CVE-2026-74398
Received
Received - Intake
Use-After-Free in Linux Kernel IPv6 Address Configuration
Vulnerability report for CVE-2026-74398, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-08-15
Last updated on: 2026-08-15
Assigner: kernel.org
Description
Description
In 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.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
