When the shared storage is accessed from containers [1], it's not recommended to grant CAP_SYS_ADMIN to containers for access to Persistent Reservations in risk of container escape. Remove the extra CAP_SYS_ADMIN permission constraint for Persistent Reservations ioctl which shall do no harm [2]. [1] https://lore.kernel.org/linux-block/345a7cdc-e55b-7aaa-43d4-59b3f911ef18@xxxxxxxxxxxxxxxxx/ [2] https://lore.kernel.org/linux-block/ZGxaxnOeadVwb2gR@xxxxxxxxxxxxx/ Signed-off-by: Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx> --- I also noticed that the extra CAP_SYS_ADMIN permission constraint is not added until v4 [*] of original pull request for Persistent Reservation API. [*] https://lore.kernel.org/all/1444911052-9423-1-git-send-email-hch@xxxxxx/ --- block/ioctl.c | 10 ---------- 1 file changed, 10 deletions(-) diff --git a/block/ioctl.c b/block/ioctl.c index 9c5f637ff153..46c9ac43bbf8 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -260,8 +260,6 @@ static int blkdev_pr_register(struct block_device *bdev, const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops; struct pr_registration reg; - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; if (!ops || !ops->pr_register) return -EOPNOTSUPP; if (copy_from_user(®, arg, sizeof(reg))) @@ -278,8 +276,6 @@ static int blkdev_pr_reserve(struct block_device *bdev, const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops; struct pr_reservation rsv; - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; if (!ops || !ops->pr_reserve) return -EOPNOTSUPP; if (copy_from_user(&rsv, arg, sizeof(rsv))) @@ -296,8 +292,6 @@ static int blkdev_pr_release(struct block_device *bdev, const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops; struct pr_reservation rsv; - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; if (!ops || !ops->pr_release) return -EOPNOTSUPP; if (copy_from_user(&rsv, arg, sizeof(rsv))) @@ -314,8 +308,6 @@ static int blkdev_pr_preempt(struct block_device *bdev, const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops; struct pr_preempt p; - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; if (!ops || !ops->pr_preempt) return -EOPNOTSUPP; if (copy_from_user(&p, arg, sizeof(p))) @@ -332,8 +324,6 @@ static int blkdev_pr_clear(struct block_device *bdev, const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops; struct pr_clear c; - if (!capable(CAP_SYS_ADMIN)) - return -EPERM; if (!ops || !ops->pr_clear) return -EOPNOTSUPP; if (copy_from_user(&c, arg, sizeof(c))) -- 2.19.1.6.gb485710b
