Re: [PATCH] mvsas:Fix possible NULL pointer deference in mvs_dev_found_notify
From: Luis de Bethencourt
Date: Sat Jul 02 2016 - 07:33:31 EST
On 01/07/16 18:43, Nicholas Krause wrote:
> This adds properly checking after the call to mvs_find_dev_mvi
> due to this function being able to return a NULL pointer and if
> this does arise we will deference it in mvs_alloc_dev due to
> this function never checking if a NULL pointer is given as
> it's input argument.
> v2 - Fix NULL pointer deferenece in error path by calling
> spin_unlock_irqrestore on the now NULL pointer, as returned
> by mvs_find_dev_mvi.
Hi Nicholas,
You mention v2 here but this is [PATCH] and not [PATCH v2]. Is this
the first version of the patch or second?
>
> Signed-off-by: Nicholas Krause <xerofoify@xxxxxxxxx>
> ---
If the "v2 -" comments are part of the review and not of the git commit
message it is better to place it here. Between the "---" and the diff.
This is because when the maintainer applies the patch this section will
be truncated, and it won't show in the git log.
> drivers/scsi/mvsas/mv_sas.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/scsi/mvsas/mv_sas.c b/drivers/scsi/mvsas/mv_sas.c
> index 83cd3ea..74f3954 100644
> --- a/drivers/scsi/mvsas/mv_sas.c
> +++ b/drivers/scsi/mvsas/mv_sas.c
> @@ -1191,6 +1191,10 @@ int mvs_dev_found_notify(struct domain_device *dev, int lock)
> struct mvs_device *mvi_device;
>
> mvi = mvs_find_dev_mvi(dev);
> + if (!mvi) {
> + res = -1;
> + goto found_null;
> + }
>
> if (lock)
> spin_lock_irqsave(&mvi->lock, flags);
> @@ -1230,6 +1234,7 @@ int mvs_dev_found_notify(struct domain_device *dev, int lock)
> found_out:
> if (lock)
> spin_unlock_irqrestore(&mvi->lock, flags);
> +found_null:
> return res;
> }
>
>
If the goto is just going to return, why not do a return directly instead?
if (!mvi)
return -1;
Thanks for the patch,
Luis