CVE-2026-46186
Description
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: virtio_bt: validate rx pkt_type header length virtbt_rx_handle() reads the leading pkt_type byte from the RX skb and forwards the remainder to hci_recv_frame() for every event/ACL/SCO/ISO type, without checking that the remaining payload is at least the fixed HCI header for that type. After the preceding patch bounds the backend-supplied used.len to [1, VIRTBT_RX_BUF_SIZE], a one-byte completion still reaches hci_recv_frame() with skb->len already pulled to 0. If the byte happened to be HCI_ACLDATA_PKT, the ACL-vs-ISO classification fast-path in hci_dev_classify_pkt_type() dereferences hci_acl_hdr(skb)->handle whenever the HCI device has an active CIS_LINK, BIS_LINK, or PA_LINK connection, reading two bytes of uninitialized RX-buffer data. The same hazard exists for every packet type the driver accepts because none of the switch cases in virtbt_rx_handle() check skb->len against the per-type minimum HCI header size before handing the frame to the core. After stripping pkt_type, require skb->len to cover the fixed header size for the selected type (event 2, ACL 4, SCO 3, ISO 4) before calling hci_recv_frame(); drop ratelimited otherwise. Unknown pkt_type values still take the original kfree_skb() default path. Use bt_dev_err_ratelimited() because both the length and pkt_type values come from an untrusted backend that can otherwise flood the kernel log.
CVSS Details
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Threat Intelligence
Weaknesses 1
Affected Products 15
| Vendor | Product | Version | Range |
|---|---|---|---|
| linux | linux_kernel | * | ≥5.15.78 – <5.15.209 |
| linux | linux_kernel | * | ≥6.0.8 – <6.1 |
| linux | linux_kernel | * | ≥6.1.1 – <6.1.175 |
| linux | linux_kernel | * | ≥6.2 – <6.6.140 |
| linux | linux_kernel | * | ≥6.7 – <6.12.88 |
| linux | linux_kernel | * | ≥6.13 – <6.18.30 |
| linux | linux_kernel | * | ≥6.19 – <7.0.7 |
| linux | linux_kernel | 6.1 | any |
| linux | linux_kernel | 6.1 | any |
| linux | linux_kernel | 6.1 | any |
| linux | linux_kernel | 6.1 | any |
| linux | linux_kernel | 6.1 | any |
| linux | linux_kernel | 6.1 | any |
| linux | linux_kernel | 7.1 | any |
| linux | linux_kernel | 7.1 | any |
References 7
- git.kernel.org https://git.kernel.org/stable/c/149cfb42ad69c7964fd9f2c43831da9152007129
- git.kernel.org https://git.kernel.org/stable/c/1e1e509b6fd2a42421745bbcd98bd16daad20904
- git.kernel.org https://git.kernel.org/stable/c/2c1143564c71e7497b42d8360a8379ccbb011d3c
- git.kernel.org https://git.kernel.org/stable/c/3485c7236c59c8c34a41af1c4b52982437554e79
- git.kernel.org https://git.kernel.org/stable/c/7b2d4c04816cdc887f472caaf7fc966cfc107e40
- git.kernel.org https://git.kernel.org/stable/c/daf23014e5d975e72ea9c02b5160d3fcf070ea47
- git.kernel.org https://git.kernel.org/stable/c/f743eab6486965f276c7e3f1700895f014fdc6db
Remediation
- git.kernel.org https://git.kernel.org/stable/c/149cfb42ad69c7964fd9f2c43831da9152007129
- git.kernel.org https://git.kernel.org/stable/c/1e1e509b6fd2a42421745bbcd98bd16daad20904
- git.kernel.org https://git.kernel.org/stable/c/2c1143564c71e7497b42d8360a8379ccbb011d3c
- git.kernel.org https://git.kernel.org/stable/c/3485c7236c59c8c34a41af1c4b52982437554e79
- git.kernel.org https://git.kernel.org/stable/c/7b2d4c04816cdc887f472caaf7fc966cfc107e40
- git.kernel.org https://git.kernel.org/stable/c/daf23014e5d975e72ea9c02b5160d3fcf070ea47
- git.kernel.org https://git.kernel.org/stable/c/f743eab6486965f276c7e3f1700895f014fdc6db