Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 52db45c3 authored by Stefan Weinhuber's avatar Stefan Weinhuber Committed by Martin Schwidefsky
Browse files

[S390] dasd: fix idaw boundary checking for track based ccw 



A ccw command that reads or writes several records at once will
usually transfer more data then fits into one page and needs to
address memory areas using a list of indirect data address words
(idaw). All but the first of these areas must start on a 4KB or 2KB
block boundary (depending on the idaw format).
A check for this restriction was missing and has been added with
this patch.

Signed-off-by: default avatarStefan Weinhuber <wein@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent f3445a1a

drivers/s390/block/dasd_eckd.c

+12 −4
Original line number Diff line number Diff line
@@ -2019,15 +2019,23 @@ static struct dasd_ccw_req *dasd_eckd_build_cp_cmd_track( 
				ccw++;

				recid += count;

				new_track = 0;

				/* first idaw for a ccw may start anywhere */

				if (!idaw_dst)

					idaw_dst = dst;

			}

			/* If we start a new idaw, everything is fine and the

			 * start of the new idaw is the start of this segment.

			/* If we start a new idaw, we must make sure that it

			 * starts on an IDA_BLOCK_SIZE boundary.

			 * If we continue an idaw, we must make sure that the

			 * current segment begins where the so far accumulated

			 * idaw ends

			 */

			if (!idaw_dst)

			if (!idaw_dst) {

				if (__pa(dst) & (IDA_BLOCK_SIZE-1)) {

					dasd_sfree_request(cqr, startdev);

					return ERR_PTR(-ERANGE);

				} else

					idaw_dst = dst;

			}

			if ((idaw_dst + idaw_len) != dst) {

				dasd_sfree_request(cqr, startdev);

				return ERR_PTR(-ERANGE);