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Date:   Sat, 6 Aug 2022 18:12:40 +0300
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Subject: Re: [PATCH] maple_tree: Fix mas_alloc_nodes()
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To:     Liam Howlett <liam.howlett@oracle.com>,
        "maple-tree@lists.infradead.org" <maple-tree@lists.infradead.org>,
        "linux-mm@kvack.org" <linux-mm@kvack.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        Andrew Morton <akpm@linux-foundation.org>
References: <20220802193612.2886170-1-Liam.Howlett@oracle.com>
From:   Dmitry Osipenko <digetx@gmail.com>
In-Reply-To: <20220802193612.2886170-1-Liam.Howlett@oracle.com>
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02.08.2022 22:36, Liam Howlett пишет:
> Use MAPLE_ALLOC_SLOTS, which differs on 32bit.  This was causing an
> out of bounds issue on 32bit bulk allocations
> 
> Fixes: 06b152b7980a (Maple Tree: add new data structure)
> Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
> ---
>  lib/maple_tree.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index 4e41f3394114..032e7bb0d44f 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -1242,7 +1242,7 @@ static inline void mas_alloc_nodes(struct ma_state *mas, gfp_t gfp)
>  
>  	node = mas->alloc;
>  	while (requested) {
> -		max_req = MAPLE_NODE_SLOTS - 1;
> +		max_req = MAPLE_ALLOC_SLOTS;
>  		if (node->slot[0]) {
>  			unsigned int offset = node->node_count + 1;
>  

Hello Liam,

This fixed the bug, thank you!

Tested-by: Dmitry Osipenko <digetx@gmail.com> # ARM32 Tegra