Kernel-Crash when working with ubt0
Maksim Yevmenkin
maksim.yevmenkin at gmail.com
Wed Aug 28 17:10:48 UTC 2019
> > > Hmm... interesting....
> > >
> > > I only took a brief look at it. I suppose I can ensure user space address is wired and then copyout() can be called with mutex held
> >
> > >No, you cannot do this, at least without making the kernel to panic.
> > User might unmap the wired mapping at any time still.
>
> Kostik,
>
> i was thinking along the lines of vslock/vsunlock and copyout_nofault.
> basically similar to the sysctl code. do you think this would not
> work?
actually, i dont think i need to hold lock over copyout. attached is
my version of the patch (untested)
thanks,
max
-------------- next part --------------
Index: ng_btsocket_hci_raw.c
===================================================================
diff --git a/head/sys/netgraph/bluetooth/socket/ng_btsocket_hci_raw.c b/head/sys/netgraph/bluetooth/socket/ng_btsocket_hci_raw.c
--- a/head/sys/netgraph/bluetooth/socket/ng_btsocket_hci_raw.c (revision 351568)
+++ b/head/sys/netgraph/bluetooth/socket/ng_btsocket_hci_raw.c (working copy)
@@ -1156,15 +1156,15 @@
if (p->num_entries <= 0 ||
p->num_entries > NG_HCI_MAX_NEIGHBOR_NUM ||
p->entries == NULL) {
- error = EINVAL;
- break;
+ mtx_unlock(&pcb->pcb_mtx);
+ return (EINVAL);
}
NG_MKMESSAGE(msg, NGM_HCI_COOKIE,
NGM_HCI_NODE_GET_NEIGHBOR_CACHE, 0, M_NOWAIT);
if (msg == NULL) {
- error = ENOMEM;
- break;
+ mtx_unlock(&pcb->pcb_mtx);
+ return (ENOMEM);
}
ng_btsocket_hci_raw_get_token(&msg->header.token);
pcb->token = msg->header.token;
@@ -1173,7 +1173,8 @@
NG_SEND_MSG_PATH(error, ng_btsocket_hci_raw_node, msg, path, 0);
if (error != 0) {
pcb->token = 0;
- break;
+ mtx_unlock(&pcb->pcb_mtx);
+ return (error);
}
error = msleep(&pcb->msg, &pcb->pcb_mtx,
@@ -1181,16 +1182,21 @@
ng_btsocket_hci_raw_ioctl_timeout * hz);
pcb->token = 0;
- if (error != 0)
- break;
+ if (error != 0) {
+ mtx_unlock(&pcb->pcb_mtx);
+ return (error);
+ }
- if (pcb->msg != NULL &&
- pcb->msg->header.cmd == NGM_HCI_NODE_GET_NEIGHBOR_CACHE) {
+ msg = pcb->msg;
+ pcb->msg = NULL;
+
+ mtx_unlock(&pcb->pcb_mtx);
+
+ if (msg != NULL &&
+ msg->header.cmd == NGM_HCI_NODE_GET_NEIGHBOR_CACHE) {
/* Return data back to user space */
- p1 = (ng_hci_node_get_neighbor_cache_ep *)
- (pcb->msg->data);
- p2 = (ng_hci_node_neighbor_cache_entry_ep *)
- (p1 + 1);
+ p1 = (ng_hci_node_get_neighbor_cache_ep *)(msg->data);
+ p2 = (ng_hci_node_neighbor_cache_entry_ep *)(p1 + 1);
p->num_entries = min(p->num_entries, p1->num_entries);
if (p->num_entries > 0)
@@ -1200,8 +1206,9 @@
} else
error = EINVAL;
- NG_FREE_MSG(pcb->msg); /* checks for != NULL */
- }break;
+ NG_FREE_MSG(msg); /* checks for != NULL */
+ return (error);
+ } /* NOTREACHED */
case SIOC_HCI_RAW_NODE_GET_CON_LIST: {
struct ng_btsocket_hci_raw_con_list *p =
@@ -1212,15 +1219,15 @@
if (p->num_connections == 0 ||
p->num_connections > NG_HCI_MAX_CON_NUM ||
p->connections == NULL) {
- error = EINVAL;
- break;
+ mtx_unlock(&pcb->pcb_mtx);
+ return (EINVAL);
}
NG_MKMESSAGE(msg, NGM_HCI_COOKIE, NGM_HCI_NODE_GET_CON_LIST,
0, M_NOWAIT);
if (msg == NULL) {
- error = ENOMEM;
- break;
+ mtx_unlock(&pcb->pcb_mtx);
+ return (ENOMEM);
}
ng_btsocket_hci_raw_get_token(&msg->header.token);
pcb->token = msg->header.token;
@@ -1229,7 +1236,8 @@
NG_SEND_MSG_PATH(error, ng_btsocket_hci_raw_node, msg, path, 0);
if (error != 0) {
pcb->token = 0;
- break;
+ mtx_unlock(&pcb->pcb_mtx);
+ return (error);
}
error = msleep(&pcb->msg, &pcb->pcb_mtx,
@@ -1237,13 +1245,20 @@
ng_btsocket_hci_raw_ioctl_timeout * hz);
pcb->token = 0;
- if (error != 0)
- break;
+ if (error != 0) {
+ mtx_unlock(&pcb->pcb_mtx);
+ return (error);
+ }
- if (pcb->msg != NULL &&
- pcb->msg->header.cmd == NGM_HCI_NODE_GET_CON_LIST) {
+ msg = pcb->msg;
+ pcb->msg = NULL;
+
+ mtx_unlock(&pcb->pcb_mtx);
+
+ if (msg != NULL &&
+ msg->header.cmd == NGM_HCI_NODE_GET_CON_LIST) {
/* Return data back to user space */
- p1 = (ng_hci_node_con_list_ep *)(pcb->msg->data);
+ p1 = (ng_hci_node_con_list_ep *)(msg->data);
p2 = (ng_hci_node_con_ep *)(p1 + 1);
p->num_connections = min(p->num_connections,
@@ -1255,8 +1270,9 @@
} else
error = EINVAL;
- NG_FREE_MSG(pcb->msg); /* checks for != NULL */
- } break;
+ NG_FREE_MSG(msg); /* checks for != NULL */
+ return (error);
+ } /* NOTREACHED */
case SIOC_HCI_RAW_NODE_GET_LINK_POLICY_MASK: {
struct ng_btsocket_hci_raw_node_link_policy_mask *p =
@@ -1332,15 +1348,15 @@
struct nodeinfo *ni = nl->names;
if (nl->num_names == 0) {
- error = EINVAL;
- break;
+ mtx_unlock(&pcb->pcb_mtx);
+ return (EINVAL);
}
NG_MKMESSAGE(msg, NGM_GENERIC_COOKIE, NGM_LISTNAMES,
0, M_NOWAIT);
if (msg == NULL) {
- error = ENOMEM;
- break;
+ mtx_unlock(&pcb->pcb_mtx);
+ return (ENOMEM);
}
ng_btsocket_hci_raw_get_token(&msg->header.token);
pcb->token = msg->header.token;
@@ -1349,7 +1365,8 @@
NG_SEND_MSG_PATH(error, ng_btsocket_hci_raw_node, msg, ".:", 0);
if (error != 0) {
pcb->token = 0;
- break;
+ mtx_unlock(&pcb->pcb_mtx);
+ return (error);
}
error = msleep(&pcb->msg, &pcb->pcb_mtx,
@@ -1357,12 +1374,19 @@
ng_btsocket_hci_raw_ioctl_timeout * hz);
pcb->token = 0;
- if (error != 0)
- break;
+ if (error != 0) {
+ mtx_unlock(&pcb->pcb_mtx);
+ return (error);
+ }
- if (pcb->msg != NULL && pcb->msg->header.cmd == NGM_LISTNAMES) {
+ msg = pcb->msg;
+ pcb->msg = NULL;
+
+ mtx_unlock(&pcb->pcb_mtx);
+
+ if (msg != NULL && msg->header.cmd == NGM_LISTNAMES) {
/* Return data back to user space */
- struct namelist *nl1 = (struct namelist *) pcb->msg->data;
+ struct namelist *nl1 = (struct namelist *) msg->data;
struct nodeinfo *ni1 = &nl1->nodeinfo[0];
while (nl->num_names > 0 && nl1->numnames > 0) {
@@ -1385,8 +1409,9 @@
} else
error = EINVAL;
- NG_FREE_MSG(pcb->msg); /* checks for != NULL */
- } break;
+ NG_FREE_MSG(msg); /* checks for != NULL */
+ return (error);
+ } /* NOTREACHED */
default:
error = EINVAL;
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