GHSA-H53C-6597-VMFW
Vulnerability from github – Published: 2026-04-24 15:32 – Updated: 2026-04-24 15:32In the Linux kernel, the following vulnerability has been resolved:
wireguard: device: use exit_rtnl callback instead of manual rtnl_lock in pre_exit
wg_netns_pre_exit() manually acquires rtnl_lock() inside the pernet .pre_exit callback. This causes a hung task when another thread holds rtnl_mutex - the cleanup_net workqueue (or the setup_net failure rollback path) blocks indefinitely in wg_netns_pre_exit() waiting to acquire the lock.
Convert to .exit_rtnl, introduced in commit 7a60d91c690b ("net: Add ->exit_rtnl() hook to struct pernet_operations."), where the framework already holds RTNL and batches all callbacks under a single rtnl_lock()/rtnl_unlock() pair, eliminating the contention window.
The rcu_assign_pointer(wg->creating_net, NULL) is safe to move from .pre_exit to .exit_rtnl (which runs after synchronize_rcu()) because all RCU readers of creating_net either use maybe_get_net() - which returns NULL for a dying namespace with zero refcount - or access net->user_ns which remains valid throughout the entire ops_undo_list sequence.
[ Jason: added __net_exit and __read_mostly annotations that were missing. ]
{
"affected": [],
"aliases": [
"CVE-2026-31579"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-04-24T15:16:32Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nwireguard: device: use exit_rtnl callback instead of manual rtnl_lock in pre_exit\n\nwg_netns_pre_exit() manually acquires rtnl_lock() inside the\npernet .pre_exit callback. This causes a hung task when another\nthread holds rtnl_mutex - the cleanup_net workqueue (or the\nsetup_net failure rollback path) blocks indefinitely in\nwg_netns_pre_exit() waiting to acquire the lock.\n\nConvert to .exit_rtnl, introduced in commit 7a60d91c690b (\"net:\nAdd -\u003eexit_rtnl() hook to struct pernet_operations.\"), where the\nframework already holds RTNL and batches all callbacks under a\nsingle rtnl_lock()/rtnl_unlock() pair, eliminating the contention\nwindow.\n\nThe rcu_assign_pointer(wg-\u003ecreating_net, NULL) is safe to move\nfrom .pre_exit to .exit_rtnl (which runs after synchronize_rcu())\nbecause all RCU readers of creating_net either use maybe_get_net()\n- which returns NULL for a dying namespace with zero refcount - or\naccess net-\u003euser_ns which remains valid throughout the entire\nops_undo_list sequence.\n\n[ Jason: added __net_exit and __read_mostly annotations that were missing. ]",
"id": "GHSA-h53c-6597-vmfw",
"modified": "2026-04-24T15:32:34Z",
"published": "2026-04-24T15:32:34Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-31579"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1c52ef00e391144334f10995985c2f256d4be982"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9a9e69155b2091b8297afaf1533b8d68a3096841"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a1d0f6cbb962af29586e3e65a4bced1a5e39221f"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.