drivers: perf: ctr_get_width function for legacy is not defined
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-476.
Summary
In the Linux kernel, the following vulnerability has been resolved: drivers: perf: ctr_get_width function for legacy is not defined With parameters CONFIG_RISCV_PMU_LEGACY=y and CONFIG_RISCV_PMU_SBI=n linux kernel crashes when you try perf record: $ perf record ls [ 46.749286] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000 [ 46.750199] Oops [#1] [ 46.750342] Modules linked in: [ 46.750608] CPU: 0 PID: 107 Comm: perf-exec Not tainted 6.6.0 #2 [ 46.750906] Hardware name: riscv-virtio,qemu (DT) [ 46.751184] epc : 0x0 [ 46.751430] ra : arch_perf_update_userpage+0x54/0x13e [ 46.751680] epc : 0000000000000000 ra : ffffffff8072ee52 sp : ff2000000022b8f0 [ 46.751958] gp : ffffffff81505988 tp : ff6000000290d400 t0 : ff2000000022b9c0 [ 46.752229] t1 : 0000000000000001 t2 : 0000000000000003 s0 : ff2000000022b930 [ 46.752451] s1 : ff600000028fb000 a0 : 0000000000000000 a1 : ff600000028fb000 [ 46.752673] a2 : 0000000ae2751268 a3 : 00000000004fb708 a4 : 0000000000000004 [ 46.752895] a5 : 0000000000000000 a6 : 000000000017ffe3 a7 : 00000000000000d2 [ 46.753117] s2 : ff600000028fb000 s3 : 0000000ae2751268 s4 : 0000000000000000 [ 46.753338] s5 : ffffffff8153e290 s6 : ff600000863b9000 s7 : ff60000002961078 [ 46.753562] s8 : ff60000002961048 s9 : ff60000002961058 s10: 0000000000000001 [ 46.753783] s11: 0000000000000018 t3 : ffffffffffffffff t4 : ffffffffffffffff [ 46.754005] t5 : ff6000000292270c t6 : ff2000000022bb30 [ 46.754179] status: 0000000200000100 badaddr: 0000000000000000 cause: 000000000000000c [ 46.754653] Code: Unable to access instruction at 0xffffffffffffffec. [ 46.754939] ---[ end trace 0000000000000000 ]--- [ 46.755131] note: perf-exec[107] exited with irqs disabled [ 46.755546] note: perf-exec[107] exited with preempt_count 4 This happens because in the legacy case the ctr_get_width function was not defined, but it is used in arch_perf_update_userpage. Also remove extra check in riscv_pmu_ctr_get_width_mask
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 6.6 and later | 6.6.21, 6.7.9, 6.8 | Patch available | CNA |
- Linux VendorLinux Affected 6.6 and later Fixed in 6.6.21, 6.7.9, 6.8 Patch available CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.6 to before 6.6.21; 6.7 to before 6.7.9 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:* | 6.8 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:* | 6.8 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:* | 6.8 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.8:rc4:*:*:*:*:*:* | 6.8 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.8:rc5:*:*:*:*:*:* | 6.8 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.8:rc6:*:*:*:*:*:* | 6.8 rc6 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 6.6 to before 6.6.21; 6.7 to before 6.7.9 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:* Versions 6.8 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:* Versions 6.8 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:* Versions 6.8 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.8:rc4:*:*:*:*:*:* Versions 6.8 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.8:rc5:*:*:*:*:*:* Versions 6.8 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.8:rc6:*:*:*:*:*:* Versions 6.8 rc6 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.6.21, 6.7.9, 6.8
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
Not affected: 4 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2024-26796
- 2026-10-03 Alias added: GHSA-x4pp-356g-v2qr
References
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2024-26796 · CVE Program
- CVE-2024-26796 · NVD
- FIRST EPSS
- GHSA-x4pp-356g-v2qr · GitHub Advisory Database · CC BY 4.0
- CVE-2024-26796 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences