CVE-2023-53557

fprobe: Release rethook after the ftrace_ops is unregistered

Published Oct 4, 2025 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

fprobe: Release rethook after the ftrace_ops is unregistered

While running bpf selftests it's possible to get following fault:

general protection fault, probably for non-canonical address \
0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI
...
Call Trace:
<TASK>
fprobe_handler+0xc1/0x270
? __pfx_bpf_testmod_init+0x10/0x10
? __pfx_bpf_testmod_init+0x10/0x10
? bpf_fentry_test1+0x5/0x10
? bpf_fentry_test1+0x5/0x10
? bpf_testmod_init+0x22/0x80
? do_one_initcall+0x63/0x2e0
? rcu_is_watching+0xd/0x40
? kmalloc_trace+0xaf/0xc0
? do_init_module+0x60/0x250
? __do_sys_finit_module+0xac/0x120
? do_syscall_64+0x37/0x90
? entry_SYSCALL_64_after_hwframe+0x72/0xdc
</TASK>

In unregister_fprobe function we can't release fp->rethook while it's
possible there are some of its users still running on another cpu.

Moving rethook_free call after fp->ops is unregistered with
unregister_ftrace_function call.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
EUVD EUVD EUVD-2023-60051 In the Linux kernel, the following vulnerability has been resolved: fprobe: Release rethook after the ftrace_ops is unregistered While running bpf selftests it's possible to get following fault: general protection fault, probably for non-canonical address \ 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI ... Call Trace: <TASK> fprobe_handler+0xc1/0x270 ? __pfx_bpf_testmod_init+0x10/0x10 ? __pfx_bpf_testmod_init+0x10/0x10 ? bpf_fentry_test1+0x5/0x10 ? bpf_fentry_test1+0x5/0x10 ? bpf_testmod_init+0x22/0x80 ? do_one_initcall+0x63/0x2e0 ? rcu_is_watching+0xd/0x40 ? kmalloc_trace+0xaf/0xc0 ? do_init_module+0x60/0x250 ? __do_sys_finit_module+0xac/0x120 ? do_syscall_64+0x37/0x90 ? entry_SYSCALL_64_after_hwframe+0x72/0xdc </TASK> In unregister_fprobe function we can't release fp->rethook while it's possible there are some of its users still running on another cpu. Moving rethook_free call after fp->ops is unregistered with unregister_ftrace_function call.
History
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.5:rc1:*:*:*:*:*:*
Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: fprobe: Release rethook after the ftrace_ops is unregistered While running bpf selftests it's possible to get following fault: general protection fault, probably for non-canonical address \ 0x6b6b6b6b6b6b6b6b: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI ... Call Trace: <TASK> fprobe_handler+0xc1/0x270 ? __pfx_bpf_testmod_init+0x10/0x10 ? __pfx_bpf_testmod_init+0x10/0x10 ? bpf_fentry_test1+0x5/0x10 ? bpf_fentry_test1+0x5/0x10 ? bpf_testmod_init+0x22/0x80 ? do_one_initcall+0x63/0x2e0 ? rcu_is_watching+0xd/0x40 ? kmalloc_trace+0xaf/0xc0 ? do_init_module+0x60/0x250 ? __do_sys_finit_module+0xac/0x120 ? do_syscall_64+0x37/0x90 ? entry_SYSCALL_64_after_hwframe+0x72/0xdc </TASK> In unregister_fprobe function we can't release fp->rethook while it's possible there are some of its users still running on another cpu. Moving rethook_free call after fp->ops is unregistered with unregister_ftrace_function call.
Title fprobe: Release rethook after the ftrace_ops is unregistered
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 15, 2026, 9:41 PM
Reserved
Oct 4, 2025, 3:14 PM
Status
Modified
Published
Oct 4, 2025, 4:15 PM
Modified
Oct 15, 2026, 10:17 PM
Severity
Low
Public date
Oct 4, 2025, 12:00 AM