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Date:   Fri, 13 Oct 2023 11:24:31 +0200
From:   Michael Walle <mwalle@kernel.org>
To:     =?UTF-8?Q?Alexis_Lothor=C3=A9?= <alexis.lothore@bootlin.com>
Cc:     Claudiu Beznea <claudiu.beznea@tuxon.dev>,
        Kalle Valo <kvalo@kernel.org>, linux-wireless@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        Thomas Petazzoni <thomas.petazzoni@bootlin.com>,
        Ajay Singh <ajay.kathat@microchip.com>, stable@vger.kernel.org,
        heiko.thiery@gmail.com
Subject: Re: [PATCH] wifi: wilc1000: use vmm_table as array in wilc struct
In-Reply-To: <20231013-wilc1000_tx_oops-v1-1-3761beb9524d@bootlin.com>
References: <20231013-wilc1000_tx_oops-v1-1-3761beb9524d@bootlin.com>
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Hi,

Am 2023-10-13 10:26, schrieb Alexis Lothoré:
> From: Ajay Singh <ajay.kathat@microchip.com>
> 
> Enabling KASAN and running some iperf tests raises some memory issues 
> with
> vmm_table:
> 
> BUG: KASAN: slab-out-of-bounds in wilc_wlan_handle_txq+0x6ac/0xdb4
> Write of size 4 at addr c3a61540 by task wlan0-tx/95
> 
> KASAN detects that we are writing data beyond range allocated to 
> vmm_table.
> There is indeed a mismatch between the size passed to allocator in
> wilc_wlan_init, and the range of possible indexes used later: 
> allocation
> size is missing a multiplication by sizeof(u32)

Nice catch.

> While at it, instead of simply multiplying the allocation size, do not 
> keep
> dedicated dynamic allocation for vmm_table: define it as an array with 
> the
> relevant size in wilc struct, which is already dynamically allocated
> 
> Fixes: 40b717bfcefa ("wifi: wilc1000: fix DMA on stack objects")
> Cc: stable@vger.kernel.org
> Signed-off-by: Ajay Singh <ajay.kathat@microchip.com>
> Signed-off-by: Alexis Lothoré <alexis.lothore@bootlin.com>

Looks good to me. But you'll change the alignment of the table, not sure
if that matters for some DMA controllers.

-michael