CVE-2026-74398 (GCVE-0-2026-74398)
Vulnerability from cvelistv5
Published
2026-08-15 05:59
Modified
2026-08-17 05:46
Severity ?
VLAI Severity ?
EPSS score ?
Summary
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.
References
Impacted products
| Vendor | Product | Version | ||
|---|---|---|---|---|
| Linux | Linux |
Version: c15b1ccadb323ea50023e8f1cca2954129a62b51 Version: c15b1ccadb323ea50023e8f1cca2954129a62b51 Version: c15b1ccadb323ea50023e8f1cca2954129a62b51 Version: c15b1ccadb323ea50023e8f1cca2954129a62b51 Version: c15b1ccadb323ea50023e8f1cca2954129a62b51 Version: c15b1ccadb323ea50023e8f1cca2954129a62b51 Version: c15b1ccadb323ea50023e8f1cca2954129a62b51 Version: c15b1ccadb323ea50023e8f1cca2954129a62b51 Version: 835b474b8f70fa68d68abffad37378e92f661802 Version: 3.10.105 ≤ |
||
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"net/ipv6/addrconf.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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},
{
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{
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]
},
{
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"product": "Linux",
"programFiles": [
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],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "3.14"
},
{
"lessThan": "3.14",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.97",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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},
{
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{
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{
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{
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}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "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."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:N - The bug is reached from inbound ICMPv6 Neighbor Discovery (NS/NA) packets processed by icmp6_rcv()\u2192ndisc_rcv()\u2192addrconf_dad_failure(), the standard IPv6 network receive path on internet-facing servers, cloud VMs, phones, and IoT devices on shared L2 segments.\nAC:L - An attacker controls both sides of the race by flooding forged NS/NA during DAD while concurrently triggering ipv6_del_addr() via RTM_DELADDR/CAP_NET_ADMIN in a user namespace, CNI/orchestration address teardown, or interface-down processing; retries make the narrow window reliably winnable.\nPR:N - Triggering DAD failure requires only unauthenticated ND packet injection on the victim\u0027s link; the concurrent ipv6_del_addr() leg needs no victim credentials and can come from automatic address lifecycle events (CNI churn, SLAAC/privacy regeneration, netdev down) rather than attacker admin rights.\nUI:N - Exploitation does not require any victim user action such as opening files or mounting filesystems; it targets automatic IPv6 address configuration and DAD processing that occurs during normal network connectivity and boot.\nS:U - The corrupted inet6_ifaddr lifecycle and resulting kernel crash occur within kernel memory management; impact does not cross a VM, container, or IOMMU security boundary into a separate authority.\nC:H - The race leaves a freed/partially torn-down inet6_ifaddr with corrupted state and a poisoned RCU list entry (LIST_POISON2), constituting use-after-free class memory corruption that can expose adjacent kernel heap contents beyond a pure crash.\nI:H - Corrupting inet6_ifaddr state after list_del_rcu() and re-queuing dad_work on a dead object enables heap reuse and control of freed object contents, providing a path to arbitrary kernel memory writes and potential code execution beyond denial of service.\nA:H - The demonstrated failure is a general protection fault in ipv6_del_addr() from addrconf_dad_work on the ipv6_addrconf workqueue, causing a kernel oops/panic and complete loss of system availability on affected hosts."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T05:46:43.132Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/47b05836705b63dab93d9ac7c69a3a507375ef80"
},
{
"url": "https://git.kernel.org/stable/c/d21be7d051012c6b572fa4e3334443c250216f7b"
},
{
"url": "https://git.kernel.org/stable/c/875c284c0f98b042bb97abad460f63a24c977f88"
},
{
"url": "https://git.kernel.org/stable/c/8ed0ce9ea58d677d1bac92614ee5f60f8ea57363"
},
{
"url": "https://git.kernel.org/stable/c/3bdc86d89fd6c6523753fa6f42fcfaf30ee699cb"
},
{
"url": "https://git.kernel.org/stable/c/b61af0268e3d1308c466bf0be5dced844eafc1ef"
},
{
"url": "https://git.kernel.org/stable/c/e889aa99ad3ed48bb0ddcff6475b17542532d18b"
},
{
"url": "https://git.kernel.org/stable/c/627ac78f2741e2ebd2225e2e953b6964a8a9182f"
}
],
"title": "ipv6: addrconf: bail out of dad_failure when state is no longer POSTDAD",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74398",
"datePublished": "2026-08-15T05:59:10.113Z",
"dateReserved": "2026-08-15T05:44:03.891Z",
"dateUpdated": "2026-08-17T05:46:43.132Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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