input: limit memory allocated by uinput ff drivers

input: limit memory allocated by uinput ff drivers

[Chuck Ebbert]

input: limit memory allocated by uinput ff drivers

Don't let force feedback drivers allocate more than 256K of kernel
memory. On kernel 2.6.22 this causes a kernel OOPS with the SLUB
memory allocator; on later kernels the drivers may allocate large
amounts of memory.

Signed-off-by: Chuck Ebbert <cebbert@redhat.com>

---
 drivers/input/ff-core.c |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- linux-2.6.22.noarch.orig/drivers/input/ff-core.c
+++ linux-2.6.22.noarch/drivers/input/ff-core.c
@@ -306,6 +306,7 @@ int input_ff_create(struct input_dev *de
 {
 	struct ff_device *ff;
 	int i;
+	int needed_mem;
 
 	if (!max_effects) {
 		printk(KERN_ERR
@@ -313,8 +314,11 @@ int input_ff_create(struct input_dev *de
 		return -EINVAL;
 	}
 
-	ff = kzalloc(sizeof(struct ff_device) +
-		     max_effects * sizeof(struct file *), GFP_KERNEL);
+	needed_mem = sizeof(struct ff_device) + max_effects * sizeof(struct file *);
+	if (needed_mem > 256 * 1024)
+		return -ENOMEM;
+
+	ff = kzalloc(needed_mem, GFP_KERNEL);
 	if (!ff)
 		return -ENOMEM;