| Message ID | 20190703145239.ridwf2jegipnoxfz@gofer.mess.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | media: technisat-usb2: break out of loop at end of buffer | expand |
On Wed, Jul 03, 2019 at 03:52:39PM +0100, Sean Young wrote: > Ensure we do not access the buffer beyond the end if no 0xff byte > is encountered. > > Reported-by: syzbot+eaaaf38a95427be88f4b@syzkaller.appspotmail.com > Signed-off-by: Sean Young <sean@mess.org> Both you and Phong Tran appear to be working on fixing this. At a glance, this patch appears to be more complete in that it makes the code flow more sane too. Reviewed-by: Kees Cook <keescook@chromium.org> -Kees > --- > drivers/media/usb/dvb-usb/technisat-usb2.c | 22 ++++++++++------------ > 1 file changed, 10 insertions(+), 12 deletions(-) > > diff --git a/drivers/media/usb/dvb-usb/technisat-usb2.c b/drivers/media/usb/dvb-usb/technisat-usb2.c > index c659e18b358b..676d233d46d5 100644 > --- a/drivers/media/usb/dvb-usb/technisat-usb2.c > +++ b/drivers/media/usb/dvb-usb/technisat-usb2.c > @@ -608,10 +608,9 @@ static int technisat_usb2_frontend_attach(struct dvb_usb_adapter *a) > static int technisat_usb2_get_ir(struct dvb_usb_device *d) > { > struct technisat_usb2_state *state = d->priv; > - u8 *buf = state->buf; > - u8 *b; > - int ret; > struct ir_raw_event ev; > + u8 *buf = state->buf; > + int i, ret; > > buf[0] = GET_IR_DATA_VENDOR_REQUEST; > buf[1] = 0x08; > @@ -647,26 +646,25 @@ static int technisat_usb2_get_ir(struct dvb_usb_device *d) > return 0; /* no key pressed */ > > /* decoding */ > - b = buf+1; > > #if 0 > deb_rc("RC: %d ", ret); > - debug_dump(b, ret, deb_rc); > + debug_dump(buf + 1, ret, deb_rc); > #endif > > ev.pulse = 0; > - while (1) { > - ev.pulse = !ev.pulse; > - ev.duration = (*b * FIRMWARE_CLOCK_DIVISOR * FIRMWARE_CLOCK_TICK) / 1000; > - ir_raw_event_store(d->rc_dev, &ev); > - > - b++; > - if (*b == 0xff) { > + for (i = 1; i < ARRAY_SIZE(state->buf); i++) { > + if (buf[i] == 0xff) { > ev.pulse = 0; > ev.duration = 888888*2; > ir_raw_event_store(d->rc_dev, &ev); > break; > } > + > + ev.pulse = !ev.pulse; > + ev.duration = (buf[i] * FIRMWARE_CLOCK_DIVISOR * > + FIRMWARE_CLOCK_TICK) / 1000; > + ir_raw_event_store(d->rc_dev, &ev); > } > > ir_raw_event_handle(d->rc_dev); > -- > 2.21.0 >
diff --git a/drivers/media/usb/dvb-usb/technisat-usb2.c b/drivers/media/usb/dvb-usb/technisat-usb2.c index c659e18b358b..676d233d46d5 100644 --- a/drivers/media/usb/dvb-usb/technisat-usb2.c +++ b/drivers/media/usb/dvb-usb/technisat-usb2.c @@ -608,10 +608,9 @@ static int technisat_usb2_frontend_attach(struct dvb_usb_adapter *a) static int technisat_usb2_get_ir(struct dvb_usb_device *d) { struct technisat_usb2_state *state = d->priv; - u8 *buf = state->buf; - u8 *b; - int ret; struct ir_raw_event ev; + u8 *buf = state->buf; + int i, ret; buf[0] = GET_IR_DATA_VENDOR_REQUEST; buf[1] = 0x08; @@ -647,26 +646,25 @@ static int technisat_usb2_get_ir(struct dvb_usb_device *d) return 0; /* no key pressed */ /* decoding */ - b = buf+1; #if 0 deb_rc("RC: %d ", ret); - debug_dump(b, ret, deb_rc); + debug_dump(buf + 1, ret, deb_rc); #endif ev.pulse = 0; - while (1) { - ev.pulse = !ev.pulse; - ev.duration = (*b * FIRMWARE_CLOCK_DIVISOR * FIRMWARE_CLOCK_TICK) / 1000; - ir_raw_event_store(d->rc_dev, &ev); - - b++; - if (*b == 0xff) { + for (i = 1; i < ARRAY_SIZE(state->buf); i++) { + if (buf[i] == 0xff) { ev.pulse = 0; ev.duration = 888888*2; ir_raw_event_store(d->rc_dev, &ev); break; } + + ev.pulse = !ev.pulse; + ev.duration = (buf[i] * FIRMWARE_CLOCK_DIVISOR * + FIRMWARE_CLOCK_TICK) / 1000; + ir_raw_event_store(d->rc_dev, &ev); } ir_raw_event_handle(d->rc_dev);
Ensure we do not access the buffer beyond the end if no 0xff byte is encountered. Reported-by: syzbot+eaaaf38a95427be88f4b@syzkaller.appspotmail.com Signed-off-by: Sean Young <sean@mess.org> --- drivers/media/usb/dvb-usb/technisat-usb2.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-)