{"id":"CVE-2023-53221","summary":"bpf: Fix memleak due to fentry attach failure","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix memleak due to fentry attach failure\n\nIf it fails to attach fentry, the allocated bpf trampoline image will be\nleft in the system. That can be verified by checking /proc/kallsyms.\n\nThis meamleak can be verified by a simple bpf program as follows:\n\n  SEC(\"fentry/trap_init\")\n  int fentry_run()\n  {\n      return 0;\n  }\n\nIt will fail to attach trap_init because this function is freed after\nkernel init, and then we can find the trampoline image is left in the\nsystem by checking /proc/kallsyms.\n\n  $ tail /proc/kallsyms\n  ffffffffc0613000 t bpf_trampoline_6442453466_1  [bpf]\n  ffffffffc06c3000 t bpf_trampoline_6442453466_1  [bpf]\n\n  $ bpftool btf dump file /sys/kernel/btf/vmlinux | grep \"FUNC 'trap_init'\"\n  [2522] FUNC 'trap_init' type_id=119 linkage=static\n\n  $ echo $((6442453466 & 0x7fffffff))\n  2522\n\nNote that there are two left bpf trampoline images, that is because the\nlibbpf will fallback to raw tracepoint if -EINVAL is returned.","modified":"2026-04-02T09:43:49.439238Z","published":"2025-09-15T14:21:50.053Z","related":["SUSE-SU-2025:03600-1","SUSE-SU-2025:03634-1","SUSE-SU-2025:20851-1","SUSE-SU-2025:20861-1","SUSE-SU-2025:20870-1","SUSE-SU-2025:20898-1","SUSE-SU-2025:3751-1","SUSE-SU-2025:4057-1","SUSE-SU-2025:4132-1","SUSE-SU-2025:4141-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53221.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/108598c39eefbedc9882273ac0df96127a629220"},{"type":"WEB","url":"https://git.kernel.org/stable/c/20109ddd5bea2c24d790debf5d02584ef24c3f5e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6aa27775db63ba8c7c73891c7dfb71ddc230c48d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f72c67d1a82dada7d6d504c806e111e913721a30"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53221.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-53221"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"e21aa341785c679dd409c8cb71f864c00fe6c463"},{"fixed":"20109ddd5bea2c24d790debf5d02584ef24c3f5e"},{"fixed":"f72c67d1a82dada7d6d504c806e111e913721a30"},{"fixed":"6aa27775db63ba8c7c73891c7dfb71ddc230c48d"},{"fixed":"108598c39eefbedc9882273ac0df96127a629220"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0"},{"last_affected":"e21d2b92354b3cd25dd774ebb0f0e52ff04a7861"},{"last_affected":"85d177f56e5256e14b74a65940f981f6e3e8bb32"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-53221.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}