Check for CAP_SYS_ADMIN before calling into the driver, similar to
blkdev_flushbuf(). This is safer and can spare a check in the driver.
(Currently BLKROSET is overridden by md and rbd, rbd is missing the
check. md has the check, but it covers a lot more than BLKROSET.)
Signed-off-by: Ilya Dryomov <idryomov@xxxxxxxxx>
---
Al, this appears to go back to your "[PATCH] block ioctl cleanup",
history commit c6973580141c. 2002 was a long time ago, but still ;)
Was there a reason you made BLKFLSBUF check for CAP_SYS_ADMIN before
->ioctl() and BLKROSET after?
---
block/ioctl.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/block/ioctl.c b/block/ioctl.c
index 0de02ee67eed..3f81bc50ac00 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -437,11 +437,12 @@ static int blkdev_roset(struct block_device *bdev, fmode_t mode,
{
int ret, n;
+ if (!capable(CAP_SYS_ADMIN))
+ return -EACCES;
+
ret = __blkdev_driver_ioctl(bdev, mode, cmd, arg);
if (!is_unrecognized_ioctl(ret))
return ret;
- if (!capable(CAP_SYS_ADMIN))
- return -EACCES;
if (get_user(n, (int __user *)arg))
return -EFAULT;
set_device_ro(bdev, n);
--
2.4.3
