diff options
| author | Dan Carpenter <dan.carpenter@oracle.com> | 2017-07-19 13:06:41 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-08-11 08:33:50 -0700 |
| commit | b1f866f1b7b6c46a1269766dfb6672f454fbc172 (patch) | |
| tree | fa470938c6c1f817acb43bb79151a7facaa90efc /drivers/ata | |
| parent | d4f197159d1029ef723f595a65975cd682605094 (diff) | |
libata: array underflow in ata_find_dev()
commit 59a5e266c3f5c1567508888dd61a45b86daed0fa upstream.
My static checker complains that "devno" can be negative, meaning that
we read before the start of the loop. I've looked at the code, and I
think the warning is right. This come from /proc so it's root only or
it would be quite a quite a serious bug. The call tree looks like this:
proc_scsi_write() <- gets id and channel from simple_strtoul()
-> scsi_add_single_device() <- calls shost->transportt->user_scan()
-> ata_scsi_user_scan()
-> ata_find_dev()
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/ata')
| -rw-r--r-- | drivers/ata/libata-scsi.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c index 49ba9834c715..12d59968020f 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -3028,10 +3028,12 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc) static struct ata_device *ata_find_dev(struct ata_port *ap, int devno) { if (!sata_pmp_attached(ap)) { - if (likely(devno < ata_link_max_devices(&ap->link))) + if (likely(devno >= 0 && + devno < ata_link_max_devices(&ap->link))) return &ap->link.device[devno]; } else { - if (likely(devno < ap->nr_pmp_links)) + if (likely(devno >= 0 && + devno < ap->nr_pmp_links)) return &ap->pmp_link[devno].device[0]; } |