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.
Published: 2026-08-15
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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History

Sat, 15 Aug 2026 06:15:00 +0000

Type Values Removed Values Added
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.
Title ipv6: addrconf: bail out of dad_failure when state is no longer POSTDAD
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

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Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-08-15T05:59:10.113Z

Reserved: 2026-08-15T05:44:03.891Z

Link: CVE-2026-74398

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-08-15T06:22:41.790

Modified: 2026-08-15T06:22:41.790

Link: CVE-2026-74398

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.