{"apiVersion":"1.0","identifier":"CVE-2026-99117","description":"In the Linux kernel, the following vulnerability has been resolved: net: bridge: mcast: don-t truncate the port group walk on teardown __br_multicast_disable_port_ctx() and br_multicast_del_port() walk port->mglist with hlist_for_each_entry_safe(). However, br_multicast_find_del_pg() can also delete other entries from the same list through br_multicast_fwd_src_remove() or __fwd_del_star_excl(). If such an entry is the iterator-s saved next node, hlist_del_init() clears its ->next and terminates the walk early. The reproducer triggers this in both teardown walks, leaving port groups in the bridge mdb with a dangling ->key.port after del_nbp() frees the port: BUG: KASAN: slab-use-after-free in __mdb_fill_info+0x1191/0x1320 __mdb_fill_info+0x1191/0x1320 br_mdb_dump+0x594/0xe40 rtnl_mdb_dump+0x1cf/0x5d0 Use hlist_del_init_rcu() to unlink the group while preserving ->next. br_multicast_del_pg() and the teardown walks run under br->multicast_lock. The GC worker must acquire the same lock before detaching the group for destruction, so the node remains alive while the walk uses the preserved pointer. Preserving ->next means a walk can now reach a group that an earlier iteration already deleted as a side effect. That group is off mp->ports, so br_multicast_find_del_pg() would fall through its port scan and hit the trailing WARN_ON(1). Skip such groups at the top of that helper: a port group is put on port->mglist when it is created and only unlinked when it is deleted, so hlist_unhashed() identifies exactly this case.","publishedAt":"2026-10-28T11:17:31","lastModifiedAt":"2026-10-31T13:17:56","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-99117","cvssScore":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","epssProbability":0.00126,"riskScore":0.79,"affectedProduct":"Linux kernel","affectedVersions":"unknown","vulnerabilityType":"Kernel","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-99117","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-99117","en":"https://www.redsauce.net/en/cves/CVE-2026-99117","fr":"https://www.redsauce.net/fr/cves/CVE-2026-99117","pt":"https://www.redsauce.net/pt/cves/CVE-2026-99117","de":"https://www.redsauce.net/de/cves/CVE-2026-99117","sk":"https://www.redsauce.net/sk/cves/CVE-2026-99117","el":"https://www.redsauce.net/el/cves/CVE-2026-99117"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-99117"}}