UBUNTU-CVE-2025-22094
In the Linux kernel, the following vulnerability has been resolved: powerpc/perf: Fix ref-counting on the PMU 'vpa_pmu' Commit 176cda0619b6 ("powerpc/perf: Add perf interface to expose vpa counters") introduced 'vpa_pmu' to expose Book3s-HV nested APIv2 provided L1<->L2 context switch latency counters to L1 user-space via perf-events. However the newly introduced PMU named 'vpa_pmu' doesn't assign ownership of the PMU to the module 'vpa_pmu'. Consequently the module 'vpa_pmu' can be unloaded while one of the perf-events are still active, which can lead to kernel oops and panic of the form below on a Pseries-LPAR: BUG: Kernel NULL pointer dereference on read at 0x00000058 <snip> NIP [c000000000506cb8] event_sched_out+0x40/0x258 LR [c00000000050e8a4] __perf_remove_from_context+0x7c/0x2b0 Call Trace: [c00000025fc3fc30] [c00000025f8457a8] 0xc00000025f8457a8 (unreliable) [c00000025fc3fc80] [fffffffffffffee0] 0xfffffffffffffee0 [c00000025fc3fcd0] [c000000000501e70] event_function+0xa8/0x120 <snip> Kernel panic - not syncing: Aiee, killing interrupt handler! Fix this by adding the module ownership to 'vpa_pmu' so that the module 'vpa_pmu' is ref-counted and prevented from being unloaded when perf-events are initialized.
02 / AFFECTED SOFTWARE
Affected packages
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37 explicit affected versions
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16 explicit affected versions
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13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
14 explicit affected versions
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11 explicit affected versions
7 explicit affected versions
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13 explicit affected versions
43 explicit affected versions
10 explicit affected versions
8 explicit affected versions
14 explicit affected versions
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78 explicit affected versions
11 explicit affected versions
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03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: powerpc/perf: Fix ref-counting on the PMU 'vpa_pmu' Commit 176cda0619b6 ("powerpc/perf: Add perf interface to expose vpa counters") introduced 'vpa_pmu' to expose Book3s-HV nested APIv2 provided L1<->L2 context switch latency counters to L1 user-space via perf-events. However the newly introduced PMU named 'vpa_pmu' doesn't assign ownership of the PMU to the module 'vpa_pmu'. Consequently the module 'vpa_pmu' can be unloaded while one of the perf-events are still active, which can lead to kernel oops and panic of the form below on a Pseries-LPAR: BUG: Kernel NULL pointer dereference on read at 0x00000058 <snip> NIP [c000000000506cb8] event_sched_out+0x40/0x258 LR [c00000000050e8a4] __perf_remove_from_context+0x7c/0x2b0 Call Trace: [c00000025fc3fc30] [c00000025f8457a8] 0xc00000025f8457a8 (unreliable) [c00000025fc3fc80] [fffffffffffffee0] 0xfffffffffffffee0 [c00000025fc3fcd0] [c000000000501e70] event_function+0xa8/0x120 <snip> Kernel panic - not syncing: Aiee, killing interrupt handler! Fix this by adding the module ownership to 'vpa_pmu' so that the module 'vpa_pmu' is ref-counted and prevented from being unloaded when perf-events are initialized.
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/ff99d5b6a246715f2257123cdf6c4a29cb33aa78
- https://git.kernel.org/stable/c/6cf045b51e2c5721db7e55305f09ee32741e00f9
- https://git.kernel.org/stable/c/70ea7c5189197c6f5acdcfd8a2651be2c41e2faa
- https://git.kernel.org/stable/c/ff99d5b6a246715f2257123cdf6c4a29cb33aa78
- https://ubuntu.com/security/CVE-2025-22094
- https://ubuntu.com/security/notices/USN-7594-1
- https://ubuntu.com/security/notices/USN-7594-2
- https://ubuntu.com/security/notices/USN-7594-3
- https://www.cve.org/CVERecord?id=CVE-2025-22094