CVE-2025-21959

Aliases:UBUNTU-CVE-2025-21959DEBIAN-CVE-2025-21959
Advisory lineage Upstream: 0 Downstream: 57
Modified
Published: 01 Apr 2025, 15:46
Last modified:08 Sept 2026, 08:41

Vulnerability Summary

Overall Risk (default)
medium
29/100
CVSS Score
7.3 HIGH
v3.1 (cve.org)
EPSS Score
0.43% LOW
0% probability +0.32%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

01 Apr 2025, 15:46
Published
Vulnerability first disclosed
08 Sept 2026, 08:41
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_conncount: Fully initialize struct nf_conncount_tuple in insert_tree() Since commit b36e4523d4d5 ("netfilter: nf_conncount: fix garbage collection confirm race"), `cpu` and `jiffies32` were introduced to the struct nf_conncount_tuple. The commit made nf_conncount_add() initialize `conn->cpu` and `conn->jiffies32` when allocating the struct. In contrast, count_tree() was not changed to initialize them. By commit 34848d5c896e ("netfilter: nf_conncount: Split insert and traversal"), count_tree() was split and the relevant allocation code now resides in insert_tree(). Initialize `conn->cpu` and `conn->jiffies32` in insert_tree(). BUG: KMSAN: uninit-value in find_or_evict net/netfilter/nf_conncount.c:117 [inline] BUG: KMSAN: uninit-value in __nf_conncount_add+0xd9c/0x2850 net/netfilter/nf_conncount.c:143 find_or_evict net/netfilter/nf_conncount.c:117 [inline] __nf_conncount_add+0xd9c/0x2850 net/netfilter/nf_conncount.c:143 count_tree net/netfilter/nf_conncount.c:438 [inline] nf_conncount_count+0x82f/0x1e80 net/netfilter/nf_conncount.c:521 connlimit_mt+0x7f6/0xbd0 net/netfilter/xt_connlimit.c:72 __nft_match_eval net/netfilter/nft_compat.c:403 [inline] nft_match_eval+0x1a5/0x300 net/netfilter/nft_compat.c:433 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x426/0x2290 net/netfilter/nf_tables_core.c:288 nft_do_chain_ipv4+0x1a5/0x230 net/netfilter/nft_chain_filter.c:23 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626 nf_hook_slow_list+0x24d/0x860 net/netfilter/core.c:663 NF_HOOK_LIST include/linux/netfilter.h:350 [inline] ip_sublist_rcv+0x17b7/0x17f0 net/ipv4/ip_input.c:633 ip_list_rcv+0x9ef/0xa40 net/ipv4/ip_input.c:669 __netif_receive_skb_list_ptype net/core/dev.c:5936 [inline] __netif_receive_skb_list_core+0x15c5/0x1670 net/core/dev.c:5983 __netif_receive_skb_list net/core/dev.c:6035 [inline] netif_receive_skb_list_internal+0x1085/0x1700 net/core/dev.c:6126 netif_receive_skb_list+0x5a/0x460 net/core/dev.c:6178 xdp_recv_frames net/bpf/test_run.c:280 [inline] xdp_test_run_batch net/bpf/test_run.c:361 [inline] bpf_test_run_xdp_live+0x2e86/0x3480 net/bpf/test_run.c:390 bpf_prog_test_run_xdp+0xf1d/0x1ae0 net/bpf/test_run.c:1316 bpf_prog_test_run+0x5e5/0xa30 kernel/bpf/syscall.c:4407 __sys_bpf+0x6aa/0xd90 kernel/bpf/syscall.c:5813 __do_sys_bpf kernel/bpf/syscall.c:5902 [inline] __se_sys_bpf kernel/bpf/syscall.c:5900 [inline] __ia32_sys_bpf+0xa0/0xe0 kernel/bpf/syscall.c:5900 ia32_sys_call+0x394d/0x4180 arch/x86/include/generated/asm/syscalls_32.h:358 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/common.c:387 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:412 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:450 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Uninit was created at: slab_post_alloc_hook mm/slub.c:4121 [inline] slab_alloc_node mm/slub.c:4164 [inline] kmem_cache_alloc_noprof+0x915/0xe10 mm/slub.c:4171 insert_tree net/netfilter/nf_conncount.c:372 [inline] count_tree net/netfilter/nf_conncount.c:450 [inline] nf_conncount_count+0x1415/0x1e80 net/netfilter/nf_conncount.c:521 connlimit_mt+0x7f6/0xbd0 net/netfilter/xt_connlimit.c:72 __nft_match_eval net/netfilter/nft_compat.c:403 [inline] nft_match_eval+0x1a5/0x300 net/netfilter/nft_compat.c:433 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x426/0x2290 net/netfilter/nf_tables_core.c:288 nft_do_chain_ipv4+0x1a5/0x230 net/netfilter/nft_chain_filter.c:23 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xf4/0x400 net/netfilter/core.c:626 nf_hook_slow_list+0x24d/0x860 net/netfilter/core.c:663 NF_HOOK_LIST include/linux/netfilter.h:350 [inline] ip_sublist_rcv+0x17b7/0x17f0 net/ipv4/ip_input.c:633 ip_list_rcv+0x9ef/0xa40 net/ip ---truncated---

CVSS Metrics

  • v3.1•HIGH•Score: 7.3CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
  • v3.1•MEDIUM•Score: 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS Trends

Current EPSS score: 0.43%• Percentile: 37%

Techniques & Countermeasures

  • CWE-908•Use of Uninitialized Resource

    The product uses or accesses a resource that has not been initialized.

Affected Systems

  • debian•linux

    < 5.10.237-1 | < 6.1.133-1 | < 6.12.20-1 | < 6.12.20-1

  • debian•linux-6.1

    < 6.1.137-1~deb11u1

  • ubuntu•linux

    all | < 5.4.0-218.238 | < 5.15.0-142.152 | < 6.8.0-84.84

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    all | < 5.4.0-1147.157 | < 5.15.0-1086.93 | < 6.8.0-1039.41

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.15

    < 5.15.0-1086.93~20.04.1

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.4

    < 5.4.0-1147.157~18.04.1

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-6.5

    all

  • ubuntu•linux-aws-6.8

    < 6.8.0-1039.41~22.04.1

  • ubuntu•linux-aws-fips

    all | < 5.4.0-1147.157+fips1 | < 5.15.0-1086.93+fips1 | < 6.8.0-1039.41+fips1

  • ubuntu•linux-aws-hwe

    all

  • ubuntu•linux-azure

    all | all | < 5.4.0-1152.159 | < 5.15.0-1091.100 | < 6.8.0-1038.44

  • ubuntu•linux-azure-4.15

    all

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.15

    < 5.15.0-1091.100~20.04.1

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.4

    < 5.4.0-1152.159~18.04.1

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.11

    < 6.11.0-1018.18~24.04.1

  • ubuntu•linux-azure-6.2

    all

  • ubuntu•linux-azure-6.5

    all

  • ubuntu•linux-azure-6.8

    < 6.8.0-1036.42~22.04.1

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-azure-fde

    all | all

  • ubuntu•linux-azure-fde-5.19

    all

  • ubuntu•linux-azure-fde-6.2

    all

  • ubuntu•linux-azure-fips

    all | < 5.4.0-1153.160+fips1 | < 5.15.0-1091.100+fips1 | < 6.8.0-1040.46+fips1

  • ubuntu•linux-azure-nvidia

    < 6.8.0-1025.27

  • ubuntu•linux-bluefield

    all | < 5.4.0-1106.113 | < 5.15.0-1069.71

  • ubuntu•linux-fips

    all | < 5.4.0-1121.131 | < 5.15.0-142.152+fips1 | < 6.8.0-84.84+fips1

  • ubuntu•linux-gcp

    all | all | < 5.4.0-1150.159 | < 5.15.0-1085.94 | < 6.8.0-1040.42

  • ubuntu•linux-gcp-4.15

    all

  • ubuntu•linux-gcp-5.11

    all

  • ubuntu•linux-gcp-5.13

    all

  • ubuntu•linux-gcp-5.15

    < 5.15.0-1085.94~20.04.1

  • ubuntu•linux-gcp-5.19

    all

  • ubuntu•linux-gcp-5.3

    all

  • ubuntu•linux-gcp-5.4

    < 5.4.0-1150.159~18.04.1

  • ubuntu•linux-gcp-5.8

    all

  • ubuntu•linux-gcp-6.11

    < 6.11.0-1016.16~24.04.1

  • ubuntu•linux-gcp-6.2

    all

Showing first 50 affected entries in server-rendered view.

References (54)