{"cve":"CVE-2026-74615","nvd":{"published":"2026-08-22T16:16:34.143","modified":"2026-10-16T20:17:46.847","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nvxlan: do not arm the ageing timer on a device that is down\n\nvxlan_changelink() arms vxlan->age_timer whenever the requested ageing\ninterval differs from the configured one:\n\n\tif (conf.age_interval != vxlan->cfg.age_interval)\n\t\tmod_timer(&vxlan->age_timer, jiffies);\n\nThere is no netif_running() test, so the timer is armed even on a device\nthat was never brought up.  The only synchronous cancel in the driver is\nthe timer_delete_sync() in vxlan_stop(), which is .ndo_stop.\nnetif_close_many() drops devices without IFF_UP before\n__dev_close_many() runs, so that cancel is skipped for such a device.\n\nvxlan_setup() sets dev->needs_free_netdev = true and age_timer is a\nmember of struct vxlan_dev, so free_netdev() releases the allocation the\ntimer lives in while it is still queued on a timer_base.\nexpire_timers() unlinks the entry before it loads timer->function, so\nthe timer core writes through the freed object's list pointers:\n\n  BUG: KASAN: slab-use-after-free in __run_timers+0x208/0x654\n  Write of size 8 at addr ffff00001adace68 by task true/192\n   __asan_store8+0x84/0xac\n   __run_timers+0x208/0x654\n   run_timer_softirq+0x154/0x18c\n  Allocated by task 189:\n   alloc_netdev_mqs+0x64/0x720\n   rtnl_create_link+0x4ac/0x520\n   rtnl_newlink+0x758/0xd00\n  Freed by task 191:\n   netdev_release+0x40/0x58\n   netdev_run_todo+0x4a4/0x8c0\n   rtnl_dellink+0x200/0x4e8\n\nThe rtnl operations involved are netns-scoped, so an unprivileged user\ncan perform them in a new user and network namespace.\n\nArming the timer on a down device never had an effect: vxlan_cleanup()\nreturns early on !netif_running(), and vxlan_open() arms the timer for\nany non-zero interval once the device is brought up.  Add the missing\ntest.\n\nDiscovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H","score":8.8},"cwes":[],"references":["https://git.kernel.org/stable/c/26c179d47403d2f919ee914cc02c31d896b59fee","https://git.kernel.org/stable/c/46bb297ad77680e009244f067f27d51cf5b8c7cf","https://git.kernel.org/stable/c/619dd29045e439d0b0f8c6d4fec1af447a050680","https://git.kernel.org/stable/c/6b095e99b9e67ea31f0c4b00260e010898253519","https://git.kernel.org/stable/c/6b4119af544996a545cf84b16f1dbce829ba0de8"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:49:38.260478770+00:00"},"epss":{"cve":"CVE-2026-74615","score":0.00126,"percentile":0.02232,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}