CVE-2023-53557

fprobe: Release rethook after the ftrace_ops is unregistered

MEDIUM
5.5
CVSS Score
Published: October 4, 2025 at 03:17 PM UTC
Updated: October 15, 2026 at 10:17 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.18 ≤ v < 6.1.406.2 ≤ v < 6.4.55b0ab78998e32564a011b14c4c7f9c81e2d42b9d6.56.5 rc1
Vendor states this is fixed in 03d63255a5783243c110aec5e6ae2f1475c3be76 (fixed)
Vendor states this is fixed in 5f81018753dfd4989e33ece1f0cb6b8aae498b82 (fixed)
Vendor states this is fixed in ce3ec57faff559ccae1e0150c1f077eb2df648a4 (fixed)
Vendor states this is fixed in 5.18 (unaffected)
Vendor states this is fixed in 6.1.40 (unaffected)
Vendor states this is fixed in 6.4.5 (unaffected)
Vendor states this is fixed in 6.5 (unaffected)

SSVC — Action Prioritization

SSVCNo known exploitNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
NVD-CWE-noinfo

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