
> usb 1-1: config 2 interface 0 has no altsetting 0
> usb 1-1: New USB device found, idVendor=0525, idProduct=a4a0
> usb 1-1: New USB device strings: Mfr=0, Product=185, SerialNumber=1
> usb 1-1: Product: a
> usb 1-1: SerialNumber: a
> gadgetfs: configuration #2
> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault:  [#1] PREEMPT SMP KASAN
> Modules linked in:
> CPU: 1 PID: 1845 Comm: kworker/1:2 Not tainted
> 4.14.0-rc2-42664-gaf7d1481b3cb #297
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> Workqueue: usb_hub_wq hub_event
> task: 880064328000 task.stack: 880064398000
> RIP: 0010:get_endpoints drivers/usb/misc/usbtest.c:208
> RIP: 0010:usbtest_probe+0x114f/0x1ef0 drivers/usb/misc/usbtest.c:2706

This looks like a simple logic error.

Alan Stern



Index: usb-4.x/drivers/usb/misc/usbtest.c
===
--- usb-4.x.orig/drivers/usb/misc/usbtest.c
+++ usb-4.x/drivers/usb/misc/usbtest.c
@@ -202,12 +202,13 @@ found:
return tmp;
}
 
-   if (in) {
+   if (in)
dev->in_pipe = usb_rcvbulkpipe(udev,
in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
+   if (out)
dev->out_pipe = usb_sndbulkpipe(udev,
out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
-   }
+
if (iso_in) {
dev->iso_in = _in->desc;
dev->in_iso_pipe = usb_rcvisocpipe(udev,

Re: usb/misc/usbtest: null-ptr-deref in usbtest_probe/get_endpoints

[Alan Stern]

On Thu, 28 Sep 2017, Andrey Konovalov wrote:

> Hi!
> 
> I've got the following report while fuzzing the kernel with syzkaller.
> 
> On commit dc972a67cc54585bd83ad811c4e9b6ab3dcd427e (4.14-rc2+).
> 
> It seems that out pointer ends up being NULL and kernel crashes on
> access to out->desc.bEndpointAddress.
> 
> gadgetfs: bound to dummy_udc driver
> usb 1-1: new full-speed USB device number 2 using dummy_hcd
> gadgetfs: connected
> gadgetfs: disconnected
> gadgetfs: connected
> usb 1-1: config 2 interface 0 altsetting 206 endpoint 0x81 has invalid
> maxpacket 2040, setting to 64
> usb 1-1: config 2 interface 0 altsetting 206 has an invalid endpoint
> with address 0xFF, skipping
> usb 1-1: config 2 interface 0 altsetting 206 endpoint 0x5 has an
> invalid bInterval 255, changing to 4
> usb 1-1: config 2 interface 0 has no altsetting 0
> usb 1-1: New USB device found, idVendor=0525, idProduct=a4a0
> usb 1-1: New USB device strings: Mfr=0, Product=185, SerialNumber=1
> usb 1-1: Product: a
> usb 1-1: SerialNumber: a
> gadgetfs: configuration #2
> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault:  [#1] PREEMPT SMP KASAN
> Modules linked in:
> CPU: 1 PID: 1845 Comm: kworker/1:2 Not tainted
> 4.14.0-rc2-42664-gaf7d1481b3cb #297
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> Workqueue: usb_hub_wq hub_event
> task: 880064328000 task.stack: 880064398000
> RIP: 0010:get_endpoints drivers/usb/misc/usbtest.c:208
> RIP: 0010:usbtest_probe+0x114f/0x1ef0 drivers/usb/misc/usbtest.c:2706

This looks like a simple logic error.

Alan Stern



Index: usb-4.x/drivers/usb/misc/usbtest.c
===
--- usb-4.x.orig/drivers/usb/misc/usbtest.c
+++ usb-4.x/drivers/usb/misc/usbtest.c
@@ -202,12 +202,13 @@ found:
return tmp;
}
 
-   if (in) {
+   if (in)
dev->in_pipe = usb_rcvbulkpipe(udev,
in->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
+   if (out)
dev->out_pipe = usb_sndbulkpipe(udev,
out->desc.bEndpointAddress & USB_ENDPOINT_NUMBER_MASK);
-   }
+
if (iso_in) {
dev->iso_in = _in->desc;
dev->in_iso_pipe = usb_rcvisocpipe(udev,

usb/misc/usbtest: null-ptr-deref in usbtest_probe/get_endpoints

[Andrey Konovalov]

Hi!

I've got the following report while fuzzing the kernel with syzkaller.

On commit dc972a67cc54585bd83ad811c4e9b6ab3dcd427e (4.14-rc2+).

It seems that out pointer ends up being NULL and kernel crashes on
access to out->desc.bEndpointAddress.

gadgetfs: bound to dummy_udc driver
usb 1-1: new full-speed USB device number 2 using dummy_hcd
gadgetfs: connected
gadgetfs: disconnected
gadgetfs: connected
usb 1-1: config 2 interface 0 altsetting 206 endpoint 0x81 has invalid
maxpacket 2040, setting to 64
usb 1-1: config 2 interface 0 altsetting 206 has an invalid endpoint
with address 0xFF, skipping
usb 1-1: config 2 interface 0 altsetting 206 endpoint 0x5 has an
invalid bInterval 255, changing to 4
usb 1-1: config 2 interface 0 has no altsetting 0
usb 1-1: New USB device found, idVendor=0525, idProduct=a4a0
usb 1-1: New USB device strings: Mfr=0, Product=185, SerialNumber=1
usb 1-1: Product: a
usb 1-1: SerialNumber: a
gadgetfs: configuration #2
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault:  [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 1845 Comm: kworker/1:2 Not tainted
4.14.0-rc2-42664-gaf7d1481b3cb #297
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Workqueue: usb_hub_wq hub_event
task: 880064328000 task.stack: 880064398000
RIP: 0010:get_endpoints drivers/usb/misc/usbtest.c:208
RIP: 0010:usbtest_probe+0x114f/0x1ef0 drivers/usb/misc/usbtest.c:2706
RSP: 0018:88006439e358 EFLAGS: 00010246
RAX: dc00 RBX:  RCX: 11000c873c33
RDX:  RSI: 0006 RDI: 0002
RBP: 88006439e5e8 R08: 88006439dd60 R09: 11000c873bc5
R10: 880064328000 R11: 0005 R12: 88006197e698
R13: 880067755d28 R14: 88006439e5c0 R15: 88006782ddc0
FS:  () GS:88006c90() knlGS:
CS:  0010 DS:  ES:  CR0: 80050033
CR2: 20002e07 CR3: 639a9000 CR4: 06e0
Call Trace:
 usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361
 really_probe drivers/base/dd.c:413
 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557
 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653
 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463
 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710
 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757
 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523
 device_add+0xd0b/0x1660 drivers/base/core.c:1835
 usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932
 generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174
 usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266
 really_probe drivers/base/dd.c:413
 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557
 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653
 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463
 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710
 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757
 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523
 device_add+0xd0b/0x1660 drivers/base/core.c:1835
 usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457
 hub_port_connect drivers/usb/core/hub.c:4903
 hub_port_connect_change drivers/usb/core/hub.c:5009
 port_event drivers/usb/core/hub.c:5115
 hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195
 process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119
 worker_thread+0x221/0x1850 kernel/workqueue.c:2253
 kthread+0x3a1/0x470 kernel/kthread.c:231
 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431
Code: 8b bd 30 fe ff ff e8 d1 60 05 fe 48 b8 00 00 00 00 00 fc ff df
41 89 5f 10 49 8b 9e c0 fe ff ff 48 8d 7b 02 48 89 fa 48 c1 ea 03 <0f>
b6 04 02 48 89 fa 83 e2 07 38 d0 7f 09 84 c0 74 05 e8 ba 5f
RIP: usbtest_probe+0x114f/0x1ef0 RSP: 88006439e358
---[ end trace 005817b8c41d50d0 ]---

usb/misc/usbtest: null-ptr-deref in usbtest_probe/get_endpoints

[Andrey Konovalov]

Hi!

I've got the following report while fuzzing the kernel with syzkaller.

On commit dc972a67cc54585bd83ad811c4e9b6ab3dcd427e (4.14-rc2+).

It seems that out pointer ends up being NULL and kernel crashes on
access to out->desc.bEndpointAddress.

gadgetfs: bound to dummy_udc driver
usb 1-1: new full-speed USB device number 2 using dummy_hcd
gadgetfs: connected
gadgetfs: disconnected
gadgetfs: connected
usb 1-1: config 2 interface 0 altsetting 206 endpoint 0x81 has invalid
maxpacket 2040, setting to 64
usb 1-1: config 2 interface 0 altsetting 206 has an invalid endpoint
with address 0xFF, skipping
usb 1-1: config 2 interface 0 altsetting 206 endpoint 0x5 has an
invalid bInterval 255, changing to 4
usb 1-1: config 2 interface 0 has no altsetting 0
usb 1-1: New USB device found, idVendor=0525, idProduct=a4a0
usb 1-1: New USB device strings: Mfr=0, Product=185, SerialNumber=1
usb 1-1: Product: a
usb 1-1: SerialNumber: a
gadgetfs: configuration #2
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault:  [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 1845 Comm: kworker/1:2 Not tainted
4.14.0-rc2-42664-gaf7d1481b3cb #297
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Workqueue: usb_hub_wq hub_event
task: 880064328000 task.stack: 880064398000
RIP: 0010:get_endpoints drivers/usb/misc/usbtest.c:208
RIP: 0010:usbtest_probe+0x114f/0x1ef0 drivers/usb/misc/usbtest.c:2706
RSP: 0018:88006439e358 EFLAGS: 00010246
RAX: dc00 RBX:  RCX: 11000c873c33
RDX:  RSI: 0006 RDI: 0002
RBP: 88006439e5e8 R08: 88006439dd60 R09: 11000c873bc5
R10: 880064328000 R11: 0005 R12: 88006197e698
R13: 880067755d28 R14: 88006439e5c0 R15: 88006782ddc0
FS:  () GS:88006c90() knlGS:
CS:  0010 DS:  ES:  CR0: 80050033
CR2: 20002e07 CR3: 639a9000 CR4: 06e0
Call Trace:
 usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361
 really_probe drivers/base/dd.c:413
 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557
 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653
 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463
 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710
 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757
 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523
 device_add+0xd0b/0x1660 drivers/base/core.c:1835
 usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932
 generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174
 usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266
 really_probe drivers/base/dd.c:413
 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557
 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653
 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463
 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710
 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757
 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523
 device_add+0xd0b/0x1660 drivers/base/core.c:1835
 usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457
 hub_port_connect drivers/usb/core/hub.c:4903
 hub_port_connect_change drivers/usb/core/hub.c:5009
 port_event drivers/usb/core/hub.c:5115
 hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195
 process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119
 worker_thread+0x221/0x1850 kernel/workqueue.c:2253
 kthread+0x3a1/0x470 kernel/kthread.c:231
 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431
Code: 8b bd 30 fe ff ff e8 d1 60 05 fe 48 b8 00 00 00 00 00 fc ff df
41 89 5f 10 49 8b 9e c0 fe ff ff 48 8d 7b 02 48 89 fa 48 c1 ea 03 <0f>
b6 04 02 48 89 fa 83 e2 07 38 d0 7f 09 84 c0 74 05 e8 ba 5f
RIP: usbtest_probe+0x114f/0x1ef0 RSP: 88006439e358
---[ end trace 005817b8c41d50d0 ]---