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Message-ID: <ef147298-26a5-26e7-67c9-cd2f13ffb81b@linux.alibaba.com>
Date:   Mon, 25 Sep 2023 10:22:31 +0800
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Subject: Re: [PATCH] ocfs2: Annotate struct ocfs2_replay_map with __counted_by
To:     Kees Cook <keescook@chromium.org>, Mark Fasheh <mark@fasheh.com>,
        akpm <akpm@linux-foundation.org>
Cc:     Joel Becker <jlbec@evilplan.org>,
        Nathan Chancellor <nathan@kernel.org>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Tom Rix <trix@redhat.com>, ocfs2-devel@lists.linux.dev,
        llvm@lists.linux.dev, linux-kernel@vger.kernel.org,
        linux-hardening@vger.kernel.org
References: <20230922174925.work.293-kees@kernel.org>
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From:   Joseph Qi <joseph.qi@linux.alibaba.com>
In-Reply-To: <20230922174925.work.293-kees@kernel.org>
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On 9/23/23 1:49 AM, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
> 
> As found with Coccinelle[1], add __counted_by for struct ocfs2_replay_map.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Mark Fasheh <mark@fasheh.com>
> Cc: Joel Becker <jlbec@evilplan.org>
> Cc: Joseph Qi <joseph.qi@linux.alibaba.com>
> Cc: Nathan Chancellor <nathan@kernel.org>
> Cc: Nick Desaulniers <ndesaulniers@google.com>
> Cc: Tom Rix <trix@redhat.com>
> Cc: ocfs2-devel@lists.linux.dev
> Cc: llvm@lists.linux.dev
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
> ---
>  fs/ocfs2/journal.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
> index ce215565d061..604fea3a26ff 100644
> --- a/fs/ocfs2/journal.c
> +++ b/fs/ocfs2/journal.c
> @@ -90,7 +90,7 @@ enum ocfs2_replay_state {
>  struct ocfs2_replay_map {
>  	unsigned int rm_slots;
>  	enum ocfs2_replay_state rm_state;
> -	unsigned char rm_replay_slots[];
> +	unsigned char rm_replay_slots[] __counted_by(rm_slots);
>  };
>  
>  static void ocfs2_replay_map_set_state(struct ocfs2_super *osb, int state)