In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: validate connectionless PSM length
Connectionless L2CAP frames carry a two-byte PSM at the start of the
payload. l2cap_recv_frame() currently reads that PSM unconditionally
after validating only the outer L2CAP length.
A malformed connectionless frame with a zero- or one-byte payload can
therefore make the parser read beyond the advertised skb payload and use
tailroom bytes as part of the PSM. A VHCI-backed QEMU reproducer
injected a one-byte connectionless payload and reached the unchecked
read.
Reject connectionless frames that cannot contain the PSM before reading
or pulling it. This preserves all valid connectionless frames while
dropping only structurally incomplete packets.
Bluetooth: L2CAP: validate connectionless PSM length
Connectionless L2CAP frames carry a two-byte PSM at the start of the
payload. l2cap_recv_frame() currently reads that PSM unconditionally
after validating only the outer L2CAP length.
A malformed connectionless frame with a zero- or one-byte payload can
therefore make the parser read beyond the advertised skb payload and use
tailroom bytes as part of the PSM. A VHCI-backed QEMU reproducer
injected a one-byte connectionless payload and reached the unchecked
read.
Reject connectionless frames that cannot contain the PSM before reading
or pulling it. This preserves all valid connectionless frames while
dropping only structurally incomplete packets.
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Thu, 24 Sep 2026 16:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: validate connectionless PSM length Connectionless L2CAP frames carry a two-byte PSM at the start of the payload. l2cap_recv_frame() currently reads that PSM unconditionally after validating only the outer L2CAP length. A malformed connectionless frame with a zero- or one-byte payload can therefore make the parser read beyond the advertised skb payload and use tailroom bytes as part of the PSM. A VHCI-backed QEMU reproducer injected a one-byte connectionless payload and reached the unchecked read. Reject connectionless frames that cannot contain the PSM before reading or pulling it. This preserves all valid connectionless frames while dropping only structurally incomplete packets. | |
| Title | Bluetooth: L2CAP: validate connectionless PSM length | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-09-24T16:03:15.141Z
Reserved: 2026-09-24T14:53:16.866Z
Link: CVE-2026-97408
No data.
Status : Received
Published: 2026-09-24T17:17:18.337
Modified: 2026-09-24T17:17:18.337
Link: CVE-2026-97408
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.