Medium 5.5Published Sep 19, 2025

CVE-2025-39852In the Linux kernel, the following vulnerability has been resolved: net/tcp: Fix socket memory leak in TCP-AO failure handling for IPv6 When tcp_ao_copy_all_matching() fails in tcp_v6_syn_recv_sock()…

Updated under an hour ago (2026-10-20 07:00 UTC)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: net/tcp: Fix socket memory leak in TCP-AO failure handling for IPv6 When tcp_ao_copy_all_matching() fails in tcp_v6_syn_recv_sock() it just exits the function. This ends up causing a memory-leak: unreferenced object 0xffff0000281a8200 (size 2496): comm "softirq", pid 0, jiffies 4295174684 hex dump (first 32 bytes): 7f 00 00 06 7f 00 00 06 00 00 00 00 cb a8 88 13 ................ 0a 00 03 61 00 00 00 00 00 00 00 00 00 00 00 00 ...a............ backtrace (crc 5ebdbe15): kmemleak_alloc+0x44/0xe0 kmem_cache_alloc_noprof+0x248/0x470 sk_prot_alloc+0x48/0x120 sk_clone_lock+0x38/0x3b0 inet_csk_clone_lock+0x34/0x150 tcp_create_openreq_child+0x3c/0x4a8 tcp_v6_syn_recv_sock+0x1c0/0x620 tcp_check_req+0x588/0x790 tcp_v6_rcv+0x5d0/0xc18 ip6_protocol_deliver_rcu+0x2d8/0x4c0 ip6_input_finish+0x74/0x148 ip6_input+0x50/0x118 ip6_sublist_rcv+0x2fc/0x3b0 ipv6_list_rcv+0x114/0x170 __netif_receive_skb_list_core+0x16c/0x200 netif_receive_skb_list_internal+0x1f0/0x2d0 This is because in tcp_v6_syn_recv_sock (and the IPv4 counterpart), when exiting upon error, inet_csk_prepare_forced_close() and tcp_done() need to be called. They make sure the newsk will end up being correctly free'd. tcp_v4_syn_recv_sock() makes this very clear by having the put_and_exit label that takes care of things. So, this patch here makes sure tcp_v4_syn_recv_sock and tcp_v6_syn_recv_sock have similar error-handling and thus fixes the leak for TCP-AO.

CVSS: 5.5 MEDIUM (v3.1, NVD)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: Not given
NVD analysis: Modified
Record last updated: Oct 19, 2026
First seen by InfoSec Signals: Oct 19, 2026

Affected products

Affected products

linux linux_kernel linux:linux_kernel	from 6.7 before 6.12.46; from 6.13 before 6.16.6; 6.17; 6.17; 6.17; 6.17	NVD

References

https://git.kernel.org/stable/c/3d2b356d994a8801acb397cafd28b13672c37ab5patch
https://git.kernel.org/stable/c/46d33c878fc0b3d7570366b2c9912395b3f4e701patch
https://git.kernel.org/stable/c/fa390321aba0a54d0f7ae95ee4ecde1358bb9234patch

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.