{"id":"CVE-2022-48976","state":"PUBLISHED","title":"netfilter: flowtable_offload: fix using __this_cpu_add in preemptible","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: flowtable_offload: fix using __this_cpu_add in preemptible\n\nflow_offload_queue_work() can be called in workqueue without\nbh disabled, like the call trace showed in my act_ct testing,\ncalling NF_FLOW_TABLE_STAT_INC() there would cause a call\ntrace:\n\n  BUG: using __this_cpu_add() in preemptible [00000000] code: kworker/u4:0/138560\n  caller is flow_offload_queue_work+0xec/0x1b0 [nf_flow_table]\n  Workqueue: act_ct_workqueue tcf_ct_flow_table_cleanup_work [act_ct]\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x33/0x46\n   check_preemption_disabled+0xc3/0xf0\n   flow_offload_queue_work+0xec/0x1b0 [nf_flow_table]\n   nf_flow_table_iterate+0x138/0x170 [nf_flow_table]\n   nf_flow_table_free+0x140/0x1a0 [nf_flow_table]\n   tcf_ct_flow_table_cleanup_work+0x2f/0x2b0 [act_ct]\n   process_one_work+0x6a3/0x1030\n   worker_thread+0x8a/0xdf0\n\nThis patch fixes it by using NF_FLOW_TABLE_STAT_INC_ATOMIC()\ninstead in flow_offload_queue_work().\n\nNote that for FLOW_CLS_REPLACE branch in flow_offload_queue_work(),\nit may not be called in preemptible path, but it's good to use\nNF_FLOW_TABLE_STAT_INC_ATOMIC() for all cases in\nflow_offload_queue_work().","publishedAt":"2024-10-21T20:05:55.739Z","updatedAt":"2026-05-23T15:21:14.168Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b038177636f83bbf87c2b238706474145dd2cd04","status":"affected","lessThan":"a220a11fda012fba506b35929672374c2723ae6d","versionType":"git"},{"version":"b038177636f83bbf87c2b238706474145dd2cd04","status":"affected","lessThan":"a81047154e7ce4eb8769d5d21adcbc9693542a79","versionType":"git"},{"version":"5345d78ae64d5a760c211cd2da995dc71c5b29e4","status":"affected","versionType":"git"},{"version":"5.15.157","status":"affected","lessThan":"5.16","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_flow_table_offload.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.0","versionType":"semver"},{"version":"6.0.13","status":"unaffected","lessThanOrEqual":"6.0.*","versionType":"semver"},{"version":"6.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_flow_table_offload.c"]}],"references":["https://git.kernel.org/stable/c/a220a11fda012fba506b35929672374c2723ae6d","https://git.kernel.org/stable/c/a81047154e7ce4eb8769d5d21adcbc9693542a79"],"weaknesses":[],"ingestedAt":"2026-10-29T20:05:26.763Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2022/48xxx/CVE-2022-48976.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2022-48976","state":"PUBLISHED","datePublished":"2024-10-21T20:05:55.739Z","dateUpdated":"2026-05-23T15:21:14.168Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-08-22T01:27:53.632Z"},"containers":{"cna":{"title":"netfilter: flowtable_offload: fix using __this_cpu_add in preemptible","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfilter: flowtable_offload: fix using __this_cpu_add in preemptible\n\nflow_offload_queue_work() can be called in workqueue without\nbh disabled, like the call trace showed in my act_ct testing,\ncalling NF_FLOW_TABLE_STAT_INC() there would cause a call\ntrace:\n\n  BUG: using __this_cpu_add() in preemptible [00000000] code: kworker/u4:0/138560\n  caller is flow_offload_queue_work+0xec/0x1b0 [nf_flow_table]\n  Workqueue: act_ct_workqueue tcf_ct_flow_table_cleanup_work [act_ct]\n  Call Trace:\n   <TASK>\n   dump_stack_lvl+0x33/0x46\n   check_preemption_disabled+0xc3/0xf0\n   flow_offload_queue_work+0xec/0x1b0 [nf_flow_table]\n   nf_flow_table_iterate+0x138/0x170 [nf_flow_table]\n   nf_flow_table_free+0x140/0x1a0 [nf_flow_table]\n   tcf_ct_flow_table_cleanup_work+0x2f/0x2b0 [act_ct]\n   process_one_work+0x6a3/0x1030\n   worker_thread+0x8a/0xdf0\n\nThis patch fixes it by using NF_FLOW_TABLE_STAT_INC_ATOMIC()\ninstead in flow_offload_queue_work().\n\nNote that for FLOW_CLS_REPLACE branch in flow_offload_queue_work(),\nit may not be called in preemptible path, but it's good to use\nNF_FLOW_TABLE_STAT_INC_ATOMIC() for all cases in\nflow_offload_queue_work()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b038177636f83bbf87c2b238706474145dd2cd04","status":"affected","lessThan":"a220a11fda012fba506b35929672374c2723ae6d","versionType":"git"},{"version":"b038177636f83bbf87c2b238706474145dd2cd04","status":"affected","lessThan":"a81047154e7ce4eb8769d5d21adcbc9693542a79","versionType":"git"},{"version":"5345d78ae64d5a760c211cd2da995dc71c5b29e4","status":"affected","versionType":"git"},{"version":"5.15.157","status":"affected","lessThan":"5.16","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_flow_table_offload.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.0","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.0","versionType":"semver"},{"version":"6.0.13","status":"unaffected","lessThanOrEqual":"6.0.*","versionType":"semver"},{"version":"6.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/netfilter/nf_flow_table_offload.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/a220a11fda012fba506b35929672374c2723ae6d"},{"url":"https://git.kernel.org/stable/c/a81047154e7ce4eb8769d5d21adcbc9693542a79"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-23T15:21:14.168Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.0.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.0","versionEndExcluding":"6.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.157"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2022-48976","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2024-10-22T13:18:28.477565Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-10-22T13:18:44.516Z"}}]}}}