Re: KASAN: use-after-free Read in f_hidg_read

[Greg KH]

On Fri, Sep 23, 2022 at 11:13:39PM +0800, Rondreis wrote:
> Hello,
> 
> When fuzzing the Linux kernel driver v6.0-rc4, the following crash was
> triggered.
> 
> HEAD commit: 7e18e42e4b280c85b76967a9106a13ca61c16179
> git tree: upstream
> 
> kernel config: https://pastebin.com/raw/xtrgsXP3
> C reproducer: https://pastebin.com/raw/NeCr7cX0
> console output: https://pastebin.com/raw/4uH5CL2k
> 
> Basically, in the c reproducer, we use the gadget module to emulate
> attaching a USB device(vendor id: 0x5ac, product id: 0x30a) and
> executing some simple sequence of system calls.
> To reproduce this crash, we utilize a third-party library to emulate
> the attaching process: https://github.com/linux-usb-gadgets/libusbgx.
> Just clone this repository, install it, and compile the c
> reproducer with ``` gcc crash.c -lusbgx -lconfig -o crash ``` will do
> the trick.
> 
> I would appreciate it if you have any idea how to solve this bug.

Please see my response to other recent syzbot-found-issues on this
mailing list in the past few days as to what I would recommend doing
here.

thanks,

greg k-h