Overview
About vulnerability
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.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 7 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- linux @ 5.4.0 (+19 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| CentOS 7 ELS | Planned | — |
| Debian 12 | Planned | — |
| Debian 13 | Planned | — |