Messages in this thread Patch in this message | | | From | Pavel Skripkin <> | Subject | [PATCH] media: mxl111sf: change mutex_init() location | Date | Sat, 31 Jul 2021 00:38:29 +0300 |
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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_frontend_attach_atsc_mh() calls mxl111sf_ctrl_msg() internally we need to initialize state->msg_lock in it to make lockdep happy.
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> --- drivers/media/usb/dvb-usb-v2/mxl111sf.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/media/usb/dvb-usb-v2/mxl111sf.c b/drivers/media/usb/dvb-usb-v2/mxl111sf.c index 7865fa0a8295..2e5663ffa7ce 100644 --- 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_device *d) .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"); @@ -979,8 +977,12 @@ static int mxl111sf_frontend_attach_mh(struct dvb_usb_adapter *adap) static int mxl111sf_frontend_attach_atsc_mh(struct dvb_usb_adapter *adap) { int ret; + struct mxl111sf_state *state = d_to_priv(adap_to_d(adap)); + pr_debug("%s\n", __func__); + mutex_init(&state->msg_lock); + ret = mxl111sf_lgdt3305_frontend_attach(adap, 0); if (ret < 0) return ret; -- 2.32.0
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