Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 5.10 86/99] media: mxl111sf: change mutex_init() location | Date | Mon, 20 Dec 2021 15:34:59 +0100 |
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From: Pavel Skripkin <paskripkin@gmail.com>
commit 44870a9e7a3c24acbb3f888b2a7cc22c9bdf7e7f upstream.
Syzbot reported, that mxl111sf_ctrl_msg() uses uninitialized mutex. The problem was in wrong mutex_init() location.
Previous mutex_init(&state->msg_lock) call was in ->init() function, but dvb_usbv2_init() has this order of calls:
dvb_usbv2_init() dvb_usbv2_adapter_init() dvb_usbv2_adapter_frontend_init() props->frontend_attach()
props->init()
Since mxl111sf_* devices call mxl111sf_ctrl_msg() in ->frontend_attach() internally we need to initialize state->msg_lock before frontend_attach(). To achieve it, ->probe() call added to all mxl111sf_* devices, which will simply initiaize mutex.
Reported-and-tested-by: syzbot+5ca0bf339f13c4243001@syzkaller.appspotmail.com
Fixes: 8572211842af ("[media] mxl111sf: convert to new DVB USB") Signed-off-by: Pavel Skripkin <paskripkin@gmail.com> Signed-off-by: Sean Young <sean@mess.org> Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/media/usb/dvb-usb-v2/mxl111sf.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-)
--- a/drivers/media/usb/dvb-usb-v2/mxl111sf.c +++ b/drivers/media/usb/dvb-usb-v2/mxl111sf.c @@ -931,8 +931,6 @@ static int mxl111sf_init(struct dvb_usb_ .len = sizeof(eeprom), .buf = eeprom }, }; - mutex_init(&state->msg_lock); - ret = get_chip_info(state); if (mxl_fail(ret)) pr_err("failed to get chip info during probe"); @@ -1074,6 +1072,14 @@ static int mxl111sf_get_stream_config_dv return 0; } +static int mxl111sf_probe(struct dvb_usb_device *dev) +{ + struct mxl111sf_state *state = d_to_priv(dev); + + mutex_init(&state->msg_lock); + return 0; +} + static struct dvb_usb_device_properties mxl111sf_props_dvbt = { .driver_name = KBUILD_MODNAME, .owner = THIS_MODULE, @@ -1083,6 +1089,7 @@ static struct dvb_usb_device_properties .generic_bulk_ctrl_endpoint = 0x02, .generic_bulk_ctrl_endpoint_response = 0x81, + .probe = mxl111sf_probe, .i2c_algo = &mxl111sf_i2c_algo, .frontend_attach = mxl111sf_frontend_attach_dvbt, .tuner_attach = mxl111sf_attach_tuner, @@ -1124,6 +1131,7 @@ static struct dvb_usb_device_properties .generic_bulk_ctrl_endpoint = 0x02, .generic_bulk_ctrl_endpoint_response = 0x81, + .probe = mxl111sf_probe, .i2c_algo = &mxl111sf_i2c_algo, .frontend_attach = mxl111sf_frontend_attach_atsc, .tuner_attach = mxl111sf_attach_tuner, @@ -1165,6 +1173,7 @@ static struct dvb_usb_device_properties .generic_bulk_ctrl_endpoint = 0x02, .generic_bulk_ctrl_endpoint_response = 0x81, + .probe = mxl111sf_probe, .i2c_algo = &mxl111sf_i2c_algo, .frontend_attach = mxl111sf_frontend_attach_mh, .tuner_attach = mxl111sf_attach_tuner, @@ -1233,6 +1242,7 @@ static struct dvb_usb_device_properties .generic_bulk_ctrl_endpoint = 0x02, .generic_bulk_ctrl_endpoint_response = 0x81, + .probe = mxl111sf_probe, .i2c_algo = &mxl111sf_i2c_algo, .frontend_attach = mxl111sf_frontend_attach_atsc_mh, .tuner_attach = mxl111sf_attach_tuner, @@ -1311,6 +1321,7 @@ static struct dvb_usb_device_properties .generic_bulk_ctrl_endpoint = 0x02, .generic_bulk_ctrl_endpoint_response = 0x81, + .probe = mxl111sf_probe, .i2c_algo = &mxl111sf_i2c_algo, .frontend_attach = mxl111sf_frontend_attach_mercury, .tuner_attach = mxl111sf_attach_tuner, @@ -1381,6 +1392,7 @@ static struct dvb_usb_device_properties .generic_bulk_ctrl_endpoint = 0x02, .generic_bulk_ctrl_endpoint_response = 0x81, + .probe = mxl111sf_probe, .i2c_algo = &mxl111sf_i2c_algo, .frontend_attach = mxl111sf_frontend_attach_mercury_mh, .tuner_attach = mxl111sf_attach_tuner,
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