From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
To: glider@google.com
Cc: walter-zh.wu@mediatek.com, dvyukov@google.com,
gregkh@linuxfoundation.org, akpm@linux-foundation.org,
matthias.bgg@gmail.com, tglx@linutronix.de, jpoimboe@redhat.com,
kstewart@linuxfoundation.org, linux-mm@kvack.org
Subject: Re: [PATCH] lib/stackdepot: fix global out-of-bounds in stack_slabs
Date: Mon, 3 Feb 2020 20:02:26 +0900 [thread overview]
Message-ID: <f2adce7f-3f2f-60d4-4dea-3b146b9d35f5@I-love.SAKURA.ne.jp> (raw)
In-Reply-To: <20200203102953.17349-1-glider@google.com>
On 2020/02/03 19:29, glider@google.com wrote:
> --- a/lib/stackdepot.c
> +++ b/lib/stackdepot.c
> @@ -84,7 +84,9 @@ static bool init_stack_slab(void **prealloc)
> if (stack_slabs[depot_index] == NULL) {
> stack_slabs[depot_index] = *prealloc;
> } else {
> - stack_slabs[depot_index + 1] = *prealloc;
> + /* If this is the last depot slab, do not touch the next one. */
> + if (depot_index + 1 < STACK_ALLOC_MAX_SLABS)
> + stack_slabs[depot_index + 1] = *prealloc;
What prevents memory leak (caused by "*prealloc = NULL;")
when we hit depot_index + 1 >= STACK_ALLOC_MAX_SLABS condition?
> /*
> * This smp_store_release pairs with smp_load_acquire() from
> * |next_slab_inited| above and in stack_depot_save().
>
next prev parent reply other threads:[~2020-02-03 11:02 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-03 10:29 glider
2020-02-03 11:02 ` Tetsuo Handa [this message]
2020-02-03 11:10 ` Alexander Potapenko
2020-02-18 10:29 glider
2020-02-19 21:37 ` Andrew Morton
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