Commit 8ed1c683 authored by Zicheng Qu's avatar Zicheng Qu Committed by Wen Zhiwei
Browse files

iio: gts: fix infinite loop for gain_to_scaletables() 

stable inclusion
from stable-v6.6.64
commit 1bdff8a19cd6f7ef76eba3e6739d0f1702d49f06
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/IBL4B6

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=1bdff8a19cd6f7ef76eba3e6739d0f1702d49f06



--------------------------------

commit 7452f8a0814bb73f739ee0dab60f099f3361b151 upstream.

In iio_gts_build_avail_time_table(), it is checked that gts->num_itime is
non-zero, but gts->num_itime is not checked in gain_to_scaletables(). The
variable time_idx is initialized as gts->num_itime - 1. This implies that
time_idx might initially be set to -1 (0 - 1 = -1). Consequently, using
while (time_idx--) could lead to an infinite loop.

Cc: stable@vger.kernel.org # v6.6+
Fixes: 38416c28 ("iio: light: Add gain-time-scale helpers")
Signed-off-by: default avatarZicheng Qu <quzicheng@huawei.com>
Reviewed-by: default avatarMatti Vaittinen <mazziesaccount@gmail.com>
Link: https://patch.msgid.link/20241031014626.2313077-1-quzicheng@huawei.com


Signed-off-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarWen Zhiwei <wenzhiwei@kylinos.cn>
parent 14659c1a

drivers/iio/industrialio-gts-helper.c

+1 −1
Original line number Diff line number Diff line
@@ -205,7 +205,7 @@ static int gain_to_scaletables(struct iio_gts *gts, int **gains, int **scales) 
	memcpy(all_gains, gains[time_idx], gain_bytes);

	new_idx = gts->num_hwgain;



	while (time_idx--) {

	while (time_idx-- > 0) {

		for (j = 0; j < gts->num_hwgain; j++) {

			int candidate = gains[time_idx][j];

			int chk;