From: Niklas Cassel <niklas.cassel@xxxxxxx>
commit 4d643b66089591b4769bcdb6fd1bfeff2fe301b8 upstream.
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@xxxxxxx>
Reviewed-by: Damien Le Moal <damien.lemoal@xxxxxxx>
Reviewed-by: Aravind Ramesh <aravind.ramesh@xxxxxxx>
Reviewed-by: Adam Manzanares <a.manzanares@xxxxxxxxxxx>
Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.10+
Link: https://lore.kernel.org/r/20210811110505.29649-3-Niklas.Cassel@xxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
block/blk-zoned.c | 3 ---
1 file changed, 3 deletions(-)
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -296,9 +296,6 @@ int blkdev_report_zones_ioctl(struct blo
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;
