Messages in this thread | | | Subject | Re: [PATCH] media: mxl111sf: change mutex_init() location | From | Pavel Skripkin <> | Date | Sun, 15 Aug 2021 11:49:26 +0300 |
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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
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