In the Linux kernel, the following vulnerability has been resolved:
HID: bpf: cast size to ssize_t when checking hid_bpf_hw_request
As reported by Sashiko:
If a transport driver encounters a hardware error and returns a negative
error code such as -EPIPE, ret is implicitly promoted to size_t when
compared against size. This causes the negative error code to evaluate
as a large positive number, making the (ret > size) condition true.
This silently converts the hardware error into a success return value
and copies the unmodified buffer back, which could leave BPF programs
operating on uninitialized or stale data.
Fix this by casting size into ssize_t to return the actual negative
error code.
