GHSA-JVQ3-C9FM-53R7
Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-17 06:33In the Linux kernel, the following vulnerability has been resolved:
ipv6: addrconf: bail out of dad_failure when state is no longer POSTDAD
addrconf_dad_failure() transitions ifp->state from DAD to POSTDAD via addrconf_dad_end(), which drops ifp->lock on return. The lock is re-acquired after net_info_ratelimited(). A concurrent ipv6_del_addr() can take the lock in that window, set ifp->state to DEAD and run list_del_rcu(&ifp->if_list).
addrconf_dad_failure() then overwrites DEAD with ERRDAD at errdad: and schedules a new dad_work. The work calls ipv6_del_addr() again, hitting the already-poisoned list entry:
general protection fault: 0000 [#1] SMP NOPTI CPU: 4 PID: 217 Comm: kworker/4:1 Workqueue: ipv6_addrconf addrconf_dad_work RIP: 0010:ipv6_del_addr+0xe9/0x280 RAX: dead000000000122 Call Trace: addrconf_dad_stop+0x113/0x140 addrconf_dad_work+0x28c/0x430 process_one_work+0x1eb/0x3b0 worker_thread+0x4d/0x400 kthread+0x104/0x140 ret_from_fork+0x35/0x40
Fold the addrconf_dad_end() logic into addrconf_dad_failure() under a single ifp->lock critical section. The STABLE_PRIVACY branch temporarily drops ifp->lock around address regeneration, so at lock_errdad: verify the state is still POSTDAD before transitioning to ERRDAD; bail out otherwise to avoid overwriting a state set by another path while the lock was released.
{
"affected": [],
"aliases": [
"CVE-2026-74398"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T06:22:41Z",
"severity": "CRITICAL"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: addrconf: bail out of dad_failure when state is no longer POSTDAD\n\naddrconf_dad_failure() transitions ifp-\u003estate from DAD to POSTDAD\nvia addrconf_dad_end(), which drops ifp-\u003elock on return. The lock\nis re-acquired after net_info_ratelimited(). A concurrent\nipv6_del_addr() can take the lock in that window, set ifp-\u003estate\nto DEAD and run list_del_rcu(\u0026ifp-\u003eif_list).\n\naddrconf_dad_failure() then overwrites DEAD with ERRDAD at errdad:\nand schedules a new dad_work. The work calls ipv6_del_addr()\nagain, hitting the already-poisoned list entry:\n\n general protection fault: 0000 [#1] SMP NOPTI\n CPU: 4 PID: 217 Comm: kworker/4:1\n Workqueue: ipv6_addrconf addrconf_dad_work\n RIP: 0010:ipv6_del_addr+0xe9/0x280\n RAX: dead000000000122\n Call Trace:\n addrconf_dad_stop+0x113/0x140\n addrconf_dad_work+0x28c/0x430\n process_one_work+0x1eb/0x3b0\n worker_thread+0x4d/0x400\n kthread+0x104/0x140\n ret_from_fork+0x35/0x40\n\nFold the addrconf_dad_end() logic into addrconf_dad_failure() under\na single ifp-\u003elock critical section. The STABLE_PRIVACY branch\ntemporarily drops ifp-\u003elock around address regeneration, so at\nlock_errdad: verify the state is still POSTDAD before transitioning\nto ERRDAD; bail out otherwise to avoid overwriting a state set by\nanother path while the lock was released.",
"id": "GHSA-jvq3-c9fm-53r7",
"modified": "2026-08-17T06:33:42Z",
"published": "2026-08-15T06:32:32Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74398"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3bdc86d89fd6c6523753fa6f42fcfaf30ee699cb"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/47b05836705b63dab93d9ac7c69a3a507375ef80"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/627ac78f2741e2ebd2225e2e953b6964a8a9182f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/875c284c0f98b042bb97abad460f63a24c977f88"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8ed0ce9ea58d677d1bac92614ee5f60f8ea57363"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b61af0268e3d1308c466bf0be5dced844eafc1ef"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d21be7d051012c6b572fa4e3334443c250216f7b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e889aa99ad3ed48bb0ddcff6475b17542532d18b"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
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Nomenclature
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