{"cve":"CVE-2023-53221","nvd":{"published":"2025-09-15T15:15:48.873","modified":"2026-06-17T06:44:32.793","status":"Modified","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-401"],"references":["https://git.kernel.org/stable/c/108598c39eefbedc9882273ac0df96127a629220","https://git.kernel.org/stable/c/20109ddd5bea2c24d790debf5d02584ef24c3f5e","https://git.kernel.org/stable/c/6aa27775db63ba8c7c73891c7dfb71ddc230c48d","https://git.kernel.org/stable/c/f72c67d1a82dada7d6d504c806e111e913721a30"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:08:41.295252406+00:00"},"epss":{"cve":"CVE-2023-53221","score":0.00159,"percentile":0.05034,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}