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Date:   Fri, 29 Sep 2023 08:05:30 +0200
From:   Greg KH <gregkh@linuxfoundation.org>
To:     Edward AD <twuufnxlz@gmail.com>
Cc:     alex@ghiti.fr, alexghiti@rivosinc.com, aou@eecs.berkeley.edu,
        conor@kernel.org, guoren@kernel.org, jirislaby@kernel.org,
        linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org,
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        palmer@dabbelt.com, paul.walmsley@sifive.com,
        syzbot+8d2757d62d403b2d9275@syzkaller.appspotmail.com,
        syzkaller-bugs@googlegroups.com
Subject: Re: [PATCH] riscv: fix out of bounds in walk_stackframe
Message-ID: <2023092907-anybody-irregular-a30e@gregkh>
References: <f74665d1-4d28-01a2-5694-b06fde202d39@ghiti.fr>
 <20230928231239.2144579-2-twuufnxlz@gmail.com>
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On Fri, Sep 29, 2023 at 07:12:40AM +0800, Edward AD wrote:
> Add vmalloc and kernel addresses check to prevent invalid access.
> 
> Closes: https://lore.kernel.org/all/20230926105949.1025995-2-twuufnxlz@gmail.com/
> Fixes: 5d8544e2d007 ("RISC-V: Generic library routines and assembly")
> Reported-and-test-by: syzbot+8d2757d62d403b2d9275@syzkaller.appspotmail.com
> Link: https://lore.kernel.org/all/0000000000000170df0605ccf91a@google.com/T/
> Signed-off-by: Edward AD <twuufnxlz@gmail.com>
> ---
>  arch/riscv/kernel/stacktrace.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c
> index 64a9c093aef9..031a4a35c1d0 100644
> --- a/arch/riscv/kernel/stacktrace.c
> +++ b/arch/riscv/kernel/stacktrace.c
> @@ -54,6 +54,9 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs,
>  			break;
>  		/* Unwind stack frame */
>  		frame = (struct stackframe *)fp - 1;
> +		if ((is_vmalloc_addr(frame) && !pfn_valid(page_to_pfn(vmalloc_to_page(frame)))) || 
> +		     !virt_addr_valid(frame))
> +			break;
>  		sp = fp;
>  		if (regs && (regs->epc == pc) && (frame->fp & 0x7)) {
>  			fp = frame->ra;
> -- 
> 2.25.1
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
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- Your patch contains warnings and/or errors noticed by the
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If you wish to discuss this problem further, or you have questions about
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Greg will reply once he has dug out from the pending patches received
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thanks,

greg k-h's patch email bot