vxlan: do not arm the ageing timer on a device that is down
Summary
| CVE | CVE-2026-74615 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-22 16:16:34 UTC |
| Updated | 2026-08-25 06:18:39 UTC |
| Description | In the Linux kernel, the following vulnerability has been resolved: vxlan: do not arm the ageing timer on a device that is down vxlan_changelink() arms vxlan->age_timer whenever the requested ageing interval differs from the configured one: if (conf.age_interval != vxlan->cfg.age_interval) mod_timer(&vxlan->age_timer, jiffies); There is no netif_running() test, so the timer is armed even on a device that was never brought up. The only synchronous cancel in the driver is the timer_delete_sync() in vxlan_stop(), which is .ndo_stop. netif_close_many() drops devices without IFF_UP before __dev_close_many() runs, so that cancel is skipped for such a device. vxlan_setup() sets dev->needs_free_netdev = true and age_timer is a member of struct vxlan_dev, so free_netdev() releases the allocation the timer lives in while it is still queued on a timer_base. expire_timers() unlinks the entry before it loads timer->function, so the timer core writes through the freed object's list pointers: BUG: KASAN: slab-use-after-free in __run_timers+0x208/0x654 Write of size 8 at addr ffff00001adace68 by task true/192 __asan_store8+0x84/0xac __run_timers+0x208/0x654 run_timer_softirq+0x154/0x18c Allocated by task 189: alloc_netdev_mqs+0x64/0x720 rtnl_create_link+0x4ac/0x520 rtnl_newlink+0x758/0xd00 Freed by task 191: netdev_release+0x40/0x58 netdev_run_todo+0x4a4/0x8c0 rtnl_dellink+0x200/0x4e8 The rtnl operations involved are netns-scoped, so an unprivileged user can perform them in a new user and network namespace. Arming the timer on a down device never had an effect: vxlan_cleanup() returns early on !netif_running(), and vxlan_open() arms the timer for any non-zero interval once the device is brought up. Add the missing test. Discovered by XBOW, triaged by Baul Lee <[email protected]> |
Risk And Classification
Primary CVSS: v3.1 8.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
EPSS: 0.001260000 probability, percentile 0.024870000 (date 2026-08-25)
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | Secondary | 8.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 8.8 | HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
LowUser Interaction
NoneScope
ChangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 40051c4dcad5b374156ad9cceae8d15c0ef1cb95 be44d79d14d7f9ae7c8ffb7272142005341b5123 git | Not specified |
| CNA | Linux | Linux | affected 40051c4dcad5b374156ad9cceae8d15c0ef1cb95 26c179d47403d2f919ee914cc02c31d896b59fee git | Not specified |
| CNA | Linux | Linux | affected 40051c4dcad5b374156ad9cceae8d15c0ef1cb95 9dc561f0522c35bdd66e0646a748814a138ec4ca git | Not specified |
| CNA | Linux | Linux | affected 40051c4dcad5b374156ad9cceae8d15c0ef1cb95 619dd29045e439d0b0f8c6d4fec1af447a050680 git | Not specified |
| CNA | Linux | Linux | affected 40051c4dcad5b374156ad9cceae8d15c0ef1cb95 6b095e99b9e67ea31f0c4b00260e010898253519 git | Not specified |
| CNA | Linux | Linux | affected 40051c4dcad5b374156ad9cceae8d15c0ef1cb95 46bb297ad77680e009244f067f27d51cf5b8c7cf git | Not specified |
| CNA | Linux | Linux | affected 40051c4dcad5b374156ad9cceae8d15c0ef1cb95 6b4119af544996a545cf84b16f1dbce829ba0de8 git | Not specified |
| CNA | Linux | Linux | affected 40051c4dcad5b374156ad9cceae8d15c0ef1cb95 b37971686ec59fb027fa4910ba16805e68fddb97 git | Not specified |
| CNA | Linux | Linux | affected 5.0 | Not specified |
| CNA | Linux | Linux | unaffected 5.0 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.265 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.216 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.183 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.152 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.104 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.45 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.9 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/9dc561f0522c35bdd66e0646a748814a138ec4ca | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/b37971686ec59fb027fa4910ba16805e68fddb97 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/6b4119af544996a545cf84b16f1dbce829ba0de8 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/be44d79d14d7f9ae7c8ffb7272142005341b5123 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/46bb297ad77680e009244f067f27d51cf5b8c7cf | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/619dd29045e439d0b0f8c6d4fec1af447a050680 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/26c179d47403d2f919ee914cc02c31d896b59fee | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/6b095e99b9e67ea31f0c4b00260e010898253519 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.