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From: "Arnd Bergmann" <arnd@arndb.de>
To: "Jiasheng Jiang" <jiasheng@iscas.ac.cn>,
	"Oded Gabbay" <ogabbay@kernel.org>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	ttayar@habana.ai, dliberman@habana.ai, obitton@habana.ai,
	osharabi@habana.ai, dhirschfeld@habana.ai
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH] habanalabs: Fix freeing uninitialized pointers
Date: Wed, 08 Feb 2023 08:21:58 +0100	[thread overview]
Message-ID: <ce2301d2-2bdc-423a-9501-bc45951bb52a@app.fastmail.com> (raw)
In-Reply-To: <20230208070559.19589-1-jiasheng@iscas.ac.cn>

On Wed, Feb 8, 2023, at 08:05, Jiasheng Jiang wrote:
> As the memory allocated by kcalloc has not been set to zero, it may
> contain uninitialized pointers.
> Therefore, free the non-NULL pointers may cause undefined behaviour.
>
> Fixes: 5574cb2194b1 ("habanalabs: Assign each CQ with its own work queue")
> Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>

Did you run into a bug here or find that by inspection?

kcalloc() is definitely meant to return zeroed memory, so I don't see
a bug here:


static inline __alloc_size(1, 2) void *kcalloc(size_t n, size_t size, gfp_t flags)
{
        return kmalloc_array(n, size, flags | __GFP_ZERO);
}


       Arnd

      reply	other threads:[~2023-02-08  7:22 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-02-08  7:05 Jiasheng Jiang
2023-02-08  7:21 ` Arnd Bergmann [this message]

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