Re: general protection fault in put_page

[Greg KH <gregkh@linuxfoundation.org>]

On Sun, Aug 07, 2022 at 05:50:56PM +0800, Wei Chen wrote:
> Dear Linux Developer,
> 
> Recently when using our tool to fuzz kernel, the following crash was triggered:
> 
> HEAD commit: 31f4f5b495a6 Linux 5.4-rc7
> git tree: upstream
> compiler: clang 12.0.0
> console output:
> https://drive.google.com/file/d/1rjxlk2_QNsl6CcOwElvUSq5Yhcafb6Il/view?usp=sharing
> Syzlang reproducer:
> https://drive.google.com/file/d/1MFN7c56voPBkd7LzgO0mGZ_oOQNHyK-w/view?usp=sharing
> kernel config: https://drive.google.com/file/d/1sFjtE830MyLBJYZzwZ9sJRsKdf5EzUTV/view?usp=sharing
> 
> However, we tried to use syz-prog2c to convert the Syzlang reproducer
> to C format. But the crash wasn't reproduced by the C program. Please
> use syz-execprog to execute the Syzlang reproducer directly on kernel
> to reproduce the bug.
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: Wei Chen <harperchen1110@gmail.com>

As you have a reproducer, please feel free to submit a fix for this,
but:

> 
> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [#1] PREEMPT SMP KASAN
> CPU: 0 PID: 16421 Comm: syz-executor Not tainted 5.4.0-rc7+ #28

Wow that ia a _VERY_ old and obsolete kernel version.  Please try
something more modern, that is not a valid kernel release to be testing
at all.

How does 5.19.0 work for you?

thanks,

greg k-h