{"id":"CVE-2026-74660","revision":"f07ad923e3f34e6795594fa2d43d5111","records":[{"revision":"f07ad923e3f34e6795594fa2d43d5111","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-74660","aliases":[],"title":"netfilter: ebt_nflog: pin the NFLOG backend","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: ebt_nflog: pin the NFLOG backend\n\nnf_log_unregister() runs after the per-net teardown so its final RCU\ngrace period also drains readers that obtained the logger from a per-net\nbinding.  However, ebt_nflog passes an explicit ULOG log type to\nnf_log_packet() without holding a reference on the selected logger module,\nunlike the xt_NFLOG and nft_log frontends.\n\nAn ebtables nflog rule can therefore remain callable while nfnetlink_log\nis unloaded.  The resulting interleaving is:\n\n  CPU 0                               CPU 1\n  nfnetlink_log_fini()\n    unregister_pernet_subsys()\n      kfree(nfnl_log_pernet(net))\n                                      ebt_nflog_tg()\n                                        nf_log_packet()\n                                          nfulnl_log_packet()\n                                            instance_lookup_get_rcu()\n\nThe global ULOG logger is still registered at this point, so CPU 1\ndereferences the per-net state after CPU 0 has freed it.  KASAN reported:\n\n  BUG: KASAN: slab-use-after-free in instance_lookup_get_rcu\n  Read of size 8 at addr ff110001052e6210 by task poc/92\n  Call Trace:\n   instance_lookup_get_rcu+0x1ce/0x1f0 [nfnetlink_log]\n   nfulnl_log_packet+0x248/0x2fb0 [nfnetlink_log]\n   nf_log_packet+0x204/0x300\n   ebt_nflog_tg+0x351/0x550\n   ebt_do_table+0xedf/0x22b0\n  Allocated by task 90:\n   __kmalloc_noprof+0x186/0x470\n   ops_init+0x6d/0x420\n   register_pernet_operations+0x2f6/0x670\n   register_pernet_subsys+0x23/0x40\n  Freed by task 93:\n   kfree+0x131/0x3c0\n   ops_undo_list+0x3e3/0x700\n   unregister_pernet_operations+0x232/0x490\n   unregister_pernet_subsys+0x1c/0x30\n   nfnetlink_log_fini+0x34/0x450 [nfnetlink_log]\n\nAcquire the ULOG logger module reference when an ebt_nflog rule is\nvalidated and release it when the rule is destroyed.  Request the NFLOG\nbackend for legacy callers when needed, matching xt_NFLOG.  This prevents\nmodule teardown until all ebt_nflog rules have stopped using the logger.","state":0,"publishedAt":"2026-08-22T15:32:33.677+00:00","modifiedAt":"2026-10-16T19:16:07.659+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/bridge/netfilter/ebt_nflog.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"c83fa19603bdaeef17b815713dbbe3230c8a34ee\",\n                            \"lessThan\": \"3bcce49d617c593c7606083bfdb464a1761fa68d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c83fa19603bdaeef17b815713dbbe3230c8a34ee\",\n                            \"lessThan\": \"394d7939c6b2b9e6bea0844c89efb5913168d898\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c83fa19603bdaeef17b815713dbbe3230c8a34ee\",\n                            \"lessThan\": \"2cac4294f184c9bc19ff82552c62b80498694c39\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c83fa19603bdaeef17b815713dbbe3230c8a34ee\",\n                            \"lessThan\": \"9d8a94b48b393885e7f876c8ef68ed4da5012078\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c83fa19603bdaeef17b815713dbbe3230c8a34ee\",\n                            \"lessThan\": \"6809379a860b9fccbb5435bf08343f6d081ac68d\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c83fa19603bdaeef17b815713dbbe3230c8a34ee\",\n                            \"lessThan\": \"47a119ec8a7e2d5c8c4e86fb1a56c4e696e500fb\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c83fa19603bdaeef17b815713dbbe3230c8a34ee\",\n                            \"lessThan\": \"e2ab7e878bdbe80104c879c31fd2d82a476703b8\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"c83fa19603bdaeef17b815713dbbe3230c8a34ee\",\n                            \"lessThan\": \"30825970339c107bacaf7f61af90fcdb1f597ca1\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"net/bridge/netfilter/ebt_nflog.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.12\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.12\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.265\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.216\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.183\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.152\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.104\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.45\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.1.9\",\n                            \"lessThanOrEqual\": \"7.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/3bcce49d617c593c7606083bfdb464a1761fa68d","https://git.kernel.org/stable/c/394d7939c6b2b9e6bea0844c89efb5913168d898","https://git.kernel.org/stable/c/2cac4294f184c9bc19ff82552c62b80498694c39","https://git.kernel.org/stable/c/9d8a94b48b393885e7f876c8ef68ed4da5012078","https://git.kernel.org/stable/c/6809379a860b9fccbb5435bf08343f6d081ac68d","https://git.kernel.org/stable/c/47a119ec8a7e2d5c8c4e86fb1a56c4e696e500fb","https://git.kernel.org/stable/c/e2ab7e878bdbe80104c879c31fd2d82a476703b8","https://git.kernel.org/stable/c/30825970339c107bacaf7f61af90fcdb1f597ca1"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-74660","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-74660","identifiers":["CVE-2026-74660"]},"retained":false,"historicalAffected":[]}],"coverage":[]}