firewire: cdev: address handler input validation
Like before my commit 1415d9189e8c59aa9c77a3bba419dcea062c145f,
fw_core_add_address_handler() does not align the address region now.
Instead the caller is required to pass valid parameters.
Since one of the callers of fw_core_add_address_handler() is the cdev
userspace interface, we now check for valid input. If the client is
buggy, we give it a hint with -EINVAL.
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-transaction.c b/drivers/firewire/fw-transaction.c
index 699ac04..12a6cdc 100644
--- a/drivers/firewire/fw-transaction.c
+++ b/drivers/firewire/fw-transaction.c
@@ -449,16 +449,19 @@
#endif /* 0 */
/**
- * Allocate a range of addresses in the node space of the OHCI
- * controller. When a request is received that falls within the
- * specified address range, the specified callback is invoked. The
- * parameters passed to the callback give the details of the
- * particular request.
+ * fw_core_add_address_handler - register for incoming requests
+ * @handler: callback
+ * @region: region in the IEEE 1212 node space address range
+ *
+ * region->start, ->end, and handler->length have to be quadlet-aligned.
+ *
+ * When a request is received that falls within the specified address range,
+ * the specified callback is invoked. The parameters passed to the callback
+ * give the details of the particular request.
*
* Return value: 0 on success, non-zero otherwise.
* The start offset of the handler's address region is determined by
* fw_core_add_address_handler() and is returned in handler->offset.
- * The offset is quadlet-aligned.
*/
int
fw_core_add_address_handler(struct fw_address_handler *handler,
@@ -468,17 +471,23 @@
unsigned long flags;
int ret = -EBUSY;
+ if (region->start & 0xffff000000000003ULL ||
+ region->end & 0xffff000000000003ULL ||
+ region->start >= region->end ||
+ handler->length & 3 ||
+ handler->length == 0)
+ return -EINVAL;
+
spin_lock_irqsave(&address_handler_lock, flags);
- handler->offset = roundup(region->start, 4);
+ handler->offset = region->start;
while (handler->offset + handler->length <= region->end) {
other =
lookup_overlapping_address_handler(&address_handler_list,
handler->offset,
handler->length);
if (other != NULL) {
- handler->offset =
- roundup(other->offset + other->length, 4);
+ handler->offset += other->length;
} else {
list_add_tail(&handler->link, &address_handler_list);
ret = 0;