{"id":"AZL-104759","summary":"CVE-2026-98014 affecting package kernel 6.6.157.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5: E-Switch, prevent mc_list repopulation during vport disable\n\nIn mlx5_esw_vport_disable(), move esw_apply_vport_rx_mode() ahead\nof esw_vport_change_handle_locked() so vport-\u003eallmulti_rule is\nNULL before the change handler observes it.\n\nDuring FW-fatal recovery the disable runs while dev-\u003estate ==\nINTERNAL_ERROR. The promisc query inside esw_update_vport_rx_mode()\nfails and returns early, leaving vport-\u003eallmulti_rule intact, so\nesw_update_vport_mc_promisc() runs and adds MLX5_ACTION_ADD entries\nto vport-\u003emc_list whose flow rules are then installed in the FDB\nby esw_add_mc_addr(). esw_destroy_legacy_table() tears down the\nFDB with those refs still held, corrupting the sub-tree and\nleaving dangling flow_rule pointers in vport-\u003emc_list.\n\nTwo-stage failure on `echo 1 \u003e /sys/bus/pci/devices/\u003cbdf\u003e/reset`:\n\n  refcount_t: underflow; use-after-free.\n   tree_put_node+0xef/0x110 [mlx5_core]\n   clean_tree+0x44/0xd0 [mlx5_core] (x5)\n   mlx5_fs_core_cleanup+0x57/0x1c0 [mlx5_core]\n   mlx5_unload+0x65/0xd0 [mlx5_core]\n   ... mlx5_health_try_recover\n\n  BUG: unable to handle page fault for address: 0000000003000055\n   down_write+0x1c/0x60\n   mlx5_del_flow_rules+0x33/0x1f0 [mlx5_core]\n   esw_del_mc_addr+0x7b/0x170 [mlx5_core]\n   esw_apply_vport_addr_list+0x56/0xf0 [mlx5_core]\n   esw_vport_change_handle_locked+0x28b/0x310 [mlx5_core]\n   mlx5_esw_vport_enable+0x270/0x4a0 [mlx5_core]\n   ... mlx5_load ... mlx5_health_try_recover\n\nesw_apply_vport_rx_mode(false, false) clears vport-\u003eallmulti_rule\nvia its local state machine even when the FW del fails. With the\nrule NULL the !IS_ERR_OR_NULL(allmulti_rule) gate in the change\nhandler closes, no rules are installed during disable, and the\nreload starts with a clean mc_list.","modified":"2026-09-26T14:16:24.535379882Z","published":"2026-09-25T11:17:29Z","upstream":["CVE-2026-98014"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98014"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.157.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-104759.json"}}],"schema_version":"1.9.0"}