GHSA-X37V-HM75-XVF9
Vulnerability from github – Published: 2026-07-19 12:30 – Updated: 2026-07-20 15:31In the Linux kernel, the following vulnerability has been resolved:
net/tcp-ao: fix use-after-free of key in del_async path
In tcp_ao_delete_key(), the del_async path skips the current_key and rnext_key validity checks present in the synchronous path, assuming these pointers are always NULL on LISTEN sockets. However, if a key was added with set_current=1/set_rnext=1 while the socket was in CLOSE state, current_key and rnext_key will be non-NULL after listen() transitions the socket to LISTEN.
When such a key is deleted with del_async=1, hlist_del_rcu() and call_rcu() free the key without clearing the dangling pointers. After the RCU grace period, getsockopt(TCP_AO_INFO) dereferences current_key->sndid and rnext_key->rcvid from freed slab memory.
Clear current_key and rnext_key in the del_async path when they reference the key being deleted.
{
"affected": [],
"aliases": [
"CVE-2026-53389"
],
"database_specific": {
"cwe_ids": [
"CWE-416"
],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T12:16:49Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tcp-ao: fix use-after-free of key in del_async path\n\nIn tcp_ao_delete_key(), the del_async path skips the current_key\nand rnext_key validity checks present in the synchronous path,\nassuming these pointers are always NULL on LISTEN sockets. However,\nif a key was added with set_current=1/set_rnext=1 while the socket\nwas in CLOSE state, current_key and rnext_key will be non-NULL\nafter listen() transitions the socket to LISTEN.\n\nWhen such a key is deleted with del_async=1, hlist_del_rcu() and\ncall_rcu() free the key without clearing the dangling pointers.\nAfter the RCU grace period, getsockopt(TCP_AO_INFO) dereferences\ncurrent_key-\u003esndid and rnext_key-\u003ercvid from freed slab memory.\n\nClear current_key and rnext_key in the del_async path when they\nreference the key being deleted.",
"id": "GHSA-x37v-hm75-xvf9",
"modified": "2026-07-20T15:31:44Z",
"published": "2026-07-19T12:30:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53389"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5ba9950bc9078e19b69cca1e56d1553b125c6857"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6ce7ef41743740ce15c2061561b784148b565b3f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7ddc29a094d96e9b3aa280433c6dc443df9eabf2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e77fbefd1269b5c123e7c651a1ebdce1b87d19a0"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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