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HID: bpf: prevent the same struct_ops to be attached more than once

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If the struct_ops is already attached, we should bail out or we will
end up in various locks and pointer issues while unregistering.

Link: https://patch.msgid.link/20240723-fix-6-11-bpf-v1-3-b9d770346784@kernel.org
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
This commit is contained in:
Benjamin Tissoires 2024-07-23 18:21:53 +02:00
parent f64c1a4593
commit acd34cfc48
1 changed files with 5 additions and 0 deletions
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5
drivers/hid/bpf/hid_bpf_struct_ops.c
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@ -183,6 +183,10 @@ static int hid_bpf_reg(void *kdata, struct bpf_link *link)
struct hid_device *hdev;
int count, err = 0;
/* prevent multiple attach of the same struct_ops */
if (ops->hdev)
return -EINVAL;
hdev = hid_get_device(ops->hid_id);
if (IS_ERR(hdev))
return PTR_ERR(hdev);
@ -248,6 +252,7 @@ static void hid_bpf_unreg(void *kdata, struct bpf_link *link)
list_del_rcu(&ops->list);
synchronize_srcu(&hdev->bpf.srcu);
ops->hdev = NULL;
reconnect = hdev->bpf.rdesc_ops == ops;
if (reconnect)