CVE-2024-26796

drivers: perf: ctr_get_width function for legacy is not defined

Published Apr 4, 2024 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
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

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-476
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.8:rc6:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Weaknesses CWE-366
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 11, 2026, 8:04 PM
Reserved
Feb 19, 2024, 2:20 PM
Status
Analyzed
Published
Apr 4, 2024, 9:15 AM
Modified
Jun 17, 2026, 7:18 AM
Severity
Moderate
Public date
Apr 4, 2024, 12:00 AM