Messages in this thread | | | Date | Thu, 13 Apr 2023 14:47:58 +0200 | From | Greg KH <> | Subject | Re: [PATCH] misc: hisi_hikey_usb: Fix use after free bug in hisi_hikey_usb_remove due to race condition |
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On Thu, Apr 13, 2023 at 07:12:07PM +0800, Zheng Hacker wrote: > Yongqin Liu <yongqin.liu@linaro.org> 于2023年4月13日周四 18:55写道: > > > > Hi, Zheng > > > > On Thu, 13 Apr 2023 at 16:08, Zheng Hacker <hackerzheng666@gmail.com> wrote: > > > > > > Friendly ping about the bug. > > > > Sorry, wasn't aware of this message before, > > > > Could you please help share the instructions to reproduce the problem > > this change fixes? > > > > Hi Yongqin, > > Thanks for your reply. This bug is found by static analysis. There is no PoC. > > >From my personal experience, triggering race condition bugs stably in > the kernel needs some tricks. > For example, you can insert some sleep-time code to slow down the > thread until the related object is freed. > Besides, you can use gdb to control the time window. Also, there are > some other tricks as [1] said. > > As for the reproduction, this attack vector requires that the attacker > can physically access the device. > When he/she unplugs the usb, the remove function is triggered, and if > the set callback is invoked, there might be a race condition.
How does the removal of the USB device trigger a platform device removal?
Are you sure this can be triggered by some other way other than manually unloading the driver?
thanks,
greg k-h
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