CVE-2025-40122
published 2025-11-12CVE-2025-40122: In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error When running perf_fuzzer on PTL…
PriorityP423medium4.7
EPSS
0.18%
7.8th percentile
In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
When running perf_fuzzer on PTL, sometimes the below "unchecked MSR
access error" is seen when accessing IA32_PMC_x_CFG_B MSRs.
[ 55.611268] unchecked MSR access error: WRMSR to 0x1986 (tried to write 0x0000000200000001) at rIP: 0xffffffffac564b28 (native_write_msr+0x8/0x30)
[ 55.611280] Call Trace:
[ 55.611282]
[ 55.611284] ? intel_pmu_config_acr+0x87/0x160
[ 55.611289] intel_pmu_enable_acr+0x6d/0x80
[ 55.611291] intel_pmu_enable_event+0xce/0x460
[ 55.611293] x86_pmu_start+0x78/0xb0
[ 55.611297] x86_pmu_enable+0x218/0x3a0
[ 55.611300] ? x86_pmu_enable+0x121/0x3a0
[ 55.611302] perf_pmu_enable+0x40/0x50
[ 55.611307] ctx_resched+0x19d/0x220
[ 55.611309] __perf_install_in_context+0x284/0x2f0
[ 55.611311] ? __pfx_remote_function+0x10/0x10
[ 55.611314] remote_function+0x52/0x70
[ 55.611317] ? __pfx_remote_function+0x10/0x10
[ 55.611319] generic_exec_single+0x84/0x150
[ 55.611323] smp_call_function_single+0xc5/0x1a0
[ 55.611326] ? __pfx_remote_function+0x10/0x10
[ 55.611329] perf_install_in_context+0xd1/0x1e0
[ 55.611331] ? __pfx___perf_install_in_context+0x10/0x10
[ 55.611333] __do_sys_perf_event_open+0xa76/0x1040
[ 55.611336] __x64_sys_perf_event_open+0x26/0x30
[ 55.611337] x64_sys_call+0x1d8e/0x20c0
[ 55.611339] do_syscall_64+0x4f/0x120
[ 55.611343] entry_SYSCALL_64_after_hwframe+0x76/0x7e
On PTL, GP counter 0 and 1 doesn't support auto counter reload feature,
thus it would trigger a #GP when trying to write 1 on bit 0 of CFG_B MSR
which requires to enable auto counter reload on GP counter 0.
The root cause of causing this issue is the check for auto counter
reload (ACR) counter mask from user space is incorrect in
intel_pmu_acr_late_setup() helper. It leads to an invalid ACR counter
mask from user space could be set into hw.config1 and then written into
CFG_B MSRs and trigger the MSR access warning.
e.g., User may create a perf event with AC
Affected
9 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | linux | < linux 6.17.6-1 (forky) | linux 6.17.6-1 (forky) |
| linux | linux | — | — |
| linux | linux | >= ec980e4facef8110f6fce27e5b6344660117f01f < c6cca4213b618c92e4972919ee568f0fb87313b1 | c6cca4213b618c92e4972919ee568f0fb87313b1 |
| linux | linux | >= ec980e4facef8110f6fce27e5b6344660117f01f < 43796f30507802d93ead2dc44fc9637f34671a89 | 43796f30507802d93ead2dc44fc9637f34671a89 |
| linux | linux_kernel | >= 0 < 6.17.6-1 | 6.17.6-1 |
| linux | linux_kernel | >= 0 < 6.17.0-14.14 | 6.17.0-14.14 |
| linux | linux_kernel | >= 6.16.0 < 6.17.3 | 6.17.3 |
| ubuntu | linux-aws | — | — |
| ubuntu | linux-oracle | — | — |
Stop checking back — get the weekly exploitation signal.
Every Monday: what got weaponized or added to CISA KEV in the last seven days — each CVE cross-linked to its PoC, Nuclei template, and detection rule. Free, one email a week, unsubscribe in one click.
OSV
linux-azure vulnerabilities
osv·2026-02-24
linux-azure vulnerabilities
linux-azure vulnerabilities
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- MIPS architecture;
- Nios II architecture;
- PA-RISC architecture;
- RISC-V architecture;
- S390 architecture;
- Sun Sparc architecture;
- x86 architecture;
- Xtensa architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- ACPI drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Bus devices;
- Hardware random number generator core;
- Character device driver;
- Clock framework and drivers;
- Data acquisition framework and drivers;
- CPU frequency scaling framework;
- Hardware crypto device drivers
OSV
linux-oem-6.17 vulnerabilities
osv·2026-02-17
linux-oem-6.17 vulnerabilities
linux-oem-6.17 vulnerabilities
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- MIPS architecture;
- Nios II architecture;
- PA-RISC architecture;
- RISC-V architecture;
- S390 architecture;
- Sun Sparc architecture;
- x86 architecture;
- Xtensa architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- ACPI drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Bus devices;
- Hardware random number generator core;
- Character device driver;
- Clock framework and drivers;
- Data acquisition framework and drivers;
- CPU frequency scaling framework;
- Hardware crypto device driv
OSV
linux-aws, linux-oracle vulnerabilities
osv·2026-02-17
linux-aws, linux-oracle vulnerabilities
linux-aws, linux-oracle vulnerabilities
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- MIPS architecture;
- Nios II architecture;
- PA-RISC architecture;
- RISC-V architecture;
- S390 architecture;
- Sun Sparc architecture;
- x86 architecture;
- Xtensa architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- ACPI drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Bus devices;
- Hardware random number generator core;
- Character device driver;
- Clock framework and drivers;
- Data acquisition framework and drivers;
- CPU frequency scaling framework;
- Hardware crypto de
OSV
linux-gcp vulnerabilities
osv·2026-02-12
linux-gcp vulnerabilities
linux-gcp vulnerabilities
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- MIPS architecture;
- Nios II architecture;
- PA-RISC architecture;
- RISC-V architecture;
- S390 architecture;
- Sun Sparc architecture;
- x86 architecture;
- Xtensa architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- ACPI drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Bus devices;
- Hardware random number generator core;
- Character device driver;
- Clock framework and drivers;
- Data acquisition framework and drivers;
- CPU frequency scaling framework;
- Hardware crypto device drivers;
OSV
linux, linux-raspi, linux-realtime vulnerabilities
osv·2026-02-12
linux, linux-raspi, linux-realtime vulnerabilities
linux, linux-raspi, linux-realtime vulnerabilities
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- MIPS architecture;
- Nios II architecture;
- PA-RISC architecture;
- RISC-V architecture;
- S390 architecture;
- Sun Sparc architecture;
- x86 architecture;
- Xtensa architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- ACPI drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Bus devices;
- Hardware random number generator core;
- Character device driver;
- Clock framework and drivers;
- Data acquisition framework and drivers;
- CPU frequency scaling framework;
- Hardwar
OSV
CVE-2025-40122: In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error When running perf_fuzzer on
osv·2025-11-12
CVE-2025-40122 CVE-2025-40122: In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error When running perf_fuzzer on
In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error When running perf_fuzzer on PTL, sometimes the below "unchecked MSR access error" is seen when accessing IA32_PMC_x_CFG_B MSRs. [ 55.611268] unchecked MSR access error: WRMSR to 0x1986 (tried to write 0x0000000200000001) at rIP: 0xffffffffac564b28 (native_write_msr+0x8/0x30) [ 55.611280] Call Trace: [ 55.611282] [ 55.611284] ? intel_pmu_config_acr+0x87/0x160 [ 55.611289] intel_pmu_enable_acr+0x6d/0x80 [ 55.611291] intel_pmu_enable_event+0xce/0x460 [ 55.611293] x86_pmu_start+0x78/0xb0 [ 55.611297] x86_pmu_enable+0x218/0x3a0 [ 55.611300] ? x86_pmu_enable+0x121/0x3a0 [ 55.611302] perf_pmu_enable+0x40/0x50 [ 55.611307] ctx_resched+0x19d/0x220 [ 55.611309] __perf_install_in
GHSA
GHSA-pp9f-hhc8-x68x: In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
When running perf_fuzzer
ghsa_unreviewed·2025-11-12
CVE-2025-40122 GHSA-pp9f-hhc8-x68x: In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
When running perf_fuzzer
In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
When running perf_fuzzer on PTL, sometimes the below "unchecked MSR
access error" is seen when accessing IA32_PMC_x_CFG_B MSRs.
[ 55.611268] unchecked MSR access error: WRMSR to 0x1986 (tried to write 0x0000000200000001) at rIP: 0xffffffffac564b28 (native_write_msr+0x8/0x30)
[ 55.611280] Call Trace:
[ 55.611282]
[ 55.611284] ? intel_pmu_config_acr+0x87/0x160
[ 55.611289] intel_pmu_enable_acr+0x6d/0x80
[ 55.611291] intel_pmu_enable_event+0xce/0x460
[ 55.611293] x86_pmu_start+0x78/0xb0
[ 55.611297] x86_pmu_enable+0x218/0x3a0
[ 55.611300] ? x86_pmu_enable+0x121/0x3a0
[ 55.611302] perf_pmu_enable+0x40/0x50
[ 55.611307] ctx_resched+0x19d/0x220
[ 55.611309] __perf_install
OSV
perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
osv·2025-11-12
CVE-2025-40122 perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
When running perf_fuzzer on PTL, sometimes the below "unchecked MSR
access error" is seen when accessing IA32_PMC_x_CFG_B MSRs.
[ 55.611268] unchecked MSR access error: WRMSR to 0x1986 (tried to write 0x0000000200000001) at rIP: 0xffffffffac564b28 (native_write_msr+0x8/0x30)
[ 55.611280] Call Trace:
[ 55.611282]
[ 55.611284] ? intel_pmu_config_acr+0x87/0x160
[ 55.611289] intel_pmu_enable_acr+0x6d/0x80
[ 55.611291] intel_pmu_enable_event+0xce/0x460
[ 55.611293] x86_pmu_start+0x78/0xb0
[ 55.611297] x86_pmu_enable+0x218/0x3a0
[ 55.611300] ? x86_pmu_enable+0x121/0x3a0
[ 55.611302] perf_pmu_enable+0x40/0x50
[ 55.611
Ubuntu
Linux kernel (Azure) vulnerabilities
vendor_ubuntu·2026-02-24
CVE-2025-40175 Linux kernel (Azure) vulnerabilities
Title: Linux kernel (Azure) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- MIPS architecture;
- Nios II architecture;
- PA-RISC architecture;
- RISC-V architecture;
- S390 architecture;
- Sun Sparc architecture;
- x86 architecture;
- Xtensa architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- ACPI drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Bus devices;
- Hardware random number generator core;
- Character device driver;
- Clock framework and drivers;
- Data acquisition framewor
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-02-17
CVE-2025-40304 Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- MIPS architecture;
- Nios II architecture;
- PA-RISC architecture;
- RISC-V architecture;
- S390 architecture;
- Sun Sparc architecture;
- x86 architecture;
- Xtensa architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- ACPI drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Bus devices;
- Hardware random number generator core;
- Character device driver;
- Clock framework and drivers;
- Data acquisition framework and dr
Ubuntu
Linux kernel (OEM) vulnerabilities
vendor_ubuntu·2026-02-17
CVE-2025-68242 Linux kernel (OEM) vulnerabilities
Title: Linux kernel (OEM) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- MIPS architecture;
- Nios II architecture;
- PA-RISC architecture;
- RISC-V architecture;
- S390 architecture;
- Sun Sparc architecture;
- x86 architecture;
- Xtensa architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- ACPI drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Bus devices;
- Hardware random number generator core;
- Character device driver;
- Clock framework and drivers;
- Data acquisition framework
Ubuntu
Linux kernel (GCP) vulnerabilities
vendor_ubuntu·2026-02-12
CVE-2025-68242 Linux kernel (GCP) vulnerabilities
Title: Linux kernel (GCP) vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- MIPS architecture;
- Nios II architecture;
- PA-RISC architecture;
- RISC-V architecture;
- S390 architecture;
- Sun Sparc architecture;
- x86 architecture;
- Xtensa architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- ACPI drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Bus devices;
- Hardware random number generator core;
- Character device driver;
- Clock framework and drivers;
- Data acquisition framework
Ubuntu
Linux kernel vulnerabilities
vendor_ubuntu·2026-02-12
CVE-2025-40304 Linux kernel vulnerabilities
Title: Linux kernel vulnerabilities
Summary: Several security issues were fixed in the Linux kernel.
Several security issues were discovered in the Linux kernel.
An attacker could possibly use these to compromise the system.
This update corrects flaws in the following subsystems:
- ARM64 architecture;
- MIPS architecture;
- Nios II architecture;
- PA-RISC architecture;
- RISC-V architecture;
- S390 architecture;
- Sun Sparc architecture;
- x86 architecture;
- Xtensa architecture;
- Block layer subsystem;
- Cryptographic API;
- Compute Acceleration Framework;
- ACPI drivers;
- Drivers core;
- Network block device driver;
- Bluetooth drivers;
- Bus devices;
- Hardware random number generator core;
- Character device driver;
- Clock framework and drivers;
- Data acquisition framework and dr
Red Hat
kernel: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
vendor_redhat·2025-11-12·CVSS 4.7
CVE-2025-40122 [MEDIUM] CWE-20 kernel: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
kernel: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
In the Linux kernel, the following vulnerability has been resolved:
perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error
When running perf_fuzzer on PTL, sometimes the below "unchecked MSR
access error" is seen when accessing IA32_PMC_x_CFG_B MSRs.
[ 55.611268] unchecked MSR access error: WRMSR to 0x1986 (tried to write 0x0000000200000001) at rIP: 0xffffffffac564b28 (native_write_msr+0x8/0x30)
[ 55.611280] Call Trace:
[ 55.611282]
[ 55.611284] ? intel_pmu_config_acr+0x87/0x160
[ 55.611289] intel_pmu_enable_acr+0x6d/0x80
[ 55.611291] intel_pmu_enable_event+0xce/0x460
[ 55.611293] x86_pmu_start+0x78/0xb0
[ 55.611297] x86_pmu_enable+0x218/0x3a0
[ 55.611300] ? x86_pmu_enable+0x121/0x3a0
[ 55.611302] perf_pmu_enable+0x40/0x50
[ 5
Debian
CVE-2025-40122: linux - In the Linux kernel, the following vulnerability has been resolved: perf/x86/in...
vendor_debian·2025
CVE-2025-40122 [LOW] CVE-2025-40122: linux - In the Linux kernel, the following vulnerability has been resolved: perf/x86/in...
In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Fix IA32_PMC_x_CFG_B MSRs access error When running perf_fuzzer on PTL, sometimes the below "unchecked MSR access error" is seen when accessing IA32_PMC_x_CFG_B MSRs. [ 55.611268] unchecked MSR access error: WRMSR to 0x1986 (tried to write 0x0000000200000001) at rIP: 0xffffffffac564b28 (native_write_msr+0x8/0x30) [ 55.611280] Call Trace: [ 55.611282] [ 55.611284] ? intel_pmu_config_acr+0x87/0x160 [ 55.611289] intel_pmu_enable_acr+0x6d/0x80 [ 55.611291] intel_pmu_enable_event+0xce/0x460 [ 55.611293] x86_pmu_start+0x78/0xb0 [ 55.611297] x86_pmu_enable+0x218/0x3a0 [ 55.611300] ? x86_pmu_enable+0x121/0x3a0 [ 55.611302] perf_pmu_enable+0x40/0x50 [ 55.611307] ctx_resched+0x19d/0x220 [ 55.611309] __perf_install_in
No detection rules found.
No public exploits indexed.
2025-11-12
Published