__vsock_net_mode_string() returns success without updating new_mode when
the write length is zero. Its caller then reads the uninitialized enum and
may permanently store a stack-derived value in the write-once child mode.
Initialize new_mode from the current child mode so that an empty write is
a no-op.
Fixes: eafb64f40ca4 ("vsock: add netns to vsock core")
Cc: [email protected]
Signed-off-by: Aldo Ariel Panzardo <[email protected]>
---
net/vmw_vsock/af_vsock.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 622dbd0467..61163357ae 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -2878,6 +2878,7 @@ static int vsock_net_child_mode_string(const struct
ctl_table *table, int write,
int ret;
net = container_of(table->data, struct net, vsock.child_ns_mode);
+ new_mode = vsock_net_child_mode(net);
ret = __vsock_net_mode_string(table, write, buffer, lenp, ppos,
vsock_net_child_mode(net), &new_mode);
--
2.43.0
