{"id":"AZL-49785","summary":"CVE-2024-46858 affecting package kernel for versions less than 6.6.56.1-5","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: pm: Fix uaf in __timer_delete_sync\n\nThere are two paths to access mptcp_pm_del_add_timer, result in a race\ncondition:\n\n     CPU1\t\t\t\tCPU2\n     ====                               ====\n     net_rx_action\n     napi_poll                          netlink_sendmsg\n     __napi_poll                        netlink_unicast\n     process_backlog                    netlink_unicast_kernel\n     __netif_receive_skb                genl_rcv\n     __netif_receive_skb_one_core       netlink_rcv_skb\n     NF_HOOK                            genl_rcv_msg\n     ip_local_deliver_finish            genl_family_rcv_msg\n     ip_protocol_deliver_rcu            genl_family_rcv_msg_doit\n     tcp_v4_rcv                         mptcp_pm_nl_flush_addrs_doit\n     tcp_v4_do_rcv                      mptcp_nl_remove_addrs_list\n     tcp_rcv_established                mptcp_pm_remove_addrs_and_subflows\n     tcp_data_queue                     remove_anno_list_by_saddr\n     mptcp_incoming_options             mptcp_pm_del_add_timer\n     mptcp_pm_del_add_timer             kfree(entry)\n\nIn remove_anno_list_by_saddr(running on CPU2), after leaving the critical\nzone protected by \"pm.lock\", the entry will be released, which leads to the\noccurrence of uaf in the mptcp_pm_del_add_timer(running on CPU1).\n\nKeeping a reference to add_timer inside the lock, and calling\nsk_stop_timer_sync() with this reference, instead of \"entry-\u003eadd_timer\".\n\nMove list_del(&entry-\u003elist) to mptcp_pm_del_add_timer and inside the pm lock,\ndo not directly access any members of the entry outside the pm lock, which\ncan avoid similar \"entry-\u003ex\" uaf.","modified":"2026-04-01T05:16:12.745411Z","published":"2024-09-27T13:15:17Z","upstream":["CVE-2024-46858"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-46858"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.56.1-5"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-49785.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}