Answer in brief
CVE-2026-64070 records a Medium severity (CVSS 5.5) vulnerability in powerpc/hv-gpci: fix preempt count leak in sysfs show paths. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=71f1c39647d8c9d4d54a861ec81f1ff17544bcb6 <b300312562fd6e4729697adb9f777f00ca0429f3 || >=71f1c39647d8c9d4d54a861ec81f1ff17544bcb6 <45afabe7f99c5d8746434ee41c86584c01d70147 || >=71f1c39647d8c9d4d54a861ec81f1ff17544bcb6 <b61ebb2826ca1852c2bbd92a676fb622c358cab4 || >=71f1c39647d8c9d4d54a861ec81f1ff17544bcb6 <903409000a07ac8e31ffedeb8516f4f8d67150c8 || >=71f1c39647d8c9d4d54a861ec81f1ff17544bcb6 <dbc30a57bd8e026995e9fa8e8c31cffd18542c01 | b300312562fd6e4729697adb9f777f00ca0429f3, 45afabe7f99c5d8746434ee41c86584c01d70147, b61ebb2826ca1852c2bbd92a676fb622c358cab4, 903409000a07ac8e31ffedeb8516f4f8d67150c8, dbc30a57bd8e026995e9fa8e8c31cffd18542c01 |
| Linux/Linuxgeneric | 6.6 | Not reported |
Published upstream
Jul 19, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 3, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 2, 2026
In the Linux kernel, the following vulnerability has been resolved: powerpc/hv-gpci: fix preempt count leak in sysfs show paths Four sysfs show() callbacks in hv-gpci take get_cpu_var(hv_gpci_reqb) (which calls preempt_disable()) but only call the matching put_cpu_var() on the error path under the 'out:' label. Every successful read leaks one preempt_disable(): processor_bus_topology_show() processor_config_show() affinity_domain_via_virtual_processor_show() affinity_domain_via_domain_show() (affinity_domain_via_partition_show() was already correct.) On a CONFIG_PREEMPT=y kernel, repeated reads raise preempt_count and eventually return to userspace with preemption still disabled. The next user-mode page fault then hits faulthandler_disabled() == 1, gets forced to SIGSEGV, and the resulting coredump trips 'BUG: scheduling while atomic' in call_usermodehelper_exec -> wait_for_completion_state -> schedule: BUG: scheduling while atomic: <task>/<pid>/0x00000004 ... __schedule_bug+0x6c/0x90 __schedule+0x58c/0x13a0 schedule+0x48/0x1a0 schedule_timeout+0x104/0x170 wait_for_completion_state+0x16c/0x330 call_usermodehelper_exec+0x254/0x2d0 vfs_coredump+0x1050/0x2590 get_signal+0xb9c/0xc80 do_notify_resume+0xf8/0x470 Add an out_success label that calls put_cpu_var() before returning the byte count, mirroring affinity_domain_via_partition_show().
Quoted source text, attributed separately from HOL analysis.