[PATCH 2/2] blk-zoned: allow BLKREPORTZONE without CAP_SYS_ADMIN

From: Niklas Cassel
Date: Mon May 31 2021 - 10:42:02 EST


From: Niklas Cassel <niklas.cassel@xxxxxxx>

Performing a BLKREPORTZONE operation should be allowed under the same
permissions as read(). (read() does not require CAP_SYS_ADMIN).

Remove the CAP_SYS_ADMIN requirement, and instead check that the fd was
successfully opened with FMODE_READ. This way BLKREPORTZONE will match
the access control requirement of read().

Signed-off-by: Niklas Cassel <niklas.cassel@xxxxxxx>
---
block/blk-zoned.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 0789e6e9f7db..e05fe8dbb06d 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -288,8 +288,8 @@ 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 (!(mode & FMODE_READ))
+ return -EBADF;

if (copy_from_user(&rep, argp, sizeof(struct blk_zone_report)))
return -EFAULT;
--
2.31.1