In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: HIDP: validate numbered report payloads
When hidp_get_raw_report() waits for a numbered report, hidp_process_data() compares the expected report number with skb->data[0]. A connected HIDP peer can reply with only a DATA transaction header, leaving the skb empty after the header is removed.
KMSAN reports an uninitialized-value use in hidp_session_run(), with the value originating in __alloc_skb() through vhci_write(). The transaction header checks remove the empty-frame reports, but this report remains until the payload check is added.
The comparison can also consume a peer-controlled byte beyond the declared L2CAP PDU. A DATA | FEATURE response followed by an extra 0x01 byte made the current code accept that byte as report ID 1 and complete HIDIOCGFEATURE with a zero-byte result. With this change the malformed response is rejected with -EIO, while a subsequent valid response still succeeds.
Require a payload byte before comparing a numbered report ID. Unnumbered reports continue to accept an empty payload.
References
- https://git.kernel.org/stable/c/27cc0e603355c585f1e5da8398faa4d36d498188
- https://git.kernel.org/stable/c/34f53d27b81a16a02828c8fdfa4e02badc326f17
- https://git.kernel.org/stable/c/7e7162427659b70ea17cd41b1f79e2e64c246690
- https://git.kernel.org/stable/c/9c841f59e10b5d75c398a3fc6b2da448d2a2276b
- https://git.kernel.org/stable/c/b7ad105d46acd828e424454815e4cd31069e047a