| Message ID | 20210730213829.2909-1-paskripkin@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | media: mxl111sf: change mutex_init() location | expand |
On Sat, Jul 31, 2021 at 12:38:29AM +0300, Pavel Skripkin wrote: > 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. What about the other frontends like mxl111sf_frontend_attach_dvbt? They no longer initialize the mutex. Thanks Sean > > 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
On 8/15/21 11:37 AM, Sean Young wrote: > On Sat, Jul 31, 2021 at 12:38:29AM +0300, Pavel Skripkin wrote: >> 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. > > What about the other frontends like mxl111sf_frontend_attach_dvbt? They > no longer initialize the mutex. > Good point. I see, that all other frontends also call mxl111sf_ctrl_msg() inside ->frontend_attach() call. I think, that fixing dvb-usb core is not good idea, so, I will add mutex_init() call inside all frontends, which use mxl111sf_init(). What do you think about it? With regards, Pavel Skripkin
On 8/15/21 11:49 AM, Pavel Skripkin wrote: > On 8/15/21 11:37 AM, Sean Young wrote: >> On Sat, Jul 31, 2021 at 12:38:29AM +0300, Pavel Skripkin wrote: >>> 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. >> >> What about the other frontends like mxl111sf_frontend_attach_dvbt? They >> no longer initialize the mutex. >> > Good point. I see, that all other frontends also call > mxl111sf_ctrl_msg() inside ->frontend_attach() call. > > I think, that fixing dvb-usb core is not good idea, so, I will add > mutex_init() call inside all frontends, which use mxl111sf_init(). > > What do you think about it? > > Something like this should work. Helper is just to not copy-paste code parts. Build tested against v5.14-rc5 diff --git a/drivers/media/usb/dvb-usb-v2/mxl111sf.c b/drivers/media/usb/dvb-usb-v2/mxl111sf.c index 7865fa0a8295..db1ad3815cd5 100644 --- a/drivers/media/usb/dvb-usb-v2/mxl111sf.c +++ b/drivers/media/usb/dvb-usb-v2/mxl111sf.c @@ -49,6 +49,13 @@ MODULE_PARM_DESC(rfswitch, "force rf switch position (0=auto, 1=ext, 2=int)."); DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr); +static inline void mxl111sf_init_msg_mutex(struct dvb_usb_adapter *adap) +{ + struct mxl111sf_state *state = d_to_priv(adap_to_d(adap)); + + mutex_init(&state->msg_lock); +} + int mxl111sf_ctrl_msg(struct mxl111sf_state *state, u8 cmd, u8 *wbuf, int wlen, u8 *rbuf, int rlen) { @@ -931,8 +938,6 @@ 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"); @@ -963,16 +968,19 @@ static int mxl111sf_init(struct dvb_usb_device *d) static int mxl111sf_frontend_attach_dvbt(struct dvb_usb_adapter *adap) { + mxl111sf_init_msg_mutex(adap); return mxl111sf_attach_demod(adap, 0); } static int mxl111sf_frontend_attach_atsc(struct dvb_usb_adapter *adap) { + mxl111sf_init_msg_mutex(adap); return mxl111sf_lgdt3305_frontend_attach(adap, 0); } static int mxl111sf_frontend_attach_mh(struct dvb_usb_adapter *adap) { + mxl111sf_init_msg_mutex(adap); return mxl111sf_lg2160_frontend_attach(adap, 0); } @@ -981,6 +989,7 @@ static int mxl111sf_frontend_attach_atsc_mh(struct dvb_usb_adapter *adap) int ret; pr_debug("%s\n", __func__); + mxl111sf_init_msg_mutex(adap); ret = mxl111sf_lgdt3305_frontend_attach(adap, 0); if (ret < 0) return ret; @@ -1001,6 +1010,7 @@ static int mxl111sf_frontend_attach_mercury(struct dvb_usb_adapter *adap) int ret; pr_debug("%s\n", __func__); + mxl111sf_init_msg_mutex(adap); ret = mxl111sf_lgdt3305_frontend_attach(adap, 0); if (ret < 0) return ret; @@ -1021,6 +1031,7 @@ static int mxl111sf_frontend_attach_mercury_mh(struct dvb_usb_adapter *adap) int ret; pr_debug("%s\n", __func__); + mxl111sf_init_msg_mutex(adap); ret = mxl111sf_attach_demod(adap, 0); if (ret < 0) return ret; With regards, Pavel Skripkin
On Sun, Aug 15, 2021 at 12:06:16PM +0300, Pavel Skripkin wrote: > On 8/15/21 11:49 AM, Pavel Skripkin wrote: > > On 8/15/21 11:37 AM, Sean Young wrote: > > > On Sat, Jul 31, 2021 at 12:38:29AM +0300, Pavel Skripkin wrote: > > > > 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. > > > > > > What about the other frontends like mxl111sf_frontend_attach_dvbt? They > > > no longer initialize the mutex. > > > > > Good point. I see, that all other frontends also call > > mxl111sf_ctrl_msg() inside ->frontend_attach() call. > > > > I think, that fixing dvb-usb core is not good idea, so, I will add > > mutex_init() call inside all frontends, which use mxl111sf_init(). > > > > What do you think about it? > > > > > > > Something like this should work. Helper is just to not copy-paste code > parts. Build tested against v5.14-rc5 How about creating a dvb_usb_device_properties probe function and initializing the mutex init there? Sean > > > diff --git a/drivers/media/usb/dvb-usb-v2/mxl111sf.c > b/drivers/media/usb/dvb-usb-v2/mxl111sf.c > index 7865fa0a8295..db1ad3815cd5 100644 > --- a/drivers/media/usb/dvb-usb-v2/mxl111sf.c > +++ b/drivers/media/usb/dvb-usb-v2/mxl111sf.c > @@ -49,6 +49,13 @@ MODULE_PARM_DESC(rfswitch, "force rf switch position > (0=auto, 1=ext, 2=int)."); > > DVB_DEFINE_MOD_OPT_ADAPTER_NR(adapter_nr); > > +static inline void mxl111sf_init_msg_mutex(struct dvb_usb_adapter *adap) > +{ > + struct mxl111sf_state *state = d_to_priv(adap_to_d(adap)); > + > + mutex_init(&state->msg_lock); > +} > + > int mxl111sf_ctrl_msg(struct mxl111sf_state *state, > u8 cmd, u8 *wbuf, int wlen, u8 *rbuf, int rlen) > { > @@ -931,8 +938,6 @@ 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"); > @@ -963,16 +968,19 @@ static int mxl111sf_init(struct dvb_usb_device *d) > > static int mxl111sf_frontend_attach_dvbt(struct dvb_usb_adapter *adap) > { > + mxl111sf_init_msg_mutex(adap); > return mxl111sf_attach_demod(adap, 0); > } > > static int mxl111sf_frontend_attach_atsc(struct dvb_usb_adapter *adap) > { > + mxl111sf_init_msg_mutex(adap); > return mxl111sf_lgdt3305_frontend_attach(adap, 0); > } > > static int mxl111sf_frontend_attach_mh(struct dvb_usb_adapter *adap) > { > + mxl111sf_init_msg_mutex(adap); > return mxl111sf_lg2160_frontend_attach(adap, 0); > } > > @@ -981,6 +989,7 @@ static int mxl111sf_frontend_attach_atsc_mh(struct > dvb_usb_adapter *adap) > int ret; > pr_debug("%s\n", __func__); > > + mxl111sf_init_msg_mutex(adap); > ret = mxl111sf_lgdt3305_frontend_attach(adap, 0); > if (ret < 0) > return ret; > @@ -1001,6 +1010,7 @@ static int mxl111sf_frontend_attach_mercury(struct > dvb_usb_adapter *adap) > int ret; > pr_debug("%s\n", __func__); > > + mxl111sf_init_msg_mutex(adap); > ret = mxl111sf_lgdt3305_frontend_attach(adap, 0); > if (ret < 0) > return ret; > @@ -1021,6 +1031,7 @@ static int mxl111sf_frontend_attach_mercury_mh(struct > dvb_usb_adapter *adap) > int ret; > pr_debug("%s\n", __func__); > > + mxl111sf_init_msg_mutex(adap); > ret = mxl111sf_attach_demod(adap, 0); > if (ret < 0) > return ret; > > > > With regards, > Pavel Skripkin
On 8/19/21 12:29 PM, Sean Young wrote: > On Sun, Aug 15, 2021 at 12:06:16PM +0300, Pavel Skripkin wrote: >> On 8/15/21 11:49 AM, Pavel Skripkin wrote: >> > On 8/15/21 11:37 AM, Sean Young wrote: >> > > On Sat, Jul 31, 2021 at 12:38:29AM +0300, Pavel Skripkin wrote: >> > > > 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. >> > > >> > > What about the other frontends like mxl111sf_frontend_attach_dvbt? They >> > > no longer initialize the mutex. >> > > >> > Good point. I see, that all other frontends also call >> > mxl111sf_ctrl_msg() inside ->frontend_attach() call. >> > >> > I think, that fixing dvb-usb core is not good idea, so, I will add >> > mutex_init() call inside all frontends, which use mxl111sf_init(). >> > >> > What do you think about it? >> > >> > >> >> >> Something like this should work. Helper is just to not copy-paste code >> parts. Build tested against v5.14-rc5 > > How about creating a dvb_usb_device_properties probe function and > initializing the mutex init there? > > Sounds reasonable. Will do it in v2, thank you! With regards, Pavel Skripkin
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;
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(-)