[PATCH 5.14 623/849] soundwire: bus: stop dereferencing invalid slave pointer

Greg Kroah-Hartman
2021-11-15T23:13:16Z

From: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>

[ Upstream commit 4cbbe74d906be0bcffbe1e74b43a00f99626a69c ]

Slave pointer is invalid after end of list iteration, using this
would result in below Memory abort.

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
...
Call trace:
__dev_printk+0x34/0x7c
_dev_warn+0x6c/0x90
sdw_bus_exit_clk_stop+0x194/0x1d0
swrm_runtime_resume+0x13c/0x238
pm_generic_runtime_resume+0x2c/0x48
__rpm_callback+0x44/0x150
rpm_callback+0x6c/0x78
rpm_resume+0x314/0x558
rpm_resume+0x378/0x558
rpm_resume+0x378/0x558
__pm_runtime_resume+0x3c/0x88

Use bus->dev instead to print this error message.

Fixes: b50bb8ba369cd ("soundwire: bus: handle -ENODATA errors in clock stop/start sequences")
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20211012101521.32087-1-srinivas.kandagatla@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/soundwire/bus.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c
index 3e6d4addac2f6..98c526aaf24b8 100644
--- a/drivers/soundwire/bus.c
+++ b/drivers/soundwire/bus.c
@@ -1103,7 +1103,7 @@ int sdw_bus_exit_clk_stop(struct sdw_bus *bus)
if (!simple_clk_stop) {
ret = sdw_bus_wait_for_clk_prep_deprep(bus, SDW_BROADCAST_DEV_NUM);
if (ret < 0)
- dev_warn(&slave->dev, "clock stop deprepare wait failed:%d\n", ret);
+ dev_warn(bus->dev, "clock stop deprepare wait failed:%d\n", ret);
}

list_for_each_entry(slave, &bus->slaves, node) {
--
2.33.0