RE: [PATCH v3 1/2] blk-zoned: allow zone management send operations without CAP_SYS_ADMIN

[Aravind Ramesh]

> -----Original Message-----
> From: Niklas Cassel <Niklas.Cassel@xxxxxxx>
> Sent: Monday, June 14, 2021 5:53 PM
> To: Jens Axboe <axboe@xxxxxxxxx>; Damien Le Moal <Damien.LeMoal@xxxxxxx>;
> Shaun Tancheff <shaun@xxxxxxxxxxxx>; Martin K. Petersen
> <martin.petersen@xxxxxxxxxx>; Hannes Reinecke <hare@xxxxxxxx>
> Cc: Damien Le Moal <Damien.LeMoal@xxxxxxx>; Niklas Cassel
> <Niklas.Cassel@xxxxxxx>; stable@xxxxxxxxxxxxxxx; Jens Axboe <axboe@xxxxxx>;
> linux-block@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> Subject: [PATCH v3 1/2] blk-zoned: allow zone management send operations
> without CAP_SYS_ADMIN
> 
> From: Niklas Cassel <niklas.cassel@xxxxxxx>
> 
> Zone management send operations (BLKRESETZONE, BLKOPENZONE,
> BLKCLOSEZONE and BLKFINISHZONE) should be allowed under the same permissions
> as write().
> (write() does not require CAP_SYS_ADMIN).
> 
> Additionally, other ioctls like BLKSECDISCARD and BLKZEROOUT only check if the fd
> was successfully opened with FMODE_WRITE.
> (They do not require CAP_SYS_ADMIN).
> 
> Currently, zone management send operations require both CAP_SYS_ADMIN and
> that the fd was successfully opened with FMODE_WRITE.
> 
> Remove the CAP_SYS_ADMIN requirement, so that zone management send
> operations match the access control requirement of write(), BLKSECDISCARD and
> BLKZEROOUT.
> 
> Fixes: 3ed05a987e0f ("blk-zoned: implement ioctls")
> Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxx>
> Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx # v4.10+
> ---
> Changes since v2:
> -None
> 
> Note to backporter:
> Function was added as blkdev_reset_zones_ioctl() in v4.10.
> Function was renamed to blkdev_zone_mgmt_ioctl() in v5.5.
> The patch is valid both before and after the function rename.
> 
>  block/blk-zoned.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/block/blk-zoned.c b/block/blk-zoned.c index
> 250cb76ee615..0789e6e9f7db 100644
> --- a/block/blk-zoned.c
> +++ b/block/blk-zoned.c
> @@ -349,9 +349,6 @@ int blkdev_zone_mgmt_ioctl(struct block_device *bdev,
> fmode_t mode,
>  	if (!blk_queue_is_zoned(q))
>  		return -ENOTTY;
> 
> -	if (!capable(CAP_SYS_ADMIN))
> -		return -EACCES;
> -
>  	if (!(mode & FMODE_WRITE))
>  		return -EBADF;
> 
> --
> 2.31.1

Looks good,

Reviewed-by: Aravind Ramesh <aravind.ramesh@xxxxxxx>