Commit d00c0ea1 authored by Uday Shankar's avatar Uday Shankar Committed by Jens Axboe
Browse files

ublk: check recovery flags for validity 



Setting UBLK_F_USER_RECOVERY_REISSUE without also setting
UBLK_F_USER_RECOVERY is currently silently equivalent to not setting any
recovery flags at all, even though that's obviously not intended. Check
for this case and fail add_dev (with a paranoid warning to aid debugging
any program which might rely on the old behavior) with EINVAL if it is
detected.

Signed-off-by: default avatarUday Shankar <ushankar@purestorage.com>
Reviewed-by: default avatarMing Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20241007182419.3263186-2-ushankar@purestorage.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 110234da

drivers/block/ublk_drv.c

+11 −0
Original line number Diff line number Diff line
@@ -62,6 +62,9 @@ 
		| UBLK_F_USER_COPY \

		| UBLK_F_ZONED)



#define UBLK_F_ALL_RECOVERY_FLAGS (UBLK_F_USER_RECOVERY \

		| UBLK_F_USER_RECOVERY_REISSUE)



/* All UBLK_PARAM_TYPE_* should be included here */

#define UBLK_PARAM_TYPE_ALL                                \

	(UBLK_PARAM_TYPE_BASIC | UBLK_PARAM_TYPE_DISCARD | \
@@ -2372,6 +2375,14 @@ static int ublk_ctrl_add_dev(struct io_uring_cmd *cmd) 
	else if (!(info.flags & UBLK_F_UNPRIVILEGED_DEV))

		return -EPERM;



	/* forbid nonsense combinations of recovery flags */

	if ((info.flags & UBLK_F_USER_RECOVERY_REISSUE) &&

	    !(info.flags & UBLK_F_USER_RECOVERY)) {

		pr_warn("%s: invalid recovery flags %llx\n", __func__,

			info.flags & UBLK_F_ALL_RECOVERY_FLAGS);

		return -EINVAL;

	}



	/*

	 * unprivileged device can't be trusted, but RECOVERY and

	 * RECOVERY_REISSUE still may hang error handling, so can't