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hwmon: scmi: Fix info[] allocation type

PATCH Applied Kees Cook 3 participants 4 messages Sep 17 – Sep 18

Subsystems (2)
Hardware monitoring System control & power/management interface (SCPI/SCMI) Message Protocol drivers
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Kees Cook

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#0 lore raw

PATCH 1/1 hwmon: scmi: Fix info[] allocation type

From: Kees Cook <[email protected]>

In preparation for making the devm_kmalloc family of allocators type aware, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (Before, the allocator would always return "void *", which can be implicitly cast to any pointer type.)

The assigned type of "scmi_sensors->info[type]" is
"const struct scmi_sensor_info **", but the converted allocation type would be "const struct scmi_sensor_info ***", as the size was taken from "*scmi_sensors->info", which is one level of indirection too many. Luckily both element types are pointers of the same size. Take the size from the element type of the assignment target.

Build tested ARCH=x86_64 allmodconfig with GCC 16.2.0:
drivers/hwmon/scmi-hwmon.o

Assisted-by LLM coccinelle
Signed-off-by Kees Cook <[email protected]>

---
Cc: Sudeep Holla <[email protected]>
Cc: Cristian Marussi <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>
Cc: <[email protected]>

---
 drivers/hwmon/scmi-hwmon.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
drivers/hwmon/scmi-hwmon.c +2 -1
index eec223d174c0..9ae8f774297e 100644
@@ -305,7 +305,8 @@ static int scmi_hwmon_probe(struct scmi_device *sdev)
 
 		scmi_sensors->info[type] =
 			devm_kcalloc(dev, nr_count[type],
-				     sizeof(*scmi_sensors->info), GFP_KERNEL);
+				     sizeof(*scmi_sensors->info[type]),
+				     GFP_KERNEL);
 		if (!scmi_sensors->info[type])
 			return -ENOMEM;
 	}
Signature · 1 line
2.34.1
AI review
#1 lore raw
Sashiko has reviewed this patch and found no issues. It looks great!
Quoted 15 lines

From: Kees Cook <[email protected]>

In preparation for making the devm_kmalloc family of allocators type aware, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (Before, the allocator would always return "void *", which can be implicitly cast to any pointer type.)

The assigned type of "scmi_sensors->info[type]" is
"const struct scmi_sensor_info **", but the converted allocation type would be "const struct scmi_sensor_info ***", as the size was taken from "*scmi_sensors->info", which is one level of indirection too many. Luckily both element types are pointers of the same size. Take the size from the element type of the assignment target.

Quoted 5 lines

Build tested ARCH=x86_64 allmodconfig with GCC 16.2.0:
drivers/hwmon/scmi-hwmon.o

Assisted-by LLM coccinelle
Signed-off-by Kees Cook <[email protected]>

Sashiko has reviewed this patch and found no issues. It looks great!

Signature · 1 line
Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=1
maintainer Applied
#2 lore raw
In reply to Kees Cook
Quoted 15 lines · Kees Cook

From: Kees Cook <[email protected]>

In preparation for making the devm_kmalloc family of allocators type aware, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (Before, the allocator would always return "void *", which can be implicitly cast to any pointer type.)

The assigned type of "scmi_sensors->info[type]" is
"const struct scmi_sensor_info **", but the converted allocation type would be "const struct scmi_sensor_info ***", as the size was taken from "*scmi_sensors->info", which is one level of indirection too many. Luckily both element types are pointers of the same size. Take the size from the element type of the assignment target.

Quoted 5 lines

Build tested ARCH=x86_64 allmodconfig with GCC 16.2.0:
drivers/hwmon/scmi-hwmon.o

Assisted-by LLM coccinelle
Signed-off-by Kees Cook <[email protected]>

Applied.

Thanks,
Guenter

maintainer Applied
#3 lore raw
In reply to Kees Cook
Quoted 15 lines · Kees Cook

From: Kees Cook <[email protected]>

In preparation for making the devm_kmalloc family of allocators type aware, we need to make sure that the returned type from the allocation matches the type of the variable being assigned. (Before, the allocator would always return "void *", which can be implicitly cast to any pointer type.)

The assigned type of "scmi_sensors->info[type]" is
"const struct scmi_sensor_info **", but the converted allocation type would be "const struct scmi_sensor_info ***", as the size was taken from "*scmi_sensors->info", which is one level of indirection too many. Luckily both element types are pointers of the same size. Take the size from the element type of the assignment target.

Quoted 5 lines

Build tested ARCH=x86_64 allmodconfig with GCC 16.2.0:
drivers/hwmon/scmi-hwmon.o

Assisted-by LLM coccinelle
Signed-off-by Kees Cook <[email protected]>

Applied.

Thanks,
Guenter