Re: [PATCH 06/11] brcmfmac: sdio: Fix undefined behavior due to shift overflowing the constant

From: Kalle Valo
Date: Tue Apr 05 2022 - 21:30:46 EST


+ linux-wireless

Borislav Petkov <bp@xxxxxxxxx> writes:

> From: Borislav Petkov <bp@xxxxxxx>
>
> Fix:
>
> drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c: In function ‘brcmf_sdio_drivestrengthinit’:
> drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c:3798:2: error: case label does not reduce to an integer constant
> case SDIOD_DRVSTR_KEY(BRCM_CC_43143_CHIP_ID, 17):
> ^~~~
> drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c:3809:2: error: case label does not reduce to an integer constant
> case SDIOD_DRVSTR_KEY(BRCM_CC_43362_CHIP_ID, 13):
> ^~~~
>
> See https://lore.kernel.org/r/YkwQ6%2BtIH8GQpuct@xxxxxxx for the gory
> details as to why it triggers with older gccs only.
>
> Signed-off-by: Borislav Petkov <bp@xxxxxxx>
> Cc: Arend van Spriel <aspriel@xxxxxxxxx>
> Cc: Franky Lin <franky.lin@xxxxxxxxxxxx>
> Cc: Hante Meuleman <hante.meuleman@xxxxxxxxxxxx>
> Cc: Kalle Valo <kvalo@xxxxxxxxxx>
> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
> Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
> Cc: brcm80211-dev-list.pdl@xxxxxxxxxxxx
> Cc: netdev@xxxxxxxxxxxxxxx
> ---
> drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
> index ba3c159111d3..d78ccc223709 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c
> @@ -557,7 +557,7 @@ enum brcmf_sdio_frmtype {
> BRCMF_SDIO_FT_SUB,
> };
>
> -#define SDIOD_DRVSTR_KEY(chip, pmu) (((chip) << 16) | (pmu))
> +#define SDIOD_DRVSTR_KEY(chip, pmu) (((unsigned int)(chip) << 16) | (pmu))

Via which tree is this going? I assume not the wireless tree, so:

Acked-by: Kalle Valo <kvalo@xxxxxxxxxx>

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