diff options
| author | Dan Carpenter <dan.carpenter@oracle.com> | 2017-07-19 13:06:41 +0300 |
|---|---|---|
| committer | Moyster <oysterized@gmail.com> | 2017-11-06 15:20:34 +0100 |
| commit | d72966e1a992092d1907c2f8867b404d5afb486c (patch) | |
| tree | 20c6df9dfeb31b039e37979e5df502dff9631498 | |
| parent | 2717afc323e7927cc52abac393b0126c90e38fb3 (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>
Cc: stable@vger.kernel.org # all versions at this point
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -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 f3f0801a0..aa4e36b3a 100644 --- a/drivers/ata/libata-scsi.c +++ b/drivers/ata/libata-scsi.c @@ -2794,10 +2794,12 @@ 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]; } |