[PATCH 4.9 042/240] media: dvb-usb: fix memory leak in dvb_usb_adapter_init

Greg Kroah-Hartman
2021-05-20T11:09:05Z

From: Pavel Skripkin <paskripkin@gmail.com>

[ Upstream commit b7cd0da982e3043f2eec7235ac5530cb18d6af1d ]

syzbot reported memory leak in dvb-usb. The problem was
in invalid error handling in dvb_usb_adapter_init().

for (n = 0; n < d->props.num_adapters; n++) {
....
if ((ret = dvb_usb_adapter_stream_init(adap)) ||
(ret = dvb_usb_adapter_dvb_init(adap, adapter_nrs)) ||
(ret = dvb_usb_adapter_frontend_init(adap))) {
return ret;
}
...
d->num_adapters_initialized++;
...
}

In case of error in dvb_usb_adapter_dvb_init() or
dvb_usb_adapter_dvb_init() d->num_adapters_initialized won't be
incremented, but dvb_usb_adapter_exit() relies on it:

for (n = 0; n < d->num_adapters_initialized; n++)

So, allocated objects won't be freed.

Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Reported-by: syzbot+3c2be7424cea3b932b0e@syzkaller.appspotmail.com
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/media/usb/dvb-usb/dvb-usb-init.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/media/usb/dvb-usb/dvb-usb-init.c b/drivers/media/usb/dvb-usb/dvb-usb-init.c
index b3413404f91a..690c1e06fbfa 100644
--- a/drivers/media/usb/dvb-usb/dvb-usb-init.c
+++ b/drivers/media/usb/dvb-usb/dvb-usb-init.c
@@ -82,11 +82,17 @@ static int dvb_usb_adapter_init(struct dvb_usb_device *d, short *adapter_nrs)
}
}

- if ((ret = dvb_usb_adapter_stream_init(adap)) ||
- (ret = dvb_usb_adapter_dvb_init(adap, adapter_nrs)) ||
- (ret = dvb_usb_adapter_frontend_init(adap))) {
+ ret = dvb_usb_adapter_stream_init(adap);
+ if (ret)
return ret;
- }
+
+ ret = dvb_usb_adapter_dvb_init(adap, adapter_nrs);
+ if (ret)
+ goto dvb_init_err;
+
+ ret = dvb_usb_adapter_frontend_init(adap);
+ if (ret)
+ goto frontend_init_err;

/* use exclusive FE lock if there is multiple shared FEs */
if (adap->fe_adap[1].fe)
@@ -106,6 +112,12 @@ static int dvb_usb_adapter_init(struct dvb_usb_device *d, short *adapter_nrs)
}

return 0;
+
+frontend_init_err:
+ dvb_usb_adapter_dvb_exit(adap);
+dvb_init_err:
+ dvb_usb_adapter_stream_exit(adap);
+ return ret;
}

static int dvb_usb_adapter_exit(struct dvb_usb_device *d)
--
2.30.2