cve-2026-64079

MEDIUM CVSS 5.5 nvd
Description

In the Linux kernel, the following vulnerability has been resolved: netfilter: x_tables: allocate hook ops while under mutex arp/ip(6)t_register_table() add the table to the per-netns list via xt_register_table() before allocating the per-netns hook ops copy via kmemdup_array(). This leaves a window where the table is visible in the list with ops=NULL. If the pernet exit happens runs concurrently the pre_exit callback finds the table via xt_find_table() and passes the NULL ops pointer to nf_unregister_net_hooks(), causing a NULL dereference: general protection fault in nf_unregister_net_hooks+0xbc/0x150 RIP: nf_unregister_net_hooks (net/netfilter/core.c:613) Call Trace: ipt_unregister_table_pre_exit iptable_mangle_net_pre_exit ops_pre_exit_list cleanup_net Fix by moving the ops allocation into the xtables core so the table is never in the list without valid ops. Also ensure the table is no longer processing packets before its torn down on error unwind. nf_register_net_hooks might have published at least one hook; call synchronize_rcu() if there was an error. audit log register message gets deferred until all operations have passed, this avoids need to emit another ureg message in case of error unwinding. Based on earlier patch by Tristan Madani.

Timeline
Published
2026-07-19
Last Modified
2026-09-03
CVSS Details
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
Affected Products
  • linux linux_kernel
Weaknesses (CWE)
CVSS metrics
Version Base Severity Vector Exploitability Impact Source
3.1 5.5 MEDIUM CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H 1.8 3.6 nvd@nist.gov
CPE configurations
OR
CPE Version range Vulnerable
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* >= 5.13, < 7.0.11 yes
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* — yes
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* — yes
cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* — yes
NVD metadata
NVD status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
Linked Vulnerabilities

No linked vulnerabilities found.

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  "datePublished": "2026-07-19T16:17:48.503",
  "dateUpdated": "2026-09-03T13:09:11.007",
  "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: x_tables: allocate hook ops while under mutex\n\narp/ip(6)t_register_table() add the table to the per-netns list via\nxt_register_table() before allocating the per-netns hook ops copy\nvia kmemdup_array().  This leaves a window where the table is\nvisible in the list with ops=NULL.\n\nIf the pernet exit happens runs concurrently the pre_exit callback finds\nthe table via xt_find_table() and passes the NULL ops pointer to\nnf_unregister_net_hooks(), causing a NULL dereference:\n\n  general protection fault in nf_unregister_net_hooks+0xbc/0x150\n  RIP: nf_unregister_net_hooks (net/netfilter/core.c:613)\n  Call Trace:\n    ipt_unregister_table_pre_exit\n    iptable_mangle_net_pre_exit\n    ops_pre_exit_list\n    cleanup_net\n\nFix by moving the ops allocation into the xtables core so the table is\nnever in the list without valid ops.  Also ensure the table is no longer\nprocessing packets before its torn down on error unwind.\nnf_register_net_hooks might have published at least one hook; call\nsynchronize_rcu() if there was an error.\n\naudit log register message gets deferred until all operations have\npassed, this avoids need to emit another ureg message in case of\nerror unwinding.\n\nBased on earlier patch by Tristan Madani.",
  "id": "CVE-2026-64079",
  "raw": {
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      {
        "affectedData": [
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              "net/ipv4/netfilter/ip_tables.c",
              "net/ipv6/netfilter/ip6_tables.c",
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              "net/ipv6/netfilter/ip6_tables.c",
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    "descriptions": [
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        "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: x_tables: allocate hook ops while under mutex\n\narp/ip(6)t_register_table() add the table to the per-netns list via\nxt_register_table() before allocating the per-netns hook ops copy\nvia kmemdup_array().  This leaves a window where the table is\nvisible in the list with ops=NULL.\n\nIf the pernet exit happens runs concurrently the pre_exit callback finds\nthe table via xt_find_table() and passes the NULL ops pointer to\nnf_unregister_net_hooks(), causing a NULL dereference:\n\n  general protection fault in nf_unregister_net_hooks+0xbc/0x150\n  RIP: nf_unregister_net_hooks (net/netfilter/core.c:613)\n  Call Trace:\n    ipt_unregister_table_pre_exit\n    iptable_mangle_net_pre_exit\n    ops_pre_exit_list\n    cleanup_net\n\nFix by moving the ops allocation into the xtables core so the table is\nnever in the list without valid ops.  Also ensure the table is no longer\nprocessing packets before its torn down on error unwind.\nnf_register_net_hooks might have published at least one hook; call\nsynchronize_rcu() if there was an error.\n\naudit log register message gets deferred until all operations have\npassed, this avoids need to emit another ureg message in case of\nerror unwinding.\n\nBased on earlier patch by Tristan Madani."
      }
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    "id": "CVE-2026-64079",
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            "confidentialityImpact": "NONE",
            "integrityImpact": "NONE",
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            "scope": "UNCHANGED",
            "userInteraction": "NONE",
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        "source": "nvd@nist.gov",
        "type": "Primary"
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    ]
  },
  "severity": "MEDIUM",
  "source": "nvd",
  "title": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: x_tables: allocate hook ops while und..."
}
Enrichment data
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