{"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":"2026-10-28T02:31:02.708043063Z","published":"2024-07-29T14:31:53.853Z","related":["ALSA-2024:6567","ALSA-2024:7000","ALSA-2024:7001","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":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/41xxx/CVE-2024-41040.json"},"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":"5.10.43"},{"fixed":"5.10.222"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.12.10"},{"fixed":"5.13"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"30822781c89943b6a3ed122324ceb37cea7042a3"}]}],"versions":["v5.10.221","v5.10.220","v5.10.219","v5.10.218","v5.10.217","v5.10.216","v5.10.215","v5.10.214","v5.10.213","v5.10.212","v5.10.211","v5.10.210","v5.10.209","v5.10.208","v5.10.207","v5.10.206","v5.10.205","v5.10.204","v5.10.203","v5.10.202","v5.10.201","v5.10.200","v5.10.199","v5.10.198","v5.10.197","v5.10.196","v5.10.195","v5.10.194","v5.10.193","v5.10.192","v5.10.191","v5.10.190","v5.10.189","v5.10.188","v5.10.187","v5.10.186","v5.10.185","v5.10.184","v5.10.183","v5.10.182","v5.10.181","v5.10.180","v5.10.179","v5.10.178","v5.10.177","v5.10.176","v5.10.175","v5.10.174","v5.10.173","v5.10.172","v5.10.171","v5.10.170","v5.10.169","v5.10.168","v5.10.167","v5.10.166","v5.10.165","v5.10.164","v5.10.163","v5.10.162","v5.10.161","v5.10.160","v5.10.159","v5.10.158","v5.10.157","v5.10.156","v5.10.155","v5.10.154","v5.10.153","v5.10.152","v5.10.151","v5.10.150","v5.10.149","v5.10.148","v5.10.147","v5.10.146","v5.10.145","v5.10.144","v5.10.143","v5.10.142","v5.10.141","v5.10.140","v5.10.139","v5.10.138","v5.10.137","v5.10.136","v5.10.135","v5.10.134","v5.10.133","v5.10.132","v5.10.131","v5.10.130","v5.10.129","v5.10.128","v5.10.127","v5.10.126","v5.10.125","v5.10.124","v5.10.123","v5.10.122","v5.10.121","v5.10.120","v5.10.119","v5.10.118","v5.10.117","v5.10.116","v5.10.115","v5.10.114","v5.10.113","v5.10.112","v5.10.111","v5.10.110","v5.10.109","v5.10.108","v5.10.107","v5.10.106","v5.10.105","v5.10.104","v5.10.103","v5.10.102","v5.10.101","v5.10.100","v5.10.99","v5.10.98","v5.10.97","v5.10.96","v5.10.95","v5.10.94","v5.10.93","v5.10.92","v5.10.91","v5.10.90","v5.10.89","v5.10.88","v5.10.87","v5.10.86","v5.10.85","v5.10.84","v5.10.83","v5.10.82","v5.10.81","v5.10.80","v5.10.79","v5.10.78","v5.10.77","v5.10.76","v5.10.75","v5.10.74","v5.10.73","v5.10.72","v5.10.71","v5.10.70","v5.10.69","v5.10.68","v5.10.67","v5.10.66","v5.10.65","v5.10.64","v5.10.63","v5.10.62","v5.10.61","v5.10.60","v5.10.59","v5.10.58","v5.10.57","v5.10.56","v5.10.55","v5.10.54","v5.10.53","v5.10.52","v5.10.51","v5.10.50","v5.10.49","v5.10.48","v5.10.47","v5.10.46","v5.10.45","v5.10.44","v5.10.43","v5.12.19","v5.12.18","v5.12.17","v5.12.16","v5.12.15","v5.12.14","v5.12.13","v5.12.12","v5.12.11","v5.12.10"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-41040.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixe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