From: Sean Young sean@mess.org
[ Upstream commit 0c4df39e504bf925ab666132ac3c98d6cbbe380b ]
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 Reviewed-by: Kees Cook keescook@chromium.org Signed-off-by: Mauro Carvalho Chehab mchehab+samsung@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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 18d0f8f5283fa..8d8e9f56a8be5 100644 --- a/drivers/media/usb/dvb-usb/technisat-usb2.c +++ b/drivers/media/usb/dvb-usb/technisat-usb2.c @@ -607,10 +607,9 @@ 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; @@ -646,26 +645,25 @@ 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);