libata: array underflow in ata_find_dev()
authorDan Carpenter <dan.carpenter@oracle.com>
Wed, 19 Jul 2017 10:06:41 +0000 (13:06 +0300)
committerTejun Heo <tj@kernel.org>
Wed, 19 Jul 2017 14:31:51 +0000 (10:31 -0400)
commit59a5e266c3f5c1567508888dd61a45b86daed0fa
treef65ab2a5a55997eb1376f9234a0d51546a1c6150
parent6ac1d1532c888b030acb3b4ac82425448cb15198
libata: array underflow in ata_find_dev()

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
drivers/ata/libata-scsi.c