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Commit f0319748 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

s390/sclp: always stay within bounds of the early sccb 



Make sure the _sclp_print_lm function stays within bounds of the early
sccb, even if the passed string is very long.  If the string is too
long, the remaining characters will be dropped.

Suggested-by: default avatarPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: default avatarPeter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 742dc577

arch/s390/kernel/sclp.c

+6 −1
Original line number Diff line number Diff line
@@ -132,16 +132,21 @@ static void _sclp_print_lm(const char *str) 
		0x10, 0x00,					/* 4 */

		0x00, 0x00, 0x00, 0x00				/* 6 */

	};

	unsigned char *ptr, ch;

	unsigned char *ptr, *end_ptr, ch;

	unsigned int count;



	memcpy(_sclp_work_area, write_head, sizeof(write_head));

	ptr = _sclp_work_area + sizeof(write_head);

	end_ptr = _sclp_work_area + sizeof(_sclp_work_area) - 1;

	do {

		if (ptr + sizeof(write_mto) > end_ptr)

			break;

		memcpy(ptr, write_mto, sizeof(write_mto));

		for (count = sizeof(write_mto); (ch = *str++) != 0; count++) {

			if (ch == 0x0a)

				break;

			if (ptr > end_ptr)

				break;

			ptr[count] = _ascebc[ch];

		}

		/* Update length fields in mto, mdb, evbuf and sccb */