Re: [PATCH v2] wifi: wilc1000: use vmm_table as array in wilc struct

[Jeff Johnson]

On 10/16/2023 1:29 AM, Alexis Lothoré wrote:
> From: Ajay Singh <ajay.kathat@xxxxxxxxxxxxx>
>
> 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)
>
> Fixes: 40b717bfcefa ("wifi: wilc1000: fix DMA on stack objects")
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Ajay Singh <ajay.kathat@xxxxxxxxxxxxx>
> Signed-off-by: Alexis Lothoré <alexis.lothore@xxxxxxxxxxx>
> ---
> Changes in v2:
> - keep dedicated dynamic allocation for vmm_table
> - Link to v1: https://lore.kernel.org/r/20231013-wilc1000_tx_oops-v1-1-3761beb9524d@xxxxxxxxxxx
> ---
>   drivers/net/wireless/microchip/wilc1000/wlan.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/microchip/wilc1000/wlan.c b/drivers/net/wireless/microchip/wilc1000/wlan.c
> index 58bbf50081e4..e4113f2dfadf 100644
> --- a/drivers/net/wireless/microchip/wilc1000/wlan.c
> +++ b/drivers/net/wireless/microchip/wilc1000/wlan.c
> @@ -1492,7 +1492,7 @@ int wilc_wlan_init(struct net_device *dev)
>   	}
>   
>   	if (!wilc->vmm_table)
> -		wilc->vmm_table = kzalloc(WILC_VMM_TBL_SIZE, GFP_KERNEL);
> +		wilc->vmm_table = kzalloc(WILC_VMM_TBL_SIZE * sizeof(u32), GFP_KERNEL);

this is probably OK since the values are constant, but kcalloc() is 
generally preferred

>   
>   	if (!wilc->vmm_table) {
>   		ret = -ENOBUFS;
>
> ---
> base-commit: ea12d85cbfd6b08fff40a4fefccc011b6cfadf8e
> change-id: 20231012-wilc1000_tx_oops-58ce91ee3e93
>
> Best regards,