{"cve":"CVE-2024-41040","nvd":{"published":"2024-07-29T15:15:12.473","modified":"2026-08-04T11:19:21.393","status":"Modified","description":"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  <IRQ>\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  </IRQ>\n  <TASK>\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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.0},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/26488172b0292bed837b95a006a3f3431d1898c3","https://git.kernel.org/stable/c/2b4d68df3f57ea746c430941ba9c03d7d8b5a23f","https://git.kernel.org/stable/c/4e71b10a100861fb27d9c5755dfd68f615629fae","https://git.kernel.org/stable/c/799a34901b634008db4a7ece3900e2b971d4c932","https://git.kernel.org/stable/c/b81a523d54ea689414f67c9fb81a5b917a41ed55"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:53:51.317825789+00:00"},"epss":{"cve":"CVE-2024-41040","score":0.01,"percentile":0.62827,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}