UBUNTU-CVE-2026-98037: Medium severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: bpf: Reject untrusted allocated-object pointers When the final RCU read-side critical section ends, a local kptr is demoted to PTRUNTRUSTED but retains MEMALLOC. The pointer may be NULL or may refer to an object whose lifetime is no longer protected. typeisptrallocobj() nevertheless recognizes any PTRTOBTFID with MEMALLOC as a live allocated object. In particular, a refcount-only local kptr never carries NONOWNREF, so it still passes the bpfrefcountacquire() argument check after RCU protection ends. The kfunc can then dereference NULL or stale memory. Make typeisptrallocobj() reject PTRUNTRUSTED pointers. Since typeisnonowningref() is based on the same predicate, graph kfunc arguments obey the same live-object requirement. Fault-protected reads of the demoted pointer remain valid: writes are already rejected, and read fixups use bpfmayfaultonderef() rather than this predicate. [ kkd: Rewrote commit log ]
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
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ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
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ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1