Commit 12d4fd9a authored by Harshit Mogalapalli's avatar Harshit Mogalapalli Committed by Vinod Koul
Browse files

soundwire: bus: fix off-by-one when allocating slave IDs 



ida_alloc_max() interprets its max argument as inclusive.

Using SDW_FW_MAX_DEVICES(16) therefore allows an ID of 16 to be
allocated, but the IRQ domain created for the bus is sized for IDs
0-15.  If 16 is returned, irq_create_mapping() fails and the driver
ends up with an invalid IRQ mapping.

Limit the allocation to 0-15 by passing SDW_FW_MAX_DEVICES - 1.

Reported-by: default avatarkernel test robot <lkp@intel.com>
Reported-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/202512240450.hlDH3nCs-lkp@intel.com/


Fixes: aab12022 ("soundwire: bus: Add internal slave ID and use for IRQs")
Signed-off-by: default avatarHarshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reviewed-by: default avatarCharles Keepax <ckeepax@opensource.cirrus.com>
Link: https://patch.msgid.link/20260110201959.2523024-1-harshit.m.mogalapalli@oracle.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 8f0b4cce

drivers/soundwire/bus_type.c

+1 −1
Original line number Diff line number Diff line
@@ -105,7 +105,7 @@ static int sdw_drv_probe(struct device *dev) 
	if (ret)

		return ret;



	ret = ida_alloc_max(&slave->bus->slave_ida, SDW_FW_MAX_DEVICES, GFP_KERNEL);

	ret = ida_alloc_max(&slave->bus->slave_ida, SDW_FW_MAX_DEVICES - 1, GFP_KERNEL);

	if (ret < 0) {

		dev_err(dev, "Failed to allocated ID: %d\n", ret);

		return ret;