From: Niklas Cassel niklas.cassel@wdc.com
commit 4d643b66089591b4769bcdb6fd1bfeff2fe301b8 upstream.
A user space process should not need the CAP_SYS_ADMIN capability set in order to perform a BLKREPORTZONE ioctl.
Getting the zone report is required in order to get the write pointer. Neither read() nor write() requires CAP_SYS_ADMIN, so it is reasonable that a user space process that can read/write from/to the device, also can get the write pointer. (Since e.g. writes have to be at the write pointer.)
Fixes: 3ed05a987e0f ("blk-zoned: implement ioctls") Signed-off-by: Niklas Cassel niklas.cassel@wdc.com Reviewed-by: Damien Le Moal damien.lemoal@wdc.com Reviewed-by: Aravind Ramesh aravind.ramesh@wdc.com Reviewed-by: Adam Manzanares a.manzanares@samsung.com Reviewed-by: Himanshu Madhani himanshu.madhani@oracle.com Reviewed-by: Johannes Thumshirn johannes.thumshirn@wdc.com Cc: stable@vger.kernel.org # v4.10+ Link: https://lore.kernel.org/r/20210811110505.29649-3-Niklas.Cassel@wdc.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- block/blk-zoned.c | 3 --- 1 file changed, 3 deletions(-)
--- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -316,9 +316,6 @@ int blkdev_report_zones_ioctl(struct blo if (!blk_queue_is_zoned(q)) return -ENOTTY;
- if (!capable(CAP_SYS_ADMIN)) - return -EACCES; - if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report))) return -EFAULT;