3.16.77-rc1 review patch. If anyone has any objections, please let me know.
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From: Sean Young sean@mess.org
commit 0c4df39e504bf925ab666132ac3c98d6cbbe380b upstream.
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 [bwh: Backported to 3.16: technisat_usb2_get_ir() still uses a stack buffer, which is not worth fixing on this branch] Signed-off-by: Ben Hutchings ben@decadent.org.uk --- drivers/media/usb/dvb-usb/technisat-usb2.c | 22 ++++++++++------------ 1 file changed, 10 insertions(+), 12 deletions(-)
--- a/drivers/media/usb/dvb-usb/technisat-usb2.c +++ b/drivers/media/usb/dvb-usb/technisat-usb2.c @@ -591,9 +591,9 @@ static int technisat_usb2_frontend_attac
static int technisat_usb2_get_ir(struct dvb_usb_device *d) { - u8 buf[62], *b; - int ret; struct ir_raw_event ev; + u8 buf[62]; + int i, ret;
buf[0] = GET_IR_DATA_VENDOR_REQUEST; buf[1] = 0x08; @@ -629,26 +629,25 @@ unlock: 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(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);