cbcvebase.
CVE-2025-39852
published 2025-09-19

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

PriorityP418medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.14%
3.3th percentile
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.

Affected

12 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.16.6-1 (forky)linux 6.16.6-1 (forky)
linuxlinux
linuxlinux>= 06b22ef29591f625ef877ae00d82192938e29e60 < 46d33c878fc0b3d7570366b2c9912395b3f4e70146d33c878fc0b3d7570366b2c9912395b3f4e701
linuxlinux>= 06b22ef29591f625ef877ae00d82192938e29e60 < 3d2b356d994a8801acb397cafd28b13672c37ab53d2b356d994a8801acb397cafd28b13672c37ab5
linuxlinux>= 06b22ef29591f625ef877ae00d82192938e29e60 < fa390321aba0a54d0f7ae95ee4ecde1358bb9234fa390321aba0a54d0f7ae95ee4ecde1358bb9234
linuxlinux_kernel
linuxlinux_kernel>= 0 < 6.12.48-16.12.48-1
linuxlinux_kernel>= 0 < 6.16.6-16.16.6-1
linuxlinux_kernel>= 0 < 6.8.0-106.1066.8.0-106.106
linuxlinux_kernel>= 6.13 < 6.16.66.16.6
linuxlinux_kernel>= 6.7 < 6.12.466.12.46
ubuntulinux-xilinx

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_ubuntu7.8HIGH
vendor_debian5.5LOW
vendor_redhat5.5MEDIUM
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