{"cve":"CVE-2026-98369","nvd":{"published":"2026-10-06T09:18:31.280","modified":"2026-10-19T10:18:40.010","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: add missing rcu_read_lock(), skb_dst_force() and dev_hold() for xfrm_trans_reinject()\n\nsyzbot reported a suspicious RCU usage warning in ip6_pkt_drop():\n\n  WARNING: suspicious RCU usage in ip6_pkt_drop\n  include/net/addrconf.h:389 suspicious rcu_dereference_check() usage!\n\n  Call Trace:\n   __in6_dev_get_safely include/net/addrconf.h:389 [inline]\n   ip6_pkt_drop+0x596/0x610 net/ipv6/route.c:4620\n   ip6_pkt_discard+0x1c/0x30 net/ipv6/route.c:4651\n   xfrm_trans_reinject+0x324/0x630 net/xfrm/xfrm_input.c:806\n   process_one_work kernel/workqueue.c:3322 [inline]\n   process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405\n   worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486\n\nWhen commit 4f4920669d21 (\"xfrm: Reinject transport-mode packets through\nworkqueue\") converted xfrm_trans_reinject from a tasklet to a workqueue,\nthe reinjection loop ceased running in softirq context. Workqueue workers\nrun in process context where local_bh_disable() does not enter an RCU\nread-side critical section under CONFIG_PREEMPT_RCU.\n\nBecause finish callbacks (such as ip6_rcv_finish) expect to run under an\nRCU read lock (performing route lookups, l3mdev lookups, and accessing\nRCU-protected data structures), invoking them in workqueue context without\nrcu_read_lock() triggers RCU lockdep warnings.\n\nFurthermore, packets queued to the workqueue via xfrm_trans_queue_net()\nmay carry non-refcounted (noref) dst entries (e.g. from ip_route_input_noref).\nAdditionally, on netdevice unregistration, dst_dev_put() replaces dst->dev\nwith blackhole_netdev, so dst entries do not keep skb->dev alive while\nqueued in the workqueue.\n\nFix these issues by:\n1. Calling skb_dst_force(skb) in xfrm_trans_queue_net() while still in the\n   caller's RCU section to ensure dst is reference-counted before queuing.\n2. Holding a reference on skb->dev via dev_hold()/dev_put() across workqueue\n   deferral so skb->dev remains valid during finish() callback processing.\n3. Acquiring rcu_read_lock() around the finish callback invocation loop in\n   xfrm_trans_reinject().","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/0cda8273265d30cac6423834fd7d4acb75f04fdb","https://git.kernel.org/stable/c/41e47f1664be86c91326f0afe0504a1162d00907","https://git.kernel.org/stable/c/6601d91a85761f33351c71e04ec0bbd294ca07ce","https://git.kernel.org/stable/c/664fc0941df7c1918b2cd4de6ee00469ba77d8e4","https://git.kernel.org/stable/c/68a317b4aec8ca1868a39d69e40f9e29baa4f40a"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:57:46.668721662+00:00"},"epss":{"cve":"CVE-2026-98369","score":0.00136,"percentile":0.02998,"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."]}