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CVE PROGRAM SOURCE RECORD7.7 High

CVE-2026-46123

Bluetooth: virtio_bt: clamp rx length before skb_put

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Status
Published
Published
Updated
Assigning organization
Linux

Description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: virtio_bt: clamp rx length before skb_put virtbt_rx_work() calls skb_put(skb, len) where len comes directly from virtqueue_get_buf() with no validation against the buffer we posted to the device. The RX skb is allocated in virtbt_add_inbuf() and exposed to virtio as exactly 1000 bytes via sg_init_one(). Checking len against skb_tailroom(skb) is not sufficient because alloc_skb() can leave more tailroom than the 1000 bytes actually handed to the device. A malicious or buggy backend can therefore report used.len between 1001 and skb_tailroom(skb), causing skb_put() to include uninitialized kernel heap bytes that were never written by the device. The same path also accepts len == 0, in which case skb_put(skb, 0) leaves the skb empty but virtbt_rx_handle() still reads the pkt_type byte from skb->data, consuming uninitialized memory. Define VIRTBT_RX_BUF_SIZE once and reuse it in alloc_skb() and sg_init_one(), and gate virtbt_rx_work() on that same constant so the bound checked matches the buffer actually exposed to the device. Reject used.len == 0 in the same gate so an empty completion can no longer reach virtbt_rx_handle(). Use bt_dev_err_ratelimited() because the length value comes from an untrusted backend that can otherwise flood the kernel log. Same class of bug as commit c04db81cd028 ("net/9p: Fix buffer overflow in USB transport layer"), which hardened the USB 9p transport against unchecked device-reported length.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • cf2719a21fdb9d4c8e9c834d279163609bef575d to < 4236e55b2d9d1ffd3b4bdf8ebbb86e5a0a526b4aaffected
  • 160fbcf3bfb93c3c086427f9f4c8bc70f217e9be to < fd91fa2678ab603dfb285416c1cf3843d7be1e41affected
  • 160fbcf3bfb93c3c086427f9f4c8bc70f217e9be to < ed41c81d30b211a671667259c3b5feeba0e062d5affected
  • 160fbcf3bfb93c3c086427f9f4c8bc70f217e9be to < 6c1730099a6fc18b183bd6c1adad3b54adcaeda9affected
  • 160fbcf3bfb93c3c086427f9f4c8bc70f217e9be to < b40cdd1b1370d76e9e760af4490cb4a351cceeadaffected
  • 160fbcf3bfb93c3c086427f9f4c8bc70f217e9be to < e6b4296f170d949ebba937cf6a3f247ec9550d2caffected
  • 160fbcf3bfb93c3c086427f9f4c8bc70f217e9be to < 21bd244b6de5d2fe1063c23acc93fbdd2b20d112affected
  • 9b67438e315b925a699f0178f4a48baf3d2d6ef4affected
  • 5.15.78 to < 5.15.209affected
  • 6.0.8 to < 6.1affected

Linux Linux

Default version status: affected

  • 6.1affected
  • 0 to < 6.1unaffected
  • 5.15.209 to ≤ 5.15.*unaffected
  • 6.1.175 to ≤ 6.1.*unaffected
  • 6.6.140 to ≤ 6.6.*unaffected
  • 6.12.88 to ≤ 6.12.*unaffected
  • 6.18.30 to ≤ 6.18.*unaffected
  • 7.0.7 to ≤ 7.0.*unaffected
  • 7.1 to ≤ *unaffected

References