On 02/07/16 20:05, James Bottomley wrote: > On Sat, 2016-07-02 at 19:16 +0100, Luis de Bethencourt wrote: >> On 02/07/16 18:00, 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. Signed-off-by: Nicholas Krause < >>> xerofoify@xxxxxxxxx> >>> --- >>> v3 - Make logic simpler on error path by returning -1 directly >>> if mvs_find_dev_mvi returns NULL. >>> v2 - Fix NULL pointer deferenece in error path by calling >>> spin_unlock_irqrestore on the now NULL pointer, as returned >>> >>> >>> drivers/scsi/mvsas/mv_sas.c | 2 ++ >>> 1 file changed, 2 insertions(+) >>> >>> diff --git a/drivers/scsi/mvsas/mv_sas.c >>> b/drivers/scsi/mvsas/mv_sas.c >>> index 5b9fcff..dffab01 100644 >>> --- a/drivers/scsi/mvsas/mv_sas.c >>> +++ b/drivers/scsi/mvsas/mv_sas.c >>> @@ -1194,6 +1194,8 @@ int mvs_dev_found_notify(struct domain_device >>> *dev, int lock) >>> struct mvs_device *mvi_device; >>> >>> mvi = mvs_find_dev_mvi(dev); >>> + if (!mvi) >>> + return -1; >>> >>> if (lock) >>> spin_lock_irqsave(&mvi->lock, flags); >>> >> >> This looks better :) >> >> Checking the value of mvi makes sense if mvs_find_dev_mvi() can >> return NULL. > > Which it can't, if you actually look at the function. For this to > happen, we'd have to be receiving a discovery event for a non-existent > port on the adapter, meaning the system was so corrupted that operation > shouldn't be continuing. > > Nick is a known bogus patch submitter. If you want to review them, > that's your choice (and perhaps some might be useful), but it's not > unreasonable of me to expect the review will be thorough enough to turn > up issues like this. > > James I had my suspicions about mvfs_find_dev_mvi() returning NULL. Which is why I said "if it can return NULL". Unfortunately I assumed the base of the patch was properly considered, because I didn't knew about Nick. I just searched around and now understand what you mean about his bogus patches. Sorry I wasn't thorough enough on my review, I know the above isn't an excuse. Lesson learned. In a related note, why is mvi initialized to NULL in mvfs_find_dev_mvi() if it is going to be overwritten? Curious. Thanks and apologies, Luis > > >> Reviewed-by: Luis de Bethencourt <luisbg@xxxxxxxxxxxxxxx> >> >> Thanks, >> Luis >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-scsi" >> in >> the body of a message to majordomo@xxxxxxxxxxxxxxx >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> > -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
