| Message ID | 20210620202317.4338-1-paskripkin@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | media: dvb-usb: fix memory leak in cinergyt2_frontend_attach | expand |
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@gmail.com> > --- > 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
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);
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. 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@gmail.com> --- drivers/media/usb/dvb-usb/cinergyT2-core.c | 1 + 1 file changed, 1 insertion(+)