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 for <linuxppc-dev@lists.ozlabs.org>; Mon, 25 Apr 2016 18:46:36 +1000 (AEST)
Date: Mon, 25 Apr 2016 03:46:26 -0500
From: Segher Boessenkool <segher@kernel.crashing.org>
To: Khem Raj <raj.khem@gmail.com>
Cc: linuxppc-dev@lists.ozlabs.org, Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH] powerpc/ptrace: Fix out of bounds array access warning
Message-ID: <20160425084626.GA1672@gate.crashing.org>
References: <1461564006-22331-1-git-send-email-raj.khem@gmail.com>
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On Sun, Apr 24, 2016 at 11:00:06PM -0700, Khem Raj wrote:
> gcc-6 correctly warns about a out of bounds access
> 
> arch/powerpc/kernel/ptrace.c:407:24: warning: index 32 denotes an offset greater than size of 'u64[32][1] {aka long long unsigned int[32][1]}' [-Warray-bounds]
>         offsetof(struct thread_fp_state, fpr[32][0]));
>                         ^
> 
> check the end of array instead of beginning of next element to fix this

This should be fixed by doing

>         offsetof(struct thread_fp_state, fpr[32]));

instead; [31][1] is not the correct offset when TS_FPRWIDTH > 1.


Segher