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TI-2025-15909 Aliases CVE-2025-21959GHSA-hwhh-xm47-jghm

netfilter: nf_conncount: Fully initialize struct nf_conncount_tuple in insert_tree()

Priority LOW 32CWE-908Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
Low · Low · Low
Fix status
Partial Red Hat: 3 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.

Summary

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---

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00447 39th percentileScored 2026-11-07
Fix Partial Linux (Linux): 4.15, 5.4.292, 5.10.236 +6Red Hat: 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux4.14.92 to before 4.154.15Patch availableCNA
LinuxLinux4.18 and later5.4.292, 5.10.236, 5.15.180, 6.1.132, 6.6.84, 6.12.20, 6.13.8, 6.14Patch availableCNA
  • Linux VendorLinux Affected 4.14.92 to before 4.15 Fixed in 4.15 Patch available CNA
  • Linux VendorLinux Affected 4.18 and later Fixed in 5.4.292, 5.10.236, 5.15.180, 6.1.132, 6.6.84, 6.12.20, 6.13.8, 6.14 Patch available CNA

CPE configurations NVD · 7

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*4.14.92 to before 4.15; 4.18 to before 5.4.292; 5.5 to before 5.10.236; 5.11 to before 5.15.180; 5.16 to before 6.1.132; 6.2 to before 6.6.84; 6.7 to before 6.12.20; 6.13 to before 6.13.8VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*6.14 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*6.14 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*6.14 rc3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*6.14 rc4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:*6.14 rc5VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:*6.14 rc6VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.14.92 to before 4.15; 4.18 to before 5.4.292; 5.5 to before 5.10.236; 5.11 to before 5.15.180; 5.16 to before 6.1.132; 6.2 to before 6.6.84; 6.7 to before 6.12.20; 6.13 to before 6.13.8 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:* Versions 6.14 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:* Versions 6.14 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:* Versions 6.14 rc3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:* Versions 6.14 rc4 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:* Versions 6.14 rc5 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:* Versions 6.14 rc6 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 4.15
  • Fix · CNA Linux (Linux) Fixed in 5.4.292, 5.10.236, 5.15.180, 6.1.132, 6.6.84, 6.12.20, 6.13.8, 6.14

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet: Fix deferred
Red Hat Enterprise Linux 8AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-21959
  2. 2026-10-03 Alias added: GHSA-hwhh-xm47-jghm

References

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources