UBUNTU-CVE-2026-92517: Medium severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: bpf, riscv: Fix extable handling for arena loadacquire emitatomicldst() returns 1 to have buildbody() skip the zext after a sub-word loadacquire. The caller does "ret = ret ?: addexceptionhandler(...)", which skips addexceptionhandler() on any non-zero ret, so the extable entry is missing and a faulting PROBEATOMIC loadacquire oopses. REGDONTCLEARMARKER leaves rd stale on fault, and the verifier still thinks the load overwrote it, so a program can leak it through a map. Check ret >= 0 before calling addexceptionhandler(), and pass rd for LOADACQ so the fault zeroes rd like a PROBEMEM load. Return ret unchanged for the zext skip.
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
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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
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1 - Compensating control
In the RISC-V BPF arena load-acquire extable handling, pass rd for LOAD_ACQ so a fault zeroes rd like a PROBE_MEM load; have emit_atomic_ld_st() return 1 so build_body() skips the sub-word load-acquire zext; return ret unchanged for the zext skip; and check ret >= 0 before calling add_exception_handler() so a faulting PROBE_ATOMIC load-acquire receives an extable entry.