RE: [patch] rapidio: potential null deref in rio_setup_device()

From: Bounine, Alexandre
Date: Mon Aug 29 2011 - 09:52:05 EST


Dan Carpenter <error27@xxxxxxxxx> wrote:

> The "goto cleanup" path can dereference "rswitch" which is NULL here.
>
> Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
> ---
> This is sort of embarrassing, I've patched this function before but
> missed this. Hopefully it's right now.
>
> diff --git a/drivers/rapidio/rio-scan.c b/drivers/rapidio/rio-scan.c
> index 0914f49..882cef9 100644
> --- a/drivers/rapidio/rio-scan.c
> +++ b/drivers/rapidio/rio-scan.c
> @@ -432,7 +432,7 @@ static struct rio_dev __devinit
> *rio_setup_device(struct rio_net *net,
> /* Assign component tag to device */
> if (next_comptag >= 0x10000) {
> pr_err("RIO: Component Tag Counter Overflow\n");
> - goto cleanup;
> + goto out_rdev;
> }
> rio_mport_write_config_32(port, destid, hopcount,
> RIO_COMPONENT_TAG_CSR,
next_comptag);
> @@ -518,7 +518,7 @@ static struct rio_dev __devinit
> *rio_setup_device(struct rio_net *net,
> cleanup:
> if (rio_is_switch(rdev))
> kfree(rswitch->route_table);

Because rswitch is set not-NULL only for switch devices the check below
can make things simpler:
cleanup:
if (rswitch)
kfree(rswitch->route_table);

> -
> +out_rdev:
> kfree(rdev);
> return NULL;
> }
--
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