Commit 3e0b5f0d authored by Stefan Richter's avatar Stefan Richter

firewire: cdev: address handler input validation

Like before my commit 1415d918,
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: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 45ee3199
......@@ -591,9 +591,10 @@ static int ioctl_allocate(struct client *client, void *buffer)
handler->closure = request->closure;
handler->client = client;
if (fw_core_add_address_handler(&handler->handler, &region) < 0) {
ret = fw_core_add_address_handler(&handler->handler, &region);
if (ret < 0) {
kfree(handler);
return -EBUSY;
return ret;
}
handler->resource.release = release_address_handler;
......
......@@ -449,16 +449,19 @@ const struct fw_address_region fw_unit_space_region =
#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 @@ fw_core_add_address_handler(struct fw_address_handler *handler,
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;
......
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