In the Linux kernel, the following vulnerability has been resolved:

bpf: Fix memleak due to fentry attach failure

If it fails to attach fentry, the allocated bpf trampoline image will be
left in the system. That can be verified by checking /proc/kallsyms.

This meamleak can be verified by a simple bpf program as follows:

SEC("fentry/trap_init")
int fentry_run()
{
return 0;
}

It will fail to attach trap_init because this function is freed after
kernel init, and then we can find the trampoline image is left in the
system by checking /proc/kallsyms.

$ tail /proc/kallsyms
ffffffffc0613000 t bpf_trampoline_6442453466_1 [bpf]
ffffffffc06c3000 t bpf_trampoline_6442453466_1 [bpf]

$ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "FUNC 'trap_init'"
[2522] FUNC 'trap_init' type_id=119 linkage=static

$ echo $((6442453466 & 0x7fffffff))
2522

Note that there are two left bpf trampoline images, that is because the
libbpf will fallback to raw tracepoint if -EINVAL is returned.
Advisories
Source ID Title
EUVD EUVD EUVD-2023-59863 In the Linux kernel, the following vulnerability has been resolved: bpf: Fix memleak due to fentry attach failure If it fails to attach fentry, the allocated bpf trampoline image will be left in the system. That can be verified by checking /proc/kallsyms. This meamleak can be verified by a simple bpf program as follows: SEC("fentry/trap_init") int fentry_run() { return 0; } It will fail to attach trap_init because this function is freed after kernel init, and then we can find the trampoline image is left in the system by checking /proc/kallsyms. $ tail /proc/kallsyms ffffffffc0613000 t bpf_trampoline_6442453466_1 [bpf] ffffffffc06c3000 t bpf_trampoline_6442453466_1 [bpf] $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "FUNC 'trap_init'" [2522] FUNC 'trap_init' type_id=119 linkage=static $ echo $((6442453466 & 0x7fffffff)) 2522 Note that there are two left bpf trampoline images, that is because the libbpf will fallback to raw tracepoint if -EINVAL is returned.
Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 03 Dec 2025 15:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-401
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.12:-:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.12:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.12:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.12:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.12:rc8:*:*:*:*:*:*
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

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'}


Wed, 17 Sep 2025 11:00:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Vendors & Products Linux
Linux linux Kernel

Tue, 16 Sep 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Mon, 15 Sep 2025 14:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: bpf: Fix memleak due to fentry attach failure If it fails to attach fentry, the allocated bpf trampoline image will be left in the system. That can be verified by checking /proc/kallsyms. This meamleak can be verified by a simple bpf program as follows: SEC("fentry/trap_init") int fentry_run() { return 0; } It will fail to attach trap_init because this function is freed after kernel init, and then we can find the trampoline image is left in the system by checking /proc/kallsyms. $ tail /proc/kallsyms ffffffffc0613000 t bpf_trampoline_6442453466_1 [bpf] ffffffffc06c3000 t bpf_trampoline_6442453466_1 [bpf] $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep "FUNC 'trap_init'" [2522] FUNC 'trap_init' type_id=119 linkage=static $ echo $((6442453466 & 0x7fffffff)) 2522 Note that there are two left bpf trampoline images, that is because the libbpf will fallback to raw tracepoint if -EINVAL is returned.
Title bpf: Fix memleak due to fentry attach failure
References

cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-09-15T14:21:50.053Z

Reserved: 2025-09-15T14:19:21.845Z

Link: CVE-2023-53221

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2025-09-15T15:15:48.873

Modified: 2025-12-03T15:27:46.513

Link: CVE-2023-53221

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-09-15T00:00:00Z

Links: CVE-2023-53221 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2025-09-17T10:07:45Z