{"id":"CVE-2024-41040","summary":"net/sched: Fix UAF when resolving a clash","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: Fix UAF when resolving a clash\n\nKASAN reports the following UAF:\n\n BUG: KASAN: slab-use-after-free in tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct]\n Read of size 1 at addr ffff888c07603600 by task handler130/6469\n\n Call Trace:\n  \u003cIRQ\u003e\n  dump_stack_lvl+0x48/0x70\n  print_address_description.constprop.0+0x33/0x3d0\n  print_report+0xc0/0x2b0\n  kasan_report+0xd0/0x120\n  __asan_load1+0x6c/0x80\n  tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct]\n  tcf_ct_act+0x886/0x1350 [act_ct]\n  tcf_action_exec+0xf8/0x1f0\n  fl_classify+0x355/0x360 [cls_flower]\n  __tcf_classify+0x1fd/0x330\n  tcf_classify+0x21c/0x3c0\n  sch_handle_ingress.constprop.0+0x2c5/0x500\n  __netif_receive_skb_core.constprop.0+0xb25/0x1510\n  __netif_receive_skb_list_core+0x220/0x4c0\n  netif_receive_skb_list_internal+0x446/0x620\n  napi_complete_done+0x157/0x3d0\n  gro_cell_poll+0xcf/0x100\n  __napi_poll+0x65/0x310\n  net_rx_action+0x30c/0x5c0\n  __do_softirq+0x14f/0x491\n  __irq_exit_rcu+0x82/0xc0\n  irq_exit_rcu+0xe/0x20\n  common_interrupt+0xa1/0xb0\n  \u003c/IRQ\u003e\n  \u003cTASK\u003e\n  asm_common_interrupt+0x27/0x40\n\n Allocated by task 6469:\n  kasan_save_stack+0x38/0x70\n  kasan_set_track+0x25/0x40\n  kasan_save_alloc_info+0x1e/0x40\n  __kasan_krealloc+0x133/0x190\n  krealloc+0xaa/0x130\n  nf_ct_ext_add+0xed/0x230 [nf_conntrack]\n  tcf_ct_act+0x1095/0x1350 [act_ct]\n  tcf_action_exec+0xf8/0x1f0\n  fl_classify+0x355/0x360 [cls_flower]\n  __tcf_classify+0x1fd/0x330\n  tcf_classify+0x21c/0x3c0\n  sch_handle_ingress.constprop.0+0x2c5/0x500\n  __netif_receive_skb_core.constprop.0+0xb25/0x1510\n  __netif_receive_skb_list_core+0x220/0x4c0\n  netif_receive_skb_list_internal+0x446/0x620\n  napi_complete_done+0x157/0x3d0\n  gro_cell_poll+0xcf/0x100\n  __napi_poll+0x65/0x310\n  net_rx_action+0x30c/0x5c0\n  __do_softirq+0x14f/0x491\n\n Freed by task 6469:\n  kasan_save_stack+0x38/0x70\n  kasan_set_track+0x25/0x40\n  kasan_save_free_info+0x2b/0x60\n  ____kasan_slab_free+0x180/0x1f0\n  __kasan_slab_free+0x12/0x30\n  slab_free_freelist_hook+0xd2/0x1a0\n  __kmem_cache_free+0x1a2/0x2f0\n  kfree+0x78/0x120\n  nf_conntrack_free+0x74/0x130 [nf_conntrack]\n  nf_ct_destroy+0xb2/0x140 [nf_conntrack]\n  __nf_ct_resolve_clash+0x529/0x5d0 [nf_conntrack]\n  nf_ct_resolve_clash+0xf6/0x490 [nf_conntrack]\n  __nf_conntrack_confirm+0x2c6/0x770 [nf_conntrack]\n  tcf_ct_act+0x12ad/0x1350 [act_ct]\n  tcf_action_exec+0xf8/0x1f0\n  fl_classify+0x355/0x360 [cls_flower]\n  __tcf_classify+0x1fd/0x330\n  tcf_classify+0x21c/0x3c0\n  sch_handle_ingress.constprop.0+0x2c5/0x500\n  __netif_receive_skb_core.constprop.0+0xb25/0x1510\n  __netif_receive_skb_list_core+0x220/0x4c0\n  netif_receive_skb_list_internal+0x446/0x620\n  napi_complete_done+0x157/0x3d0\n  gro_cell_poll+0xcf/0x100\n  __napi_poll+0x65/0x310\n  net_rx_action+0x30c/0x5c0\n  __do_softirq+0x14f/0x491\n\nThe ct may be dropped if a clash has been resolved but is still passed to\nthe tcf_ct_flow_table_process_conn function for further usage. This issue\ncan be fixed by retrieving ct from skb again after confirming conntrack.","modified":"2026-04-02T12:16:32.479495Z","published":"2024-07-29T14:31:53.853Z","related":["ALSA-2024:6567","ALSA-2024:7000","ALSA-2024:7001","MGASA-2024-0277","MGASA-2024-0278","SUSE-SU-2024:2894-1","SUSE-SU-2024:2939-1","SUSE-SU-2024:2947-1","SUSE-SU-2024:3194-1","SUSE-SU-2024:3195-1","SUSE-SU-2024:3383-1","SUSE-SU-2025:20044-1","SUSE-SU-2025:20047-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/41xxx/CVE-2024-41040.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/26488172b0292bed837b95a006a3f3431d1898c3"},{"type":"WEB","url":"https://git.kernel.org/stable/c/2b4d68df3f57ea746c430941ba9c03d7d8b5a23f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4e71b10a100861fb27d9c5755dfd68f615629fae"},{"type":"WEB","url":"https://git.kernel.org/stable/c/799a34901b634008db4a7ece3900e2b971d4c932"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b81a523d54ea689414f67c9fb81a5b917a41ed55"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ef472cc6693b16b202a916482df72f35d94bd69e"},{"type":"WEB","url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/41xxx/CVE-2024-41040.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-41040"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"f07c548314776231f0d47d73ec6caa5b17e876e8"},{"fixed":"b81a523d54ea689414f67c9fb81a5b917a41ed55"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0cc254e5aa37cf05f65bcdcdc0ac5c58010feb33"},{"fixed":"2b4d68df3f57ea746c430941ba9c03d7d8b5a23f"},{"fixed":"4e71b10a100861fb27d9c5755dfd68f615629fae"},{"fixed":"799a34901b634008db4a7ece3900e2b971d4c932"},{"fixed":"ef472cc6693b16b202a916482df72f35d94bd69e"},{"fixed":"26488172b0292bed837b95a006a3f3431d1898c3"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0"},{"last_affected":"30822781c89943b6a3ed122324ceb37cea7042a3"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-41040.json"}}],"schema_version":"1.7.5"}