UBUNTU-CVE-2026-98816: Medium severity ubuntu/linux-aws vulnerability
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix overflow of jump offset in constant blinding bpfjitblindinsn() rewrites 'if rX op imm goto off' into: AX = imm ^ rnd AX ^= rnd if rX op AX goto off and subtracts 2 from off when the jump is backward. off is s16, so -32767 and -32768 wrap and the jump goes 32767 insns forward, past the end of the prog. The jump is inside the patch, hence bpfadjbranches() doesn't check it. The kernel crashes when such prog runs with bpfjitharden=2. Return -ERANGE in such case. bpfjitblindconstants() fails the same way when blinding of other insns moves a jump out of range.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.18~24.04.1 - Upgrade
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ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1019.19~24.04.1 - Upgrade
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ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.19~24.04.1 - Upgrade
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ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1016.18~24.04.1 - Upgrade
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-43.43.1~24.04.2 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-43.43 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1017.18 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1020.21 - Upgrade
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ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1019.19 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1017.19 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1010.11 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1018.18 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1018.18 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-43.43.1
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
The issue affects the listed Ubuntu Linux kernel packages, including standard, AWS, Azure, GCP, FIPS, AWS FIPS, Azure FIPS, and GCP FIPS variants. Exploitation requires BPF JIT constant blinding to be enabled with bpf_jit_harden=2.
What level of access does an attacker need?
An attacker needs high privileges and local access to load and run a crafted BPF program. No user interaction is required.
What is the likely impact of successful exploitation?
A crafted program can cause an out-of-range jump during JIT constant blinding and crash the kernel when the program runs. The provided impact data indicates availability impact only, with no stated confidentiality or integrity impact.
What can be done if an updated kernel cannot be installed immediately?
Avoid running with bpf_jit_harden=2 until a fixed kernel is available. Restrict access to privileged users who can load and execute BPF programs.