CVE-2025-39852

MEDIUM EPSS 3.3%
Published Sep 19, 20259mo ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Sep 19, 2025 9mo ago
Last Modified Jun 17, 2026 1w ago

Description

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 Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
3.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-401

Affected Products 6

VendorProductVersionRange
linuxlinux_kernel*≥6.7  –  <6.12.46
linuxlinux_kernel*≥6.13  –  <6.16.6
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any
linuxlinux_kernel6.17any

References 3

  • git.kernel.org https://git.kernel.org/stable/c/3d2b356d994a8801acb397cafd28b13672c37ab5
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/46d33c878fc0b3d7570366b2c9912395b3f4e701
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fa390321aba0a54d0f7ae95ee4ecde1358bb9234
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/3d2b356d994a8801acb397cafd28b13672c37ab5
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/46d33c878fc0b3d7570366b2c9912395b3f4e701
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/fa390321aba0a54d0f7ae95ee4ecde1358bb9234
    Patch