Messages in this thread Patch in this message | | | From | Seth Forshee <> | Subject | [RFC PATCH 08/11] block: Allow blkdev ioctls within user namespaces | Date | Wed, 14 May 2014 16:34:56 -0500 |
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Many blkdev ioctls require CAP_SYS_ADMIN, preventing them from being used on block devices owned by unpriveleged user namespaces. Change this to requiring only CAP_SYS_ADMIN within the namespace which owns the device. Most devices are owned by init_user_ns, and in that case this check is equivalent.
Signed-off-by: Seth Forshee <seth.forshee@canonical.com> --- block/compat_ioctl.c | 3 ++- block/ioctl.c | 16 ++++++++-------- 2 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/block/compat_ioctl.c b/block/compat_ioctl.c index fbd5a67cb773..b16745d14ac2 100644 --- a/block/compat_ioctl.c +++ b/block/compat_ioctl.c @@ -10,6 +10,7 @@ #include <linux/syscalls.h> #include <linux/types.h> #include <linux/uaccess.h> +#include <linux/user_namespace.h> static int compat_put_ushort(unsigned long arg, unsigned short val) { @@ -725,7 +726,7 @@ long compat_blkdev_ioctl(struct file *file, unsigned cmd, unsigned long arg) !blk_queue_nonrot(bdev_get_queue(bdev))); case BLKRASET: /* compatible, but no compat_ptr (!) */ case BLKFRASET: - if (!capable(CAP_SYS_ADMIN)) + if (!ns_capable(disk_to_dev(disk)->ns, CAP_SYS_ADMIN)) return -EACCES; bdi = blk_get_backing_dev_info(bdev); if (bdi == NULL) diff --git a/block/ioctl.c b/block/ioctl.c index 7d5c3b20af45..45bb28d59b56 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -7,12 +7,13 @@ #include <linux/backing-dev.h> #include <linux/fs.h> #include <linux/blktrace_api.h> +#include <linux/user_namespace.h> #include <asm/uaccess.h> static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user *arg) { struct block_device *bdevp; - struct gendisk *disk; + struct gendisk *disk = bdev->bd_disk; struct hd_struct *part, *lpart; struct blkpg_ioctl_arg a; struct blkpg_partition p; @@ -20,13 +21,12 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user long long start, length; int partno; - if (!capable(CAP_SYS_ADMIN)) + if (!ns_capable(disk_to_dev(disk)->ns, CAP_SYS_ADMIN)) return -EACCES; if (copy_from_user(&a, arg, sizeof(struct blkpg_ioctl_arg))) return -EFAULT; if (copy_from_user(&p, a.data, sizeof(struct blkpg_partition))) return -EFAULT; - disk = bdev->bd_disk; if (bdev != bdev->bd_contains) return -EINVAL; partno = p.pno; @@ -157,7 +157,7 @@ static int blkdev_reread_part(struct block_device *bdev) if (!disk_part_scan_enabled(disk) || bdev != bdev->bd_contains) return -EINVAL; - if (!capable(CAP_SYS_ADMIN)) + if (!ns_capable(disk_to_dev(disk)->ns, CAP_SYS_ADMIN)) return -EACCES; if (!mutex_trylock(&bdev->bd_mutex)) return -EBUSY; @@ -281,7 +281,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, switch(cmd) { case BLKFLSBUF: - if (!capable(CAP_SYS_ADMIN)) + if (!ns_capable(disk_to_dev(disk)->ns, CAP_SYS_ADMIN)) return -EACCES; ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); @@ -296,7 +296,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg); if (!is_unrecognized_ioctl(ret)) return ret; - if (!capable(CAP_SYS_ADMIN)) + if (!ns_capable(disk_to_dev(disk)->ns, CAP_SYS_ADMIN)) return -EACCES; if (get_user(n, (int __user *)(arg))) return -EFAULT; @@ -380,7 +380,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, return put_ushort(arg, !blk_queue_nonrot(bdev_get_queue(bdev))); case BLKRASET: case BLKFRASET: - if(!capable(CAP_SYS_ADMIN)) + if(!ns_capable(disk_to_dev(disk)->ns, CAP_SYS_ADMIN)) return -EACCES; bdi = blk_get_backing_dev_info(bdev); if (bdi == NULL) @@ -389,7 +389,7 @@ int blkdev_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd, return 0; case BLKBSZSET: /* set the logical block size */ - if (!capable(CAP_SYS_ADMIN)) + if (!ns_capable(disk_to_dev(disk)->ns, CAP_SYS_ADMIN)) return -EACCES; if (!arg) return -EINVAL; -- 1.9.1
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