Re: [PATCH] ata: ahci_dwc: reject invalid device tree port numbers

[Damien Le Moal <dlemoal@kernel.org>]

On 11/4/26 23:13, shao.mingyin@zte.com.cn wrote:
> From: Shao Mingyin <shao.mingyin@zte.com.cn>
> 
> ahci_dwc_init_dmacr() reads the "reg" property of every available child
> node and uses it directly as a port number, both to compute the port
> MMIO base and as an index into dpriv->dmacr[], which has AHCI_MAX_PORTS
> entries.  ahci_platform_get_resources(), which runs earlier, checks the
> same property against hpriv->nports and skips invalid child nodes, but
> this second walk does not.
> 
> A device tree that describes one valid port and one port with a "reg"
> value above AHCI_MAX_PORTS therefore makes the driver write past
> dpriv->dmacr[] and access MMIO beyond the mapped region.  Apply the same
> check as the resource loop and skip invalid child nodes with a warning.
> 
> Fixes: 33629d35090f ("ata: ahci: Add DWC AHCI SATA controller support")
> Cc: stable@vger.kernel.org
> Signed-off-by: Shao Mingyin <shao.mingyin@zte.com.cn>

Looks OK.

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

-- 
Damien Le Moal
Western Digital Research