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.
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.
Metrics
Affected Vendors & Products
No data.
No data.
No data.
No data.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Fri, 19 Sep 2025 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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. | |
| Title | net/tcp: Fix socket memory leak in TCP-AO failure handling for IPv6 | |
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-09-19T15:26:24.312Z
Reserved: 2025-04-16T07:20:57.142Z
Link: CVE-2025-39852
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-09-19T16:15:44.090
Modified: 2025-09-19T16:15:44.090
Link: CVE-2025-39852
Redhat
No data.
OpenCVE Enrichment
No data.