CVE-2025-21683

Updated: 2026-02-27 00:52:28.965718

Description:

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix bpf_sk_select_reuseport() memory leak As pointed out in the original comment, lookup in sockmap can return a TCP ESTABLISHED socket. Such TCP socket may have had SO_ATTACH_REUSEPORT_EBPF set before it was ESTABLISHED. In other words, a non-NULL sk_reuseport_cb does not imply a non-refcounted socket. Drop sk's reference in both error paths. unreferenced object 0xffff888101911800 (size 2048): comm "test_progs", pid 44109, jiffies 4297131437 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 80 00 01 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace (crc 9336483b): __kmalloc_noprof+0x3bf/0x560 __reuseport_alloc+0x1d/0x40 reuseport_alloc+0xca/0x150 reuseport_attach_prog+0x87/0x140 sk_reuseport_attach_bpf+0xc8/0x100 sk_setsockopt+0x1181/0x1990 do_sock_setsockopt+0x12b/0x160 __sys_setsockopt+0x7b/0xc0 __x64_sys_setsockopt+0x1b/0x30 do_syscall_64+0x93/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e


Links NIST CIRCL RHEL Ubuntu

Severity

Severity Score
CVSS Version 2.x 0.0
CVSS Version 3.x MEDIUM 5.5

Status

OS name Project name Version Score Severity Status Errata Last updated

Statement

AlmaLinux 9.2 ESU kernel 5.14.0 5.5 MEDIUM Ignored 2025-02-07 06:33:31 This issue is a local-only memory leak in the BPF reuseport selection path that affects availability...
TuxCare 9.6 ESU kernel 5.14.0 5.5 MEDIUM Ignored 2025-07-05 02:18:13 This is a local-only memory leak in a narrow BPF error path (bpf_sk_select_reuseport with sockmap), ...