[PATCH 4.20 04/32] vsock: cope with memory allocation failure at socket creation time

From: Greg Kroah-Hartman
Date: Thu Feb 21 2019 - 09:45:47 EST

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


[ 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: Sasha Levin <sashal@xxxxxxxxxx>
net/vmw_vsock/vmci_transport.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index c361ce7824123..c3d5ab01fba7b 100644
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -1651,6 +1651,10 @@ static void vmci_transport_cleanup(struct work_struct *work)

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;
/* Ensure that the detach callback doesn't use the sk/vsk
* we are about to destruct.