dmaengine: imx-sdma: fix size check for sdma script_number

dmaengine: imx-sdma: fix size check for sdma script_number

[ Upstream commit bd73dfabdda280fc5f05bdec79b6721b4b2f035f ]

Illegal memory will be touch if SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V3
(41) exceed the size of structure sdma_script_start_addrs(40),
thus cause memory corrupt such as slob block header so that kernel
trap into while() loop forever in slob_free(). Please refer to below
code piece in imx-sdma.c:
for (i = 0; i < sdma->script_number; i++)
	if (addr_arr[i] > 0)
		saddr_arr[i] = addr_arr[i]; /* memory corrupt here */
That issue was brought by commit a572460be9cf ("dmaengine: imx-sdma: Add
support for version 3 firmware") because SDMA_SCRIPT_ADDRS_ARRAY_SIZE_V3
(38->41 3 scripts added) not align with script number added in
sdma_script_start_addrs(2 scripts).

Fixes: a572460be9cf ("dmaengine: imx-sdma: Add support for version 3 firmware")
Cc: stable@vger.kernel
Link: https://www.spinics.net/lists/arm-kernel/msg754895.html
Signed-off-by: Robin Gong <yibin.gong@nxp.com>
Reported-by: Jurgen Lambrecht <J.Lambrecht@TELEVIC.com>
Link: https://lore.kernel.org/r/1569347584-3478-1-git-send-email-yibin.gong@nxp.com
[vkoul: update the patch title]
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>