From: Niklas Cassel niklas.cassel@wdc.com
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 Cc: stable@vger.kernel.org # v4.10+ --- Changes since v2: -Drop the FMODE_READ check. Right now it is possible to open() the device with O_WRONLY and get the zone report from that fd. Therefore adding a FMODE_READ check on BLKREPORTZONE would break existing applications. Instead, just remove the existing CAP_SYS_ADMIN check.
block/blk-zoned.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 0789e6e9f7db..457eceabed2e 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -288,9 +288,6 @@ 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;
On 2021/06/14 21:23, Niklas Cassel wrote:
From: Niklas Cassel niklas.cassel@wdc.com
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 Cc: stable@vger.kernel.org # v4.10+
Changes since v2: -Drop the FMODE_READ check. Right now it is possible to open() the device with O_WRONLY and get the zone report from that fd. Therefore adding a FMODE_READ check on BLKREPORTZONE would break existing applications. Instead, just remove the existing CAP_SYS_ADMIN check.
block/blk-zoned.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 0789e6e9f7db..457eceabed2e 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -288,9 +288,6 @@ 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;
Looks good.
Reviewed-by: Damien Le Moal damien.lemoal@dc.com
-----Original Message----- From: Niklas Cassel Niklas.Cassel@wdc.com Sent: Monday, June 14, 2021 5:53 PM To: Jens Axboe axboe@kernel.dk; Hannes Reinecke hare@suse.com; Martin K. Petersen martin.petersen@oracle.com; Damien Le Moal Damien.LeMoal@wdc.com; Shaun Tancheff shaun@tancheff.com Cc: Damien Le Moal Damien.LeMoal@wdc.com; Niklas Cassel Niklas.Cassel@wdc.com; stable@vger.kernel.org; Jens Axboe axboe@fb.com; linux-block@vger.kernel.org; linux-kernel@vger.kernel.org Subject: [PATCH v3 2/2] blk-zoned: allow BLKREPORTZONE without CAP_SYS_ADMIN
From: Niklas Cassel niklas.cassel@wdc.com
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 Cc: stable@vger.kernel.org # v4.10+
Changes since v2: -Drop the FMODE_READ check. Right now it is possible to open() the device with O_WRONLY and get the zone report from that fd. Therefore adding a FMODE_READ check on BLKREPORTZONE would break existing applications. Instead, just remove the existing CAP_SYS_ADMIN check.
block/blk-zoned.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 0789e6e9f7db..457eceabed2e 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -288,9 +288,6 @@ 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;
-- 2.31.1
Looks good,
Reviewed-by: Aravind Ramesh aravind.ramesh@wdc.com
On Mon, Jun 14, 2021 at 12:23:21PM +0000, Niklas Cassel wrote:
From: Niklas Cassel niklas.cassel@wdc.com
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 Cc: stable@vger.kernel.org # v4.10+
Changes since v2: -Drop the FMODE_READ check. Right now it is possible to open() the device with O_WRONLY and get the zone report from that fd. Therefore adding a FMODE_READ check on BLKREPORTZONE would break existing applications. Instead, just remove the existing CAP_SYS_ADMIN check.
block/blk-zoned.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 0789e6e9f7db..457eceabed2e 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -288,9 +288,6 @@ 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;
2.31.1
LGTM
Reviewed-by: Adam Manzanares a.manzanares@samsung.com
On 6/14/21 7:23 AM, Niklas Cassel wrote:
From: Niklas Cassel niklas.cassel@wdc.com
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 Cc: stable@vger.kernel.org # v4.10+
Changes since v2: -Drop the FMODE_READ check. Right now it is possible to open() the device with O_WRONLY and get the zone report from that fd. Therefore adding a FMODE_READ check on BLKREPORTZONE would break existing applications. Instead, just remove the existing CAP_SYS_ADMIN check.
block/blk-zoned.c | 3 --- 1 file changed, 3 deletions(-)
diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 0789e6e9f7db..457eceabed2e 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -288,9 +288,6 @@ 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;
Looks Good.
Reviewed-by: Himanshu Madhani himanshu.madhani@oracle.com
linux-stable-mirror@lists.linaro.org
-
Adam Manzanares -
Aravind Ramesh -
Damien Le Moal -
Himanshu Madhani -
Niklas Cassel