diff options
Diffstat (limited to 'block')
| -rw-r--r-- | block/ioctl.c | 34 |
1 files changed, 23 insertions, 11 deletions
diff --git a/block/ioctl.c b/block/ioctl.c index fd48f82f9f03..0b04661ac809 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -318,7 +318,13 @@ int blkdev_compat_ptr_ioctl(struct block_device *bdev, blk_mode_t mode, EXPORT_SYMBOL(blkdev_compat_ptr_ioctl); #endif -static bool blkdev_pr_allowed(struct block_device *bdev, blk_mode_t mode) +enum pr_direction { + PR_IN, /* read from device */ + PR_OUT, /* write to device */ +}; + +static bool blkdev_pr_allowed(struct block_device *bdev, blk_mode_t mode, + enum pr_direction dir) { /* no sense to make reservations for partitions */ if (bdev_is_partition(bdev)) @@ -326,11 +332,17 @@ static bool blkdev_pr_allowed(struct block_device *bdev, blk_mode_t mode) if (capable(CAP_SYS_ADMIN)) return true; + /* - * Only allow unprivileged reservations if the file descriptor is open - * for writing. + * Only allow unprivileged reservation _out_ commands if the file + * descriptor is open for writing. Allow reservation _in_ commands if + * the file descriptor is open for reading since they do not modify the + * device. */ - return mode & BLK_OPEN_WRITE; + if (dir == PR_IN) + return mode & BLK_OPEN_READ; + else + return mode & BLK_OPEN_WRITE; } static int blkdev_pr_register(struct block_device *bdev, blk_mode_t mode, @@ -339,7 +351,7 @@ static int blkdev_pr_register(struct block_device *bdev, blk_mode_t mode, const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops; struct pr_registration reg; - if (!blkdev_pr_allowed(bdev, mode)) + if (!blkdev_pr_allowed(bdev, mode, PR_OUT)) return -EPERM; if (!ops || !ops->pr_register) return -EOPNOTSUPP; @@ -357,7 +369,7 @@ static int blkdev_pr_reserve(struct block_device *bdev, blk_mode_t mode, const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops; struct pr_reservation rsv; - if (!blkdev_pr_allowed(bdev, mode)) + if (!blkdev_pr_allowed(bdev, mode, PR_OUT)) return -EPERM; if (!ops || !ops->pr_reserve) return -EOPNOTSUPP; @@ -375,7 +387,7 @@ static int blkdev_pr_release(struct block_device *bdev, blk_mode_t mode, const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops; struct pr_reservation rsv; - if (!blkdev_pr_allowed(bdev, mode)) + if (!blkdev_pr_allowed(bdev, mode, PR_OUT)) return -EPERM; if (!ops || !ops->pr_release) return -EOPNOTSUPP; @@ -393,7 +405,7 @@ static int blkdev_pr_preempt(struct block_device *bdev, blk_mode_t mode, const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops; struct pr_preempt p; - if (!blkdev_pr_allowed(bdev, mode)) + if (!blkdev_pr_allowed(bdev, mode, PR_OUT)) return -EPERM; if (!ops || !ops->pr_preempt) return -EOPNOTSUPP; @@ -411,7 +423,7 @@ static int blkdev_pr_clear(struct block_device *bdev, blk_mode_t mode, const struct pr_ops *ops = bdev->bd_disk->fops->pr_ops; struct pr_clear c; - if (!blkdev_pr_allowed(bdev, mode)) + if (!blkdev_pr_allowed(bdev, mode, PR_OUT)) return -EPERM; if (!ops || !ops->pr_clear) return -EOPNOTSUPP; @@ -434,7 +446,7 @@ static int blkdev_pr_read_keys(struct block_device *bdev, blk_mode_t mode, size_t keys_copy_len; int ret; - if (!blkdev_pr_allowed(bdev, mode)) + if (!blkdev_pr_allowed(bdev, mode, PR_IN)) return -EPERM; if (!ops || !ops->pr_read_keys) return -EOPNOTSUPP; @@ -486,7 +498,7 @@ static int blkdev_pr_read_reservation(struct block_device *bdev, struct pr_read_reservation out = {}; int ret; - if (!blkdev_pr_allowed(bdev, mode)) + if (!blkdev_pr_allowed(bdev, mode, PR_IN)) return -EPERM; if (!ops || !ops->pr_read_reservation) return -EOPNOTSUPP; |