Commit a10c0ce7 authored by Clemens Ladisch's avatar Clemens Ladisch Committed by Stefan Richter

firewire: check cdev response length

Add a check that the data length in the SEND_RESPONSE ioctl is correct.
Incidentally, this also fixes the previously wrong response length of
software-handled lock requests.
Signed-off-by: default avatarClemens Ladisch <clemens@ladisch.de>
Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 262444ee
......@@ -756,9 +756,12 @@ static int ioctl_send_response(struct client *client, union ioctl_arg *arg)
if (is_fcp_request(r->request))
goto out;
if (a->length < r->length)
r->length = a->length;
if (copy_from_user(r->data, u64_to_uptr(a->data), r->length)) {
if (a->length != fw_get_response_length(r->request)) {
ret = -EINVAL;
kfree(r->request);
goto out;
}
if (copy_from_user(r->data, u64_to_uptr(a->data), a->length)) {
ret = -EFAULT;
kfree(r->request);
goto out;
......
......@@ -580,6 +580,41 @@ static void free_response_callback(struct fw_packet *packet,
kfree(request);
}
int fw_get_response_length(struct fw_request *r)
{
int tcode, ext_tcode, data_length;
tcode = HEADER_GET_TCODE(r->request_header[0]);
switch (tcode) {
case TCODE_WRITE_QUADLET_REQUEST:
case TCODE_WRITE_BLOCK_REQUEST:
return 0;
case TCODE_READ_QUADLET_REQUEST:
return 4;
case TCODE_READ_BLOCK_REQUEST:
data_length = HEADER_GET_DATA_LENGTH(r->request_header[3]);
return data_length;
case TCODE_LOCK_REQUEST:
ext_tcode = HEADER_GET_EXTENDED_TCODE(r->request_header[3]);
data_length = HEADER_GET_DATA_LENGTH(r->request_header[3]);
switch (ext_tcode) {
case EXTCODE_FETCH_ADD:
case EXTCODE_LITTLE_ADD:
return data_length;
default:
return data_length / 2;
}
default:
WARN(1, KERN_ERR "wrong tcode %d", tcode);
return 0;
}
}
void fw_fill_response(struct fw_packet *response, u32 *request_header,
int rcode, void *payload, size_t length)
{
......@@ -713,7 +748,8 @@ void fw_send_response(struct fw_card *card,
if (rcode == RCODE_COMPLETE)
fw_fill_response(&request->response, request->request_header,
rcode, request->data, request->length);
rcode, request->data,
fw_get_response_length(request));
else
fw_fill_response(&request->response, request->request_header,
rcode, NULL, 0);
......
......@@ -218,6 +218,7 @@ static inline bool is_next_generation(int new_generation, int old_generation)
void fw_core_handle_request(struct fw_card *card, struct fw_packet *request);
void fw_core_handle_response(struct fw_card *card, struct fw_packet *packet);
int fw_get_response_length(struct fw_request *request);
void fw_fill_response(struct fw_packet *response, u32 *request_header,
int rcode, void *payload, size_t length);
void fw_send_phy_config(struct fw_card *card,
......
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