UBUNTU-CVE-2026-98062: Medium severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: bpf: Mark signal tracepoint siginfo arguments as scalar The signalgenerate and signaldeliver tracepoints declare their info argument as a struct kernelsiginfo pointer. btfctxaccess() therefore treats it as a trusted pointer for tpbtf programs. Signal delivery also uses SENDSIGNOINFO and SENDSIGPRIV as special values for this argument. Those values are zero and one respectively, and are not pointers. A tpbtf program can currently dereference either value and fault the kernel. In particular, signalgenerate can run from timer interrupt context, turning the fault into a kernel panic. Record both tracepoints in rawtpnullargs[] and mark argument one as a non-pointer. This preserves scalar access to the cookie while rejecting direct and helper-mediated pointer use. Merely marking it nullable would not suffice because SENDSIGPRIV is nonzero.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1
Event History
Frequently Asked Questions
Which Ubuntu kernel packages are identified as affected?
The listed packages are ubuntu/linux-riscv, ubuntu/linux-realtime, ubuntu/linux-hwe-edge, ubuntu/linux-azure, ubuntu/linux-gcp, ubuntu/linux-azure-fde, ubuntu/linux-gke, and ubuntu/linux-aws-5.0.
What access does an attacker need to trigger the issue?
The vulnerability is rated as locally exploitable with low privileges and no user interaction required. Exploitation involves a tp_btf BPF program accessing the siginfo argument of the signal_generate or signal_deliver tracepoint as a pointer.
How could this lead to a system outage?
The tracepoint argument can contain the special values zero or one rather than a valid pointer. Dereferencing either can fault the kernel; because signal_generate can execute in timer interrupt context, the fault can cause a kernel panic.
How can I identify BPF programs that may be involved?
Look for tp_btf programs attached to the signal_generate or signal_deliver tracepoints that directly dereference the siginfo argument or pass it to helpers as a pointer. The corrected behavior permits scalar access to the cookie but rejects pointer-style use of that argument.