On Sun, Jun 20, 2021 at 11:23:17PM +0300, Pavel Skripkin wrote:
> My local syzbot instance hit a memory leak in
> cinergyt2_frontend_attach() [1].
>
> The problem was in non-freed dvb_frontend in case of error.
> If dvb_usb_generic_rw() call fails, an error will be returned from
> cinergyt2_frontend_attach() [1] and num_adapters_initialized of
> dvb_usb_device won't be incremented. That means dvb usb library
> won't take care of freeing allocated frontend.
This issue is already fixed by:
9ad1efee086e0 media: dvd_usb: memory leak in cinergyt2_fe_attach
Thanks for reporting and making a patch though.
Sean
>
> Fail log:
> BUG: memory leak
> unreferenced object 0xffff88801d9c6000 (size 2048):
> comm "kworker/1:3", pid 2960, jiffies 4295150569 (age 17.150s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 54 65 72 72 61 54 65 63 ........TerraTec
> 2f 71 61 6e 75 20 55 53 42 32 2e 30 20 48 69 67 /qanu USB2.0 Hig
> backtrace:
> [<ffffffff85e169f0>] kmalloc include/linux/slab.h:556 [inline]
> [<ffffffff85e169f0>] kzalloc include/linux/slab.h:686 [inline]
> [<ffffffff85e169f0>] cinergyt2_fe_attach+0x40/0x110 drivers/media/usb/dvb-usb/cinergyT2-fe.c:271
> [<ffffffff85e15b31>] cinergyt2_frontend_attach+0x61/0x140 drivers/media/usb/dvb-usb/cinergyT2-core.c:74 [1]
> [<ffffffff85dcd71e>] dvb_usb_adapter_frontend_init+0x35e/0x5b0 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:290
> [<ffffffff88f98e83>] dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:90 [inline]
> [<ffffffff88f98e83>] dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:184 [inline]
>
> Fixes: 986bd1e58b18 ("V4L/DVB (9107): Alternative version of Terratec Cinergy T2
> driver")
> Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx>
> ---
> drivers/media/usb/dvb-usb/cinergyT2-core.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/media/usb/dvb-usb/cinergyT2-core.c b/drivers/media/usb/dvb-usb/cinergyT2-core.c
> index 969a7ec71dff..fb60af097535 100644
> --- a/drivers/media/usb/dvb-usb/cinergyT2-core.c
> +++ b/drivers/media/usb/dvb-usb/cinergyT2-core.c
> @@ -79,6 +79,7 @@ static int cinergyt2_frontend_attach(struct dvb_usb_adapter *adap)
> ret = dvb_usb_generic_rw(d, st->data, 1, st->data, 3, 0);
> if (ret < 0) {
> deb_rc("cinergyt2_power_ctrl() Failed to retrieve sleep state info\n");
> + kfree(adap->fe_adap[0].fe);
> }
> mutex_unlock(&d->data_mutex);
>
> --
> 2.32.0
