From: Niklas Cassel niklas.cassel@wdc.com

Performing a BLKREPORTZONE operation should be allowed under the same permissions as read(). (read() does not require CAP_SYS_ADMIN).

Remove the CAP_SYS_ADMIN requirement, and instead check that the fd was successfully opened with FMODE_READ. This way BLKREPORTZONE will match the access control requirement of read().

Fixes: 3ed05a987e0f ("blk-zoned: implement ioctls") Signed-off-by: Niklas Cassel niklas.cassel@wdc.com Reviewed-by: Damien Le Moal damien.lemoal@wdc.com Cc: stable@vger.kernel.org # v4.10+ --- Changes since v1: - Pick up tag from Damien. - Add fixes tag and CC stable.

block/blk-zoned.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 0789e6e9f7db..e05fe8dbb06d 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -288,8 +288,8 @@ int blkdev_report_zones_ioctl(struct block_device *bdev, fmode_t mode, if (!blk_queue_is_zoned(q)) return -ENOTTY;

- if (!capable(CAP_SYS_ADMIN)) - return -EACCES; + if (!(mode & FMODE_READ)) + return -EBADF;

if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report))) return -EFAULT;