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mem-leak fix for acpi_thermal_write_trip_points()

PATCH New Jesper Juhl 1 participant 1 message May 14, 2006

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PATCH 1/1 mem-leak fix for acpi_thermal_write_trip_points()

There's a memory leak in
drivers/acpi/thermal.c::acpi_thermal_write_trip_points()
found by the Coverity checker as bug #1243

The problem is simply that if the allocation of 'active' fails, then we'll return from the function without freeing the memory previously allocated to 'limit_string'.

One fix would have been the insertion of kfree(limit_string); just before the return_VALUE(-ENOMEM); call, but I chose a different fix. Except for this one return the function only has a single exit point at the end: label, and there it does proper cleanup of everything. So even though setting the return value (the 'count' variable) and jumping there results in a pointless kfree(NULL) call (since 'active' will be NULL), I thought this was a small price to pay for the bennefit of having just a single exit path for the function.

---

 drivers/acpi/thermal.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)
drivers/acpi/thermal.c +4 -2
@@ -942,8 +942,10 @@ acpi_thermal_write_trip_points(struct fi
 	memset(limit_string, 0, ACPI_THERMAL_MAX_LIMIT_STR_LEN);
 
 	active = kmalloc(ACPI_THERMAL_MAX_ACTIVE * sizeof(int), GFP_KERNEL);
-	if (!active)
-		return_VALUE(-ENOMEM);
+	if (!active) {
+		count = -ENOMEM;
+		goto end;
+	}
 
 	if (!tz || (count > ACPI_THERMAL_MAX_LIMIT_STR_LEN - 1)) {
 		ACPI_DEBUG_PRINT((ACPI_DB_ERROR, "Invalid argument\n"));