From: Niklas Cassel <niklas.cassel@wdc.com> stable inclusion from linux-4.19.207 commit 20c1d98ca96be6b2b583806a01899b1a8d88924b -------------------------------- 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> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- block/blk-zoned.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 13002ba56b4f7..d33e89d28dbeb 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -319,9 +319,6 @@ 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 (copy_from_user(&rep, argp, sizeof(struct blk_zone_report))) return -EFAULT; -- 2.25.1