Hello Benjamin Tissoires,
Commit 4a86220e046d ("HID: bpf: remove tracing HID-BPF capability")
from Jun 8, 2024 (linux-next), leads to the following Smatch static
checker warning:
drivers/hid/bpf/hid_bpf_dispatch.c:65 dispatch_hid_bpf_device_event()
error: uninitialized symbol 'ret'.
drivers/hid/bpf/hid_bpf_dispatch.c
26 dispatch_hid_bpf_device_event(struct hid_device *hdev, enum hid_report_type type, u8 *data,
27 u32 *size, int interrupt)
28 {
29 struct hid_bpf_ctx_kern ctx_kern = {
30 .ctx = {
31 .hid = hdev,
32 .allocated_size = hdev->bpf.allocated_data,
33 .size = *size,
34 },
35 .data = hdev->bpf.device_data,
36 };
37 struct hid_bpf_ops *e;
38 int ret;
39
40 if (type >= HID_REPORT_TYPES)
41 return ERR_PTR(-EINVAL);
42
43 /* no program has been attached yet */
44 if (!hdev->bpf.device_data)
45 return data;
46
47 memset(ctx_kern.data, 0, hdev->bpf.allocated_data);
48 memcpy(ctx_kern.data, data, *size);
49
50 rcu_read_lock();
51 list_for_each_entry_rcu(e, &hdev->bpf.prog_list, list) {
52 if (e->hid_device_event) {
53 ret = e->hid_device_event(&ctx_kern.ctx, type);
54 if (ret < 0) {
55 rcu_read_unlock();
56 return ERR_PTR(ret);
57 }
58
59 if (ret)
60 ctx_kern.ctx.retval = ret;
61 }
Can all the e->hid_device_event pointers be NULL?
62 }
63 rcu_read_unlock();
64
65 if (ret) {
^^^
If so then ret is uninitialized
66 if (ret > ctx_kern.ctx.allocated_size)
67 return ERR_PTR(-EINVAL);
68
69 *size = ret;
regards,
dan carpenter
