{"id":"AZL-88989","summary":"CVE-2026-46186 affecting package kernel for versions less than 6.6.141.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: virtio_bt: validate rx pkt_type header length\n\nvirtbt_rx_handle() reads the leading pkt_type byte from the RX skb\nand forwards the remainder to hci_recv_frame() for every\nevent/ACL/SCO/ISO type, without checking that the remaining payload\nis at least the fixed HCI header for that type.\n\nAfter the preceding patch bounds the backend-supplied used.len to\n[1, VIRTBT_RX_BUF_SIZE], a one-byte completion still reaches\nhci_recv_frame() with skb-\u003elen already pulled to 0. If the byte\nhappened to be HCI_ACLDATA_PKT, the ACL-vs-ISO classification\nfast-path in hci_dev_classify_pkt_type() dereferences\nhci_acl_hdr(skb)-\u003ehandle whenever the HCI device has an active\nCIS_LINK, BIS_LINK, or PA_LINK connection, reading two bytes of\nuninitialized RX-buffer data. The same hazard exists for every\npacket type the driver accepts because none of the switch cases in\nvirtbt_rx_handle() check skb-\u003elen against the per-type minimum HCI\nheader size before handing the frame to the core.\n\nAfter stripping pkt_type, require skb-\u003elen to cover the fixed\nheader size for the selected type (event 2, ACL 4, SCO 3, ISO 4)\nbefore calling hci_recv_frame(); drop ratelimited otherwise.\nUnknown pkt_type values still take the original kfree_skb() default\npath.\n\nUse bt_dev_err_ratelimited() because both the length and pkt_type\nvalues come from an untrusted backend that can otherwise flood the\nkernel log.","modified":"2026-08-28T17:46:35.793931171Z","published":"2026-05-28T10:16:34Z","upstream":["CVE-2026-46186"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46186"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.141.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-88989.json"}}],"schema_version":"1.9.0"}