Medium 5.5Published Jan 31, 2025

CVE-2025-21683bpf: Fix bpf_sk_select_reuseport() memory leak

Updated under an hour ago (Oct 27, 2026, 9:23 AM ET)

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Exploited in the last 30 days

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

CVSS: 5.5 MEDIUM (v3.1, CISA ADP)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-401
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Not yet received
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 14, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 64d85290d79c0677edb5a8ee2295b36c022fa5df before bb36838dac7bb334a3f3d7eb29875593ec9473fc; 64d85290d79c0677edb5a8ee2295b36c022fa5df builds before 0ab52a8ca6e156a64c51b5e7456cac9a0ebfd9bf; from 64d85290d79c0677edb5a8ee2295b36c022fa5df before d0a3b3d1176d39218b8edb2a2d03164942ab9ccd; from 64d85290d79c0677edb5a8ee2295b36c022fa5df before b02e70be498b138e9c21701c2f33f4018ca7cd5e; from 64d85290d79c0677edb5a8ee2295b36c022fa5df before cccd51dd22574216e64e5d205489e634f86999f3; from 64d85290d79c0677edb5a8ee2295b36c022fa5df before b3af60928ab9129befa65e6df0310d27300942bf	CNA record
Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem siemens:simatic_s7_1500_tm_mfp_gnu_linux_subsystem (from the name)	all versions	CISA ADP

References

References

https://git.kernel.org/stable/c/bb36838dac7bb334a3f3d7eb29875593ec9473fc
https://git.kernel.org/stable/c/0ab52a8ca6e156a64c51b5e7456cac9a0ebfd9bf
https://git.kernel.org/stable/c/d0a3b3d1176d39218b8edb2a2d03164942ab9ccd
https://git.kernel.org/stable/c/b02e70be498b138e9c21701c2f33f4018ca7cd5e
https://git.kernel.org/stable/c/cccd51dd22574216e64e5d205489e634f86999f3
https://git.kernel.org/stable/c/b3af60928ab9129befa65e6df0310d27300942bf

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.