CVE-2023-53557

low-risk

Published 2025-10-04

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.

Do I need to act?

0.01% chance of exploitation

EPSS score — low exploit probability

Not on CISA KEV list

No confirmed active exploitation reported to CISA

Patch status unknown

Check vendor advisories for fix availability and mitigation guidance

CVSS 5.5/10 Medium

LOCAL / LOW complexity

Affected Products (2)

Linux Kernel

Affected Vendors

Linux

References (3)

Patch https://git.kernel.org/stable/c/03d63255a5783243c110aec5e6ae2f1475c3be76

Patch https://git.kernel.org/stable/c/5f81018753dfd4989e33ece1f0cb6b8aae498b82

Patch https://git.kernel.org/stable/c/ce3ec57faff559ccae1e0150c1f077eb2df648a4

/ 100

low-risk

Severity 18/34 · Moderate

Exploitability 0/34 · Minimal

Exposure 7/34 · Low