9.8

CVE-2024-41040: net/sched: Fix UAF when resolving a clash

Modified
AliasesUBUNTU-CVE-2024-41040DEBIAN-CVE-2024-41040
Published 29-07-2024Last modified 05-08-2026

Vulnerability summary

CVE-2024-41040 is a critical (CVSS 9.8) Use After Free vulnerability in linux. EPSS estimates a 1.00% chance of exploitation in the next 30 days, higher than 62.8% of scored vulnerabilities.

Priority
Prioritisesevere

Severe, CVSS 9.8 (CVE.org); no exploitation reported by the 5 checked sources; EPSS 1% (FIRST, 03-11-2026)

Source freshness unavailable

How is this decided?
CVSS score
9.8/10
010
Critical · v3.1 (CVE.org)
EPSS score
1.00%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 30 · Related 20
DLA-4008-1DSA-5747-1MGASA-2024-0277MGASA-2024-0278RHSA-2024:6567RHSA-2024:7000

Timeline

  1. 29-07-2024
    PublishedVulnerability first disclosed.
  2. 05-08-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: Fix UAF when resolving a clash KASAN reports the following UAF: BUG: KASAN: slab-use-after-free in tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct] Read of size 1 at addr ffff888c07603600 by task handler130/6469 Call Trace: <IRQ> dump_stack_lvl+0x48/0x70 print_address_description.constprop.0+0x33/0x3d0 print_report+0xc0/0x2b0 kasan_report+0xd0/0x120 __asan_load1+0x6c/0x80 tcf_ct_flow_table_process_conn+0x12b/0x380 [act_ct] tcf_ct_act+0x886/0x1350 [act_ct] tcf_action_exec+0xf8/0x1f0 fl_classify+0x355/0x360 [cls_flower] __tcf_classify+0x1fd/0x330 tcf_classify+0x21c/0x3c0 sch_handle_ingress.constprop.0+0x2c5/0x500 __netif_receive_skb_core.constprop.0+0xb25/0x1510 __netif_receive_skb_list_core+0x220/0x4c0 netif_receive_skb_list_internal+0x446/0x620 napi_complete_done+0x157/0x3d0 gro_cell_poll+0xcf/0x100 __napi_poll+0x65/0x310 net_rx_action+0x30c/0x5c0 __do_softirq+0x14f/0x491 __irq_exit_rcu+0x82/0xc0 irq_exit_rcu+0xe/0x20 common_interrupt+0xa1/0xb0 </IRQ> <TASK> asm_common_interrupt+0x27/0x40 Allocated by task 6469: kasan_save_stack+0x38/0x70 kasan_set_track+0x25/0x40 kasan_save_alloc_info+0x1e/0x40 __kasan_krealloc+0x133/0x190 krealloc+0xaa/0x130 nf_ct_ext_add+0xed/0x230 [nf_conntrack] tcf_ct_act+0x1095/0x1350 [act_ct] tcf_action_exec+0xf8/0x1f0 fl_classify+0x355/0x360 [cls_flower] __tcf_classify+0x1fd/0x330 tcf_classify+0x21c/0x3c0 sch_handle_ingress.constprop.0+0x2c5/0x500 __netif_receive_skb_core.constprop.0+0xb25/0x1510 __netif_receive_skb_list_core+0x220/0x4c0 netif_receive_skb_list_internal+0x446/0x620 napi_complete_done+0x157/0x3d0 gro_cell_poll+0xcf/0x100 __napi_poll+0x65/0x310 net_rx_action+0x30c/0x5c0 __do_softirq+0x14f/0x491 Freed by task 6469: kasan_save_stack+0x38/0x70 kasan_set_track+0x25/0x40 kasan_save_free_info+0x2b/0x60 ____kasan_slab_free+0x180/0x1f0 __kasan_slab_free+0x12/0x30 slab_free_freelist_hook+0xd2/0x1a0 __kmem_cache_free+0x1a2/0x2f0 kfree+0x78/0x120 nf_conntrack_free+0x74/0x130 [nf_conntrack] nf_ct_destroy+0xb2/0x140 [nf_conntrack] __nf_ct_resolve_clash+0x529/0x5d0 [nf_conntrack] nf_ct_resolve_clash+0xf6/0x490 [nf_conntrack] __nf_conntrack_confirm+0x2c6/0x770 [nf_conntrack] tcf_ct_act+0x12ad/0x1350 [act_ct] tcf_action_exec+0xf8/0x1f0 fl_classify+0x355/0x360 [cls_flower] __tcf_classify+0x1fd/0x330 tcf_classify+0x21c/0x3c0 sch_handle_ingress.constprop.0+0x2c5/0x500 __netif_receive_skb_core.constprop.0+0xb25/0x1510 __netif_receive_skb_list_core+0x220/0x4c0 netif_receive_skb_list_internal+0x446/0x620 napi_complete_done+0x157/0x3d0 gro_cell_poll+0xcf/0x100 __napi_poll+0x65/0x310 net_rx_action+0x30c/0x5c0 __do_softirq+0x14f/0x491 The ct may be dropped if a clash has been resolved but is still passed to the tcf_ct_flow_table_process_conn function for further usage. This issue can be fixed by retrieving ct from skb again after confirming conntrack.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

1.00%

Chance of exploitation in the next 30 days

Percentile

63%

Versus all other CVEs

30-day change

No change 0.00 pp

From 1.00% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: network-reachable, no authentication, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu116 products
  • linux< 5.15.0-121.131 | < 6.8.0-44.44
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 5.15.0-1069.75 | < 6.8.0-1015.16
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ f07c548314776231f0d47d73ec6caa5b17e876e8, < b81a523d54ea689414f67c9fb81a5b917a41ed55 | ≥ 0cc254e5aa37cf05f65bcdcdc0ac5c58010feb33, < 2b4d68df3f57ea746c430941ba9c03d7d8b5a23f | ≥ 0cc254e5aa37cf05f65bcdcdc0ac5c58010feb33, < 4e71b10a100861fb27d9c5755dfd68f615629fae | ≥ 0cc254e5aa37cf05f65bcdcdc0ac5c58010feb33, < 799a34901b634008db4a7ece3900e2b971d4c932 | ≥ 0cc254e5aa37cf05f65bcdcdc0ac5c58010feb33, < ef472cc6693b16b202a916482df72f35d94bd69e | ≥ 0cc254e5aa37cf05f65bcdcdc0ac5c58010feb33, < 26488172b0292bed837b95a006a3f3431d1898c3 | 30822781c89943b6a3ed122324ceb37cea7042a3 | ≥ 5.10.43, < 5.10.222 | ≥ 5.12.10, < 5.13 | 5.13
  • linux_kernel≥ 5.10.43, < 5.10.222 | ≥ 5.12.10, < 5.13 | ≥ 5.13, < 5.15.163 | ≥ 5.16, < 6.1.100 | ≥ 6.2, < 6.6.41 | ≥ 6.7, < 6.9.10
Debian1 product
  • linux< 6.1.106-1 | < 6.9.10-1

3 vendors · 119 products

References

23 links
Show all 23 references