Re: [PATCHv2] Check whether divisor is non-zero before division

From: shichao lai
Date: Thu May 23 2024 - 11:23:22 EST

On Thu, May 23, 2024 at 11:13 PM shichao lai <shichaorai@xxxxxxxxx> wrote:
>
> On Thu, May 23, 2024 at 10:15 PM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > On Thu, May 23, 2024 at 09:58:21AM -0400, Alan Stern wrote:
> > > On Thu, May 23, 2024 at 05:26:08PM +0800, Shichao Lai wrote:
> > > > Since uzonesize may be zero, so judgements for non-zero are nessesary in both place.
> > > > Previous check is moved out of loop, and one more check is added in alauda_write_lba.
> > > >
> > > > Reported-by: xingwei lee <xrivendell7@xxxxxxxxx>
> > > > Reported-by: yue sun <samsun1006219@xxxxxxxxx>
> > > > Signed-off-by: Shichao Lai <shichaorai@xxxxxxxxx>
> > > > ---
> > > > drivers/usb/storage/alauda.c | 4 ++++
> > > > 1 file changed, 4 insertions(+)
> > > >
> > > > diff --git a/drivers/usb/storage/alauda.c b/drivers/usb/storage/alauda.c
> > > > index 115f05a6201a..a6e60ef5cb0d 100644
> > > > --- a/drivers/usb/storage/alauda.c
> > > > +++ b/drivers/usb/storage/alauda.c
> > > > @@ -818,6 +818,8 @@ static int alauda_write_lba(struct us_data *us, u16 lba,
> > > > unsigned int blocksize = MEDIA_INFO(us).blocksize;
> > > > unsigned int lba_offset = lba % uzonesize;
> > > > unsigned int new_pba_offset;
> > > > + if (!uzonesize)
> > > > + return USB_STOR_TRANSPORT_ERROR;
> > > > unsigned int zone = lba / uzonesize;
> > > >
> > > > alauda_ensure_map_for_zone(us, zone);
> > > > @@ -923,6 +925,8 @@ static int alauda_read_data(struct us_data *us, unsigned long address,
> > > > unsigned int uzonesize = MEDIA_INFO(us).uzonesize;
> > > > struct scatterlist *sg;
> > > > int result;
> > > > + if (!uzonesize)
> > > > + return USB_STOR_TRANSPORT_ERROR;
> > > >
> > > > /*
> > > > * Since we only read in one block at a time, we have to create
> > >
> > > This is definitely NOT the right way to fix the bug!
> > >
> > > uzonesize is set once, when the device is probed, in
> > > alauda_init_media(). That is where the check belongs; if uzonesize is 0
> > > then the function should print a warning and return
> > > USB_STOR_TRANSPORT_ERROR, because the device is unusable.
> > >
> > > It's probably a good idea to check pagesize, blocksize, and zonesize at
> > > the same time, even though none of them are used for any divisions.
> >
> > Wait a minute. I just went through the code more carefully. It should
> > not be possible for uzonesize to be 0, because it is defined by:
> >
> > MEDIA_INFO(us).uzonesize = ((1 << media_info->zoneshift) / 128) * 125;
> >
> > where media_info->zoneshift is always a value between 8 and 12.
> >
> > So the whole idea behind this patch is misguided. The real problem is
> > to find out why uzonesize ended up being 0.
> >
> > (And it's not necessary to check pagesize, blocksize, or zonesize,
> > because none of them can ever be 0 either.)
> >
> > Alan Stern
>
> Thanks for your comprehensive analysis.
> I added some pr_info() to check the workflow, and I found that the
> uzonesize was not initialized in fact!
>
> The workflow is shown as below.
> Before alauda_read_data(), there are in fact many alauda_check_media(),
> but none of them enter the branch of alauda_init_media(), where
> uzonesize is set to nonzero value.
> The key branch condition is "status[0] & 0x08", which is always
> unsatisfied in this repro.
>
> ```
> alauda_transport
> alauda_check_media
> if (status[0] & 0x08) // not satisfied
> alauda_init_media()
> // initialize uzonesize
> alauda_read_data
> ```
>
> I also print status[0] before the branch, which may be helpful for you
> to analyze.
>
> The part you should focus on is the information beginning with
> "alauda_check_media".
> e.g. "alauda_check_media: before alauda_get_media_status, status[0]:
> 0000000000000000" means in alauda_check_media(), before calling
> alauda_get_media_status()
> It seems that alauda_get_media_status() will transform the status[0]
> to 0x0000000000000036, which doesn't satisfy the condition of
> "status[0] & 0x08".
> ===========
> root@syzkaller:~# ./exp
> [ 28.645451][ T2386] usb 1-1: new high-speed USB device number 2
> using dummy_hcd
> [ 28.885289][ T2386] usb 1-1: Using ep0 maxpacket: 16
> [ 29.005519][ T2386] usb 1-1: config 0 has an invalid interface
> number: 192 but max is 0
> [ 29.007448][ T2386] usb 1-1: config 0 has no interface number 0
> [ 29.008759][ T2386] usb 1-1: config 0 interface 192 altsetting 0
> endpoint 0x9 has invalid wMaxPacketSize 0
> [ 29.010799][ T2386] usb 1-1: config 0 interface 192 altsetting 0
> bulk endpoint 0x9 has invalid maxpacket 0
> [ 29.012467][ T2386] usb 1-1: config 0 interface 192 altsetting 0
> endpoint 0x8F has invalid maxpacket 59960, setting to 1024
> [ 29.012959][ T2386] usb 1-1: config 0 interface 192 altsetting 0
> bulk endpoint 0x8F has invalid maxpacket 1024
> [ 29.013413][ T2386] usb 1-1: New USB device found, idVendor=07b4,
> idProduct=010a, bcdDevice= 1.02
> [ 29.013809][ T2386] usb 1-1: New USB device strings: Mfr=0,
> Product=0, SerialNumber=0
> [ 29.015193][ T2386] usb 1-1: config 0 descriptor??
> [ 29.035791][ T4124] raw-gadget.0 gadget.0: fail, usb_ep_enable returned -22
> [ 29.057576][ T2386] ums-alauda 1-1:0.192: USB Mass Storage device detected
> [ 29.062276][ T2386] scsi host2: usb-storage 1-1:0.192
> [ 30.098931][ T2386] scsi 2:0:0:0: Direct-Access Olympus
> MAUSB-10 (Alauda 0102 PQ: 0 ANSI: 0 CCS
> [ 30.102903][ T4131] alauda_check_media: before
> alauda_get_media_status, status[0]: 0000000000000000
> [ 30.104297][ T2386] sd 2:0:0:0: Attached scsi generic sg2 type 0
> [ 30.135805][ T4131] alauda_get_media_status: data=54, rc=0
> [ 30.137113][ T4131] alauda_check_media: after
> alauda_get_media_status, status[0]: 0000000000000036
> [ 30.138991][ T4131] alauda_check_media: before init_media,
> status[0]: 0000000000000036
> [ 30.141727][ T4131] alauda_check_media: before
> alauda_get_media_status, status[0]: 0000000000000036
> [ 30.355544][ T4131] alauda_get_media_status: data=54, rc=0
> [ 30.356815][ T4131] alauda_check_media: after
> alauda_get_media_status, status[0]: 0000000000000036
> [ 30.358728][ T4131] alauda_check_media: before init_media,
> status[0]: 0000000000000036
> [ 30.361408][ T4131] alauda_check_media: before
> alauda_get_media_status, status[0]: 00000000000000ff
> [ 30.575607][ T4131] alauda_get_media_status: data=54, rc=0
> [ 30.576910][ T4131] alauda_check_media: after
> alauda_get_media_status, status[0]: 0000000000000036
> [ 30.578823][ T4131] alauda_check_media: before init_media,
> status[0]: 0000000000000036
> [ 30.580999][ T4131] alauda_check_media: before
> alauda_get_media_status, status[0]: 00000000000000ff
> [ 30.795625][ T4131] alauda_get_media_status: data=54, rc=0
> [ 30.796899][ T4131] alauda_check_media: after
> alauda_get_media_status, status[0]: 0000000000000036
> [ 30.798773][ T4131] alauda_check_media: before init_media,
> status[0]: 0000000000000036
> [ 30.801017][ T4131] alauda_check_media: before
> alauda_get_media_status, status[0]: 00000000000000ff
> [ 31.015362][ T4131] alauda_get_media_status: data=54, rc=0
> [ 31.016679][ T4131] alauda_check_media: after
> alauda_get_media_status, status[0]: 0000000000000036
> [ 31.018565][ T4131] alauda_check_media: before init_media,
> status[0]: 0000000000000036
> [ 31.020543][ T263] sd 2:0:0:0: [sdb] Very big device. Trying to
> use READ CAPACITY(16).
> [ 31.023323][ T263] sd 2:0:0:0: [sdb] Using 0xffffffff as device size
> [ 31.035382][ T2386] scsi 2:0:0:1: Direct-Access Olympus
> MAUSB-10 (Alauda 0102 PQ: 0 ANSI: 0 CCS
> [ 31.035466][ T4131] alauda_transport: before alauda_check_media
> [ 31.038810][ T4131] alauda_check_media: before
> alauda_get_media_status, status[0]: 0000000000000000
> [ 31.043663][ T2386] sd 2:0:0:1: Attached scsi generic sg3 type 0
> [ 31.235486][ T4131] alauda_get_media_status: data=54, rc=0
> [ 31.237015][ T4131] alauda_check_media: after
> alauda_get_media_status, status[0]: 0000000000000036
> [ 31.239266][ T4131] alauda_check_media: before init_media,
> status[0]: 0000000000000036
> [ 31.241273][ T4131] alauda_transport: after alauda_check_media ->
> alauda_read_data
> [ 31.243134][ T4131] alauda_read_data: 0
> [ 31.244148][ T4131] divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI

For ease of reproduction, I attach my kernel config and repro.c.
The kernel version is v6.9-rc7
gcc version: 11.4.0
// autogenerated by syzkaller (https://github.com/google/syzkaller)

#define _GNU_SOURCE

#include <endian.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#include <sys/types.h>
#include <unistd.h>

#include <linux/usb/ch9.h>

static unsigned long long procid;

static void sleep_ms(uint64_t ms)
{
usleep(ms * 1000);
}

#define MAX_FDS 30

#define USB_MAX_IFACE_NUM 4
#define USB_MAX_EP_NUM 32
#define USB_MAX_FDS 6

struct usb_endpoint_index {
struct usb_endpoint_descriptor desc;
int handle;
};

struct usb_iface_index {
struct usb_interface_descriptor* iface;
uint8_t bInterfaceNumber;
uint8_t bAlternateSetting;
uint8_t bInterfaceClass;
struct usb_endpoint_index eps[USB_MAX_EP_NUM];
int eps_num;
};

struct usb_device_index {
struct usb_device_descriptor* dev;
struct usb_config_descriptor* config;
uint8_t bDeviceClass;
uint8_t bMaxPower;
int config_length;
struct usb_iface_index ifaces[USB_MAX_IFACE_NUM];
int ifaces_num;
int iface_cur;
};

struct usb_info {
int fd;
struct usb_device_index index;
};

static struct usb_info usb_devices[USB_MAX_FDS];

static struct usb_device_index* lookup_usb_index(int fd)
{
for (int i = 0; i < USB_MAX_FDS; i++) {
if (__atomic_load_n(&usb_devices[i].fd, __ATOMIC_ACQUIRE) == fd)
return &usb_devices[i].index;
}
return NULL;
}

static int usb_devices_num;

static bool parse_usb_descriptor(const char* buffer, size_t length, struct usb_device_index* index)
{
if (length < sizeof(*index->dev) + sizeof(*index->config))
return false;
memset(index, 0, sizeof(*index));
index->dev = (struct usb_device_descriptor*)buffer;
index->config = (struct usb_config_descriptor*)(buffer + sizeof(*index->dev));
index->bDeviceClass = index->dev->bDeviceClass;
index->bMaxPower = index->config->bMaxPower;
index->config_length = length - sizeof(*index->dev);
index->iface_cur = -1;
size_t offset = 0;
while (true) {
if (offset + 1 >= length)
break;
uint8_t desc_length = buffer[offset];
uint8_t desc_type = buffer[offset + 1];
if (desc_length <= 2)
break;
if (offset + desc_length > length)
break;
if (desc_type == USB_DT_INTERFACE && index->ifaces_num < USB_MAX_IFACE_NUM) {
struct usb_interface_descriptor* iface = (struct usb_interface_descriptor*)(buffer + offset);
index->ifaces[index->ifaces_num].iface = iface;
index->ifaces[index->ifaces_num].bInterfaceNumber = iface->bInterfaceNumber;
index->ifaces[index->ifaces_num].bAlternateSetting = iface->bAlternateSetting;
index->ifaces[index->ifaces_num].bInterfaceClass = iface->bInterfaceClass;
index->ifaces_num++;
}
if (desc_type == USB_DT_ENDPOINT && index->ifaces_num > 0) {
struct usb_iface_index* iface = &index->ifaces[index->ifaces_num - 1];
if (iface->eps_num < USB_MAX_EP_NUM) {
memcpy(&iface->eps[iface->eps_num].desc, buffer + offset, sizeof(iface->eps[iface->eps_num].desc));
iface->eps_num++;
}
}
offset += desc_length;
}
return true;
}

static struct usb_device_index* add_usb_index(int fd, const char* dev, size_t dev_len)
{
int i = __atomic_fetch_add(&usb_devices_num, 1, __ATOMIC_RELAXED);
if (i >= USB_MAX_FDS)
return NULL;
if (!parse_usb_descriptor(dev, dev_len, &usb_devices[i].index))
return NULL;
__atomic_store_n(&usb_devices[i].fd, fd, __ATOMIC_RELEASE);
return &usb_devices[i].index;
}

struct vusb_connect_string_descriptor {
uint32_t len;
char* str;
} __attribute__((packed));

struct vusb_connect_descriptors {
uint32_t qual_len;
char* qual;
uint32_t bos_len;
char* bos;
uint32_t strs_len;
struct vusb_connect_string_descriptor strs[0];
} __attribute__((packed));

static const char default_string[] = {
8, USB_DT_STRING,
's', 0, 'y', 0, 'z', 0
};

static const char default_lang_id[] = {
4, USB_DT_STRING,
0x09, 0x04
};

static bool lookup_connect_response_in(int fd, const struct vusb_connect_descriptors* descs,
const struct usb_ctrlrequest* ctrl,
struct usb_qualifier_descriptor* qual,
char** response_data, uint32_t* response_length)
{
struct usb_device_index* index = lookup_usb_index(fd);
uint8_t str_idx;
if (!index)
return false;
switch (ctrl->bRequestType & USB_TYPE_MASK) {
case USB_TYPE_STANDARD:
switch (ctrl->bRequest) {
case USB_REQ_GET_DESCRIPTOR:
switch (ctrl->wValue >> 8) {
case USB_DT_DEVICE:
*response_data = (char*)index->dev;
*response_length = sizeof(*index->dev);
return true;
case USB_DT_CONFIG:
*response_data = (char*)index->config;
*response_length = index->config_length;
return true;
case USB_DT_STRING:
str_idx = (uint8_t)ctrl->wValue;
if (descs && str_idx < descs->strs_len) {
*response_data = descs->strs[str_idx].str;
*response_length = descs->strs[str_idx].len;
return true;
}
if (str_idx == 0) {
*response_data = (char*)&default_lang_id[0];
*response_length = default_lang_id[0];
return true;
}
*response_data = (char*)&default_string[0];
*response_length = default_string[0];
return true;
case USB_DT_BOS:
*response_data = descs->bos;
*response_length = descs->bos_len;
return true;
case USB_DT_DEVICE_QUALIFIER:
if (!descs->qual) {
qual->bLength = sizeof(*qual);
qual->bDescriptorType = USB_DT_DEVICE_QUALIFIER;
qual->bcdUSB = index->dev->bcdUSB;
qual->bDeviceClass = index->dev->bDeviceClass;
qual->bDeviceSubClass = index->dev->bDeviceSubClass;
qual->bDeviceProtocol = index->dev->bDeviceProtocol;
qual->bMaxPacketSize0 = index->dev->bMaxPacketSize0;
qual->bNumConfigurations = index->dev->bNumConfigurations;
qual->bRESERVED = 0;
*response_data = (char*)qual;
*response_length = sizeof(*qual);
return true;
}
*response_data = descs->qual;
*response_length = descs->qual_len;
return true;
default:
break;
}
break;
default:
break;
}
break;
default:
break;
}
return false;
}

typedef bool (*lookup_connect_out_response_t)(int fd, const struct vusb_connect_descriptors* descs,
const struct usb_ctrlrequest* ctrl, bool* done);

static bool lookup_connect_response_out_generic(int fd, const struct vusb_connect_descriptors* descs,
const struct usb_ctrlrequest* ctrl, bool* done)
{
switch (ctrl->bRequestType & USB_TYPE_MASK) {
case USB_TYPE_STANDARD:
switch (ctrl->bRequest) {
case USB_REQ_SET_CONFIGURATION:
*done = true;
return true;
default:
break;
}
break;
}
return false;
}

struct vusb_descriptor {
uint8_t req_type;
uint8_t desc_type;
uint32_t len;
char data[0];
} __attribute__((packed));

struct vusb_descriptors {
uint32_t len;
struct vusb_descriptor* generic;
struct vusb_descriptor* descs[0];
} __attribute__((packed));

struct vusb_response {
uint8_t type;
uint8_t req;
uint32_t len;
char data[0];
} __attribute__((packed));

struct vusb_responses {
uint32_t len;
struct vusb_response* generic;
struct vusb_response* resps[0];
} __attribute__((packed));

static bool lookup_control_response(const struct vusb_descriptors* descs, const struct vusb_responses* resps,
struct usb_ctrlrequest* ctrl, char** response_data, uint32_t* response_length)
{
int descs_num = 0;
int resps_num = 0;
if (descs)
descs_num = (descs->len - offsetof(struct vusb_descriptors, descs)) / sizeof(descs->descs[0]);
if (resps)
resps_num = (resps->len - offsetof(struct vusb_responses, resps)) / sizeof(resps->resps[0]);
uint8_t req = ctrl->bRequest;
uint8_t req_type = ctrl->bRequestType & USB_TYPE_MASK;
uint8_t desc_type = ctrl->wValue >> 8;
if (req == USB_REQ_GET_DESCRIPTOR) {
int i;
for (i = 0; i < descs_num; i++) {
struct vusb_descriptor* desc = descs->descs[i];
if (!desc)
continue;
if (desc->req_type == req_type && desc->desc_type == desc_type) {
*response_length = desc->len;
if (*response_length != 0)
*response_data = &desc->data[0];
else
*response_data = NULL;
return true;
}
}
if (descs && descs->generic) {
*response_data = &descs->generic->data[0];
*response_length = descs->generic->len;
return true;
}
} else {
int i;
for (i = 0; i < resps_num; i++) {
struct vusb_response* resp = resps->resps[i];
if (!resp)
continue;
if (resp->type == req_type && resp->req == req) {
*response_length = resp->len;
if (*response_length != 0)
*response_data = &resp->data[0];
else
*response_data = NULL;
return true;
}
}
if (resps && resps->generic) {
*response_data = &resps->generic->data[0];
*response_length = resps->generic->len;
return true;
}
}
return false;
}

#define UDC_NAME_LENGTH_MAX 128

struct usb_raw_init {
__u8 driver_name[UDC_NAME_LENGTH_MAX];
__u8 device_name[UDC_NAME_LENGTH_MAX];
__u8 speed;
};

enum usb_raw_event_type {
USB_RAW_EVENT_INVALID = 0,
USB_RAW_EVENT_CONNECT = 1,
USB_RAW_EVENT_CONTROL = 2,
};

struct usb_raw_event {
__u32 type;
__u32 length;
__u8 data[0];
};

struct usb_raw_ep_io {
__u16 ep;
__u16 flags;
__u32 length;
__u8 data[0];
};

#define USB_RAW_EPS_NUM_MAX 30
#define USB_RAW_EP_NAME_MAX 16
#define USB_RAW_EP_ADDR_ANY 0xff

struct usb_raw_ep_caps {
__u32 type_control : 1;
__u32 type_iso : 1;
__u32 type_bulk : 1;
__u32 type_int : 1;
__u32 dir_in : 1;
__u32 dir_out : 1;
};

struct usb_raw_ep_limits {
__u16 maxpacket_limit;
__u16 max_streams;
__u32 reserved;
};

struct usb_raw_ep_info {
__u8 name[USB_RAW_EP_NAME_MAX];
__u32 addr;
struct usb_raw_ep_caps caps;
struct usb_raw_ep_limits limits;
};

struct usb_raw_eps_info {
struct usb_raw_ep_info eps[USB_RAW_EPS_NUM_MAX];
};

#define USB_RAW_IOCTL_INIT _IOW('U', 0, struct usb_raw_init)
#define USB_RAW_IOCTL_RUN _IO('U', 1)
#define USB_RAW_IOCTL_EVENT_FETCH _IOR('U', 2, struct usb_raw_event)
#define USB_RAW_IOCTL_EP0_WRITE _IOW('U', 3, struct usb_raw_ep_io)
#define USB_RAW_IOCTL_EP0_READ _IOWR('U', 4, struct usb_raw_ep_io)
#define USB_RAW_IOCTL_EP_ENABLE _IOW('U', 5, struct usb_endpoint_descriptor)
#define USB_RAW_IOCTL_EP_DISABLE _IOW('U', 6, __u32)
#define USB_RAW_IOCTL_EP_WRITE _IOW('U', 7, struct usb_raw_ep_io)
#define USB_RAW_IOCTL_EP_READ _IOWR('U', 8, struct usb_raw_ep_io)
#define USB_RAW_IOCTL_CONFIGURE _IO('U', 9)
#define USB_RAW_IOCTL_VBUS_DRAW _IOW('U', 10, __u32)
#define USB_RAW_IOCTL_EPS_INFO _IOR('U', 11, struct usb_raw_eps_info)
#define USB_RAW_IOCTL_EP0_STALL _IO('U', 12)
#define USB_RAW_IOCTL_EP_SET_HALT _IOW('U', 13, __u32)
#define USB_RAW_IOCTL_EP_CLEAR_HALT _IOW('U', 14, __u32)
#define USB_RAW_IOCTL_EP_SET_WEDGE _IOW('U', 15, __u32)

static int usb_raw_open()
{
return open("/dev/raw-gadget", O_RDWR);
}

static int usb_raw_init(int fd, uint32_t speed, const char* driver, const char* device)
{
struct usb_raw_init arg;
strncpy((char*)&arg.driver_name[0], driver, sizeof(arg.driver_name));
strncpy((char*)&arg.device_name[0], device, sizeof(arg.device_name));
arg.speed = speed;
return ioctl(fd, USB_RAW_IOCTL_INIT, &arg);
}

static int usb_raw_run(int fd)
{
return ioctl(fd, USB_RAW_IOCTL_RUN, 0);
}

static int usb_raw_configure(int fd)
{
return ioctl(fd, USB_RAW_IOCTL_CONFIGURE, 0);
}

static int usb_raw_vbus_draw(int fd, uint32_t power)
{
return ioctl(fd, USB_RAW_IOCTL_VBUS_DRAW, power);
}

static int usb_raw_ep0_write(int fd, struct usb_raw_ep_io* io)
{
return ioctl(fd, USB_RAW_IOCTL_EP0_WRITE, io);
}

static int usb_raw_ep0_read(int fd, struct usb_raw_ep_io* io)
{
return ioctl(fd, USB_RAW_IOCTL_EP0_READ, io);
}

static int usb_raw_event_fetch(int fd, struct usb_raw_event* event)
{
return ioctl(fd, USB_RAW_IOCTL_EVENT_FETCH, event);
}

static int usb_raw_ep_enable(int fd, struct usb_endpoint_descriptor* desc)
{
return ioctl(fd, USB_RAW_IOCTL_EP_ENABLE, desc);
}

static int usb_raw_ep_disable(int fd, int ep)
{
return ioctl(fd, USB_RAW_IOCTL_EP_DISABLE, ep);
}

static int usb_raw_ep0_stall(int fd)
{
return ioctl(fd, USB_RAW_IOCTL_EP0_STALL, 0);
}

static int lookup_interface(int fd, uint8_t bInterfaceNumber, uint8_t bAlternateSetting)
{
struct usb_device_index* index = lookup_usb_index(fd);
if (!index)
return -1;
for (int i = 0; i < index->ifaces_num; i++) {
if (index->ifaces[i].bInterfaceNumber == bInterfaceNumber &&
index->ifaces[i].bAlternateSetting == bAlternateSetting)
return i;
}
return -1;
}

#define USB_MAX_PACKET_SIZE 4096

struct usb_raw_control_event {
struct usb_raw_event inner;
struct usb_ctrlrequest ctrl;
char data[USB_MAX_PACKET_SIZE];
};

struct usb_raw_ep_io_data {
struct usb_raw_ep_io inner;
char data[USB_MAX_PACKET_SIZE];
};

static void set_interface(int fd, int n)
{
struct usb_device_index* index = lookup_usb_index(fd);
if (!index)
return;
if (index->iface_cur >= 0 && index->iface_cur < index->ifaces_num) {
for (int ep = 0; ep < index->ifaces[index->iface_cur].eps_num; ep++) {
int rv = usb_raw_ep_disable(fd, index->ifaces[index->iface_cur].eps[ep].handle);
if (rv < 0) {
} else {
}
}
}
if (n >= 0 && n < index->ifaces_num) {
for (int ep = 0; ep < index->ifaces[n].eps_num; ep++) {
int rv = usb_raw_ep_enable(fd, &index->ifaces[n].eps[ep].desc);
if (rv < 0) {
} else {
index->ifaces[n].eps[ep].handle = rv;
}
}
index->iface_cur = n;
}
}

static int configure_device(int fd)
{
struct usb_device_index* index = lookup_usb_index(fd);
if (!index)
return -1;
int rv = usb_raw_vbus_draw(fd, index->bMaxPower);
if (rv < 0) {
return rv;
}
rv = usb_raw_configure(fd);
if (rv < 0) {
return rv;
}
set_interface(fd, 0);
return 0;
}

static volatile long syz_usb_connect_impl(uint64_t speed, uint64_t dev_len, const char* dev,
const struct vusb_connect_descriptors* descs,
lookup_connect_out_response_t lookup_connect_response_out)
{
if (!dev) {
return -1;
}
int fd = usb_raw_open();
if (fd < 0) {
return fd;
}
if (fd >= MAX_FDS) {
close(fd);
return -1;
}
struct usb_device_index* index = add_usb_index(fd, dev, dev_len);
if (!index) {
return -1;
}
char device[32];
sprintf(&device[0], "dummy_udc.%llu", procid);
int rv = usb_raw_init(fd, speed, "dummy_udc", &device[0]);
if (rv < 0) {
return rv;
}
rv = usb_raw_run(fd);
if (rv < 0) {
return rv;
}
bool done = false;
while (!done) {
struct usb_raw_control_event event;
event.inner.type = 0;
event.inner.length = sizeof(event.ctrl);
rv = usb_raw_event_fetch(fd, (struct usb_raw_event*)&event);
if (rv < 0) {
return rv;
}
if (event.inner.type != USB_RAW_EVENT_CONTROL)
continue;
char* response_data = NULL;
uint32_t response_length = 0;
struct usb_qualifier_descriptor qual;
if (event.ctrl.bRequestType & USB_DIR_IN) {
if (!lookup_connect_response_in(fd, descs, &event.ctrl, &qual, &response_data, &response_length)) {
usb_raw_ep0_stall(fd);
continue;
}
} else {
if (!lookup_connect_response_out(fd, descs, &event.ctrl, &done)) {
usb_raw_ep0_stall(fd);
continue;
}
response_data = NULL;
response_length = event.ctrl.wLength;
}
if ((event.ctrl.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD &&
event.ctrl.bRequest == USB_REQ_SET_CONFIGURATION) {
rv = configure_device(fd);
if (rv < 0) {
return rv;
}
}
struct usb_raw_ep_io_data response;
response.inner.ep = 0;
response.inner.flags = 0;
if (response_length > sizeof(response.data))
response_length = 0;
if (event.ctrl.wLength < response_length)
response_length = event.ctrl.wLength;
response.inner.length = response_length;
if (response_data)
memcpy(&response.data[0], response_data, response_length);
else
memset(&response.data[0], 0, response_length);
if (event.ctrl.bRequestType & USB_DIR_IN) {
rv = usb_raw_ep0_write(fd, (struct usb_raw_ep_io*)&response);
} else {
rv = usb_raw_ep0_read(fd, (struct usb_raw_ep_io*)&response);
}
if (rv < 0) {
return rv;
}
}
sleep_ms(200);
return fd;
}

static volatile long syz_usb_connect(volatile long a0, volatile long a1, volatile long a2, volatile long a3)
{
uint64_t speed = a0;
uint64_t dev_len = a1;
const char* dev = (const char*)a2;
const struct vusb_connect_descriptors* descs = (const struct vusb_connect_descriptors*)a3;
return syz_usb_connect_impl(speed, dev_len, dev, descs, &lookup_connect_response_out_generic);
}

static volatile long syz_usb_control_io(volatile long a0, volatile long a1, volatile long a2)
{
int fd = a0;
const struct vusb_descriptors* descs = (const struct vusb_descriptors*)a1;
const struct vusb_responses* resps = (const struct vusb_responses*)a2;
struct usb_raw_control_event event;
event.inner.type = 0;
event.inner.length = USB_MAX_PACKET_SIZE;
int rv = usb_raw_event_fetch(fd, (struct usb_raw_event*)&event);
if (rv < 0) {
return rv;
}
if (event.inner.type != USB_RAW_EVENT_CONTROL) {
return -1;
}
char* response_data = NULL;
uint32_t response_length = 0;
if ((event.ctrl.bRequestType & USB_DIR_IN) && event.ctrl.wLength) {
if (!lookup_control_response(descs, resps, &event.ctrl, &response_data, &response_length)) {
usb_raw_ep0_stall(fd);
return -1;
}
} else {
if ((event.ctrl.bRequestType & USB_TYPE_MASK) == USB_TYPE_STANDARD ||
event.ctrl.bRequest == USB_REQ_SET_INTERFACE) {
int iface_num = event.ctrl.wIndex;
int alt_set = event.ctrl.wValue;
int iface_index = lookup_interface(fd, iface_num, alt_set);
if (iface_index < 0) {
} else {
set_interface(fd, iface_index);
}
}
response_length = event.ctrl.wLength;
}
struct usb_raw_ep_io_data response;
response.inner.ep = 0;
response.inner.flags = 0;
if (response_length > sizeof(response.data))
response_length = 0;
if (event.ctrl.wLength < response_length)
response_length = event.ctrl.wLength;
if ((event.ctrl.bRequestType & USB_DIR_IN) && !event.ctrl.wLength) {
response_length = USB_MAX_PACKET_SIZE;
}
response.inner.length = response_length;
if (response_data)
memcpy(&response.data[0], response_data, response_length);
else
memset(&response.data[0], 0, response_length);
if ((event.ctrl.bRequestType & USB_DIR_IN) && event.ctrl.wLength) {
rv = usb_raw_ep0_write(fd, (struct usb_raw_ep_io*)&response);
} else {
rv = usb_raw_ep0_read(fd, (struct usb_raw_ep_io*)&response);
}
if (rv < 0) {
return rv;
}
sleep_ms(200);
return 0;
}

uint64_t r[1] = {0xffffffffffffffff};

int main(void)
{
syscall(__NR_mmap, /*addr=*/0x1ffff000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul);
syscall(__NR_mmap, /*addr=*/0x20000000ul, /*len=*/0x1000000ul, /*prot=*/7ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul);
syscall(__NR_mmap, /*addr=*/0x21000000ul, /*len=*/0x1000ul, /*prot=*/0ul, /*flags=*/0x32ul, /*fd=*/-1, /*offset=*/0ul);
intptr_t res = 0;
memcpy((void*)0x20000040, "\x12\x01\x00\x00\x6f\xf9\x46\x10\xb4\x07\x0a\x01\x02\x01\x00\x00\x00\x01\x09\x02\x24\x00\x01\x00\x00\x00\x01\x09\x04\xc0\x00\x02\xa6\xdb\x5d\x00\x09\x05\x09\x1e\x00\x00\x00\x00\x00\x09\x05\x8f\x02\x38\xea\x72\xb9\x58\x10\xc9\x67\x92\xa9\xf2\xb6\xce\x7a\xe8\x29\x42\xc1\xea\x33\xc5\xd6\xe1\xfc\xe2\xbe\x25\x87\xb9\x5a\xd0\x14\xd6\xe9\x1f\x33\x12\x98\xf4\x82\x23\x08\x1b\xff\xe7\x21\x16\x72\xd9\xe3\x95\x5c\xd2\x3b\xfb\x1d\xb8\x81\xa7\x64\x2a\xdc\xfa\xa2\xf6\xe8\xcb\x5a\x1c\xbb\x82\x5a\xa1\xcd\x52\xd1\x79\xe3\xa3\x07\xee\x86\xab\x79\x38\x18\x6f\x8e\x83\x98\x07", 140);
res = -1;
res = syz_usb_connect(/*speed=*/0, /*dev_len=*/0x1cf, /*dev=*/0x20000040, /*conn_descs=*/0);
if (res != -1)
r[0] = res;
*(uint32_t*)0x20000240 = 0x2c;
*(uint64_t*)0x20000244 = 0;
*(uint64_t*)0x2000024c = 0;
*(uint64_t*)0x20000254 = 0;
*(uint64_t*)0x2000025c = 0x200001c0;
*(uint8_t*)0x200001c0 = 0x20;
*(uint8_t*)0x200001c1 = 0x29;
*(uint32_t*)0x200001c2 = 0xf;
*(uint8_t*)0x200001c6 = 0xf;
*(uint8_t*)0x200001c7 = 0x29;
*(uint8_t*)0x200001c8 = 3;
*(uint16_t*)0x200001c9 = 0x10;
*(uint8_t*)0x200001cb = 6;
*(uint8_t*)0x200001cc = 0xab;
memcpy((void*)0x200001cd, "\xc6\x7b\x0a\x5d", 4);
memcpy((void*)0x200001d1, "\x96\x24\x22\x38", 4);
*(uint64_t*)0x20000264 = 0;
*(uint32_t*)0x200006c0 = 0x84;
*(uint64_t*)0x200006c4 = 0x20000280;
*(uint8_t*)0x20000280 = 0;
*(uint8_t*)0x20000281 = 8;
*(uint32_t*)0x20000282 = 0x50;
memcpy((void*)0x20000286, "\x36\x27\xfb\xe8\x3b\xd7\x3e\xed\x75\x33\xa9\x6e\x06\xff\x4a\x59\x5e\x69\x91\x55\x3d\xc9\x2a\xd9\x5f\x3a\x7c\x8a\x2d\x96\xd3\x16\x2d\xc7\x3f\x78\xed\xce\x48\xb5\x21\x1b\xf5\x4d\xf6\x05\xa7\x47\x88\x01\x32\x47\x4f\x4f\x9b\x5b\x55\x18\xc1\x6f\xa0\x87\x16\xf4\xb0\x60\x95\x50\x89\x10\xc0\x3b\x62\x99\xb5\x6d\x93\xba\x16\xd2", 80);
*(uint64_t*)0x200006cc = 0;
*(uint64_t*)0x200006d4 = 0x20000340;
*(uint8_t*)0x20000340 = 0;
*(uint8_t*)0x20000341 = 8;
*(uint32_t*)0x20000342 = 1;
*(uint8_t*)0x20000346 = 0x5f;
*(uint64_t*)0x200006dc = 0;
*(uint64_t*)0x200006e4 = 0;
*(uint64_t*)0x200006ec = 0;
*(uint64_t*)0x200006f4 = 0;
*(uint64_t*)0x200006fc = 0;
*(uint64_t*)0x20000704 = 0;
*(uint64_t*)0x2000070c = 0;
*(uint64_t*)0x20000714 = 0;
*(uint64_t*)0x2000071c = 0x20000580;
*(uint8_t*)0x20000580 = 0x40;
*(uint8_t*)0x20000581 = 0x19;
*(uint32_t*)0x20000582 = 2;
memcpy((void*)0x20000586, "J&", 2);
*(uint64_t*)0x20000724 = 0;
*(uint64_t*)0x2000072c = 0;
*(uint64_t*)0x20000734 = 0;
*(uint64_t*)0x2000073c = 0;
syz_usb_control_io(/*fd=*/r[0], /*descs=*/0x20000240, /*resps=*/0x200006c0);
{
int i;
for(i = 0; i < 64; i++) {
syz_usb_control_io(/*fd=*/r[0], /*descs=*/0x20000240, /*resps=*/0x200006c0);
}
}
return 0;
}

Attachment: linux-v6.9_usb_config
Description: Binary data