[PATCH 3.18 06/13] vsock: cope with memory allocation failure at socket creation time

From: Greg Kroah-Hartman
Date: Thu Feb 21 2019 - 09:37:09 EST

3.18-stable review patch. If anyone has any objections, please let me know.


From: Paolo Abeni <pabeni@xxxxxxxxxx>

[ Upstream commit 225d9464268599a5b4d094d02ec17808e44c7553 ]

In the unlikely event that the kmalloc call in vmci_transport_socket_init()
fails, we end-up calling vmci_transport_destruct() with a NULL vmci_trans()
and oopsing.

This change addresses the above explicitly checking for zero vmci_trans()
at destruction time.

Reported-by: Xiumei Mu <xmu@xxxxxxxxxx>
Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Reviewed-by: Jorgen Hansen <jhansen@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
net/vmw_vsock/vmci_transport.c | 4 ++++
1 file changed, 4 insertions(+)

--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -1663,6 +1663,10 @@ static int vmci_transport_socket_init(st

static void vmci_transport_destruct(struct vsock_sock *vsk)
+ /* transport can be NULL if we hit a failure at init() time */
+ if (!vmci_trans(vsk))
+ return;
if (vmci_trans(vsk)->attach_sub_id != VMCI_INVALID_ID) {
vmci_trans(vsk)->attach_sub_id = VMCI_INVALID_ID;