https://db.gcve.eu/rss/recent/all/10 Most recent entries from all 2026-09-28T23:55:40.933125+00:00 Vulnerability-Lookup info@gcve.eu python-feedgen Contains only the most 10 recent entries. https://db.gcve.eu/vuln/cve-2022-48976 CVE-2022-48976 — netfilter: flowtable_offload: fix using __this_cpu_add in preemptible 2026-09-28T23:55:40.936014+00:00

Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

netfilter: flowtable_offload: fix using __this_cpu_add in preemptible

flow_offload_queue_work() can be called in workqueue without bh disabled, like the call trace showed in my act_ct testing, calling NF_FLOW_TABLE_STAT_INC() there would cause a call trace:

BUG: using __this_cpu_add() in preemptible [00000000] code: kworker/u4:0/138560 caller is flow_offload_queue_work+0xec/0x1b0 [nf_flow_table] Workqueue: act_ct_workqueue tcf_ct_flow_table_cleanup_work [act_ct] Call Trace: <TASK> dump_stack_lvl+0x33/0x46 check_preemption_disabled+0xc3/0xf0 flow_offload_queue_work+0xec/0x1b0 [nf_flow_table] nf_flow_table_iterate+0x138/0x170 [nf_flow_table] nf_flow_table_free+0x140/0x1a0 [nf_flow_table] tcf_ct_flow_table_cleanup_work+0x2f/0x2b0 [act_ct] process_one_work+0x6a3/0x1030 worker_thread+0x8a/0xdf0

This patch fixes it by using NF_FLOW_TABLE_STAT_INC_ATOMIC() instead in flow_offload_queue_work().

Note that for FLOW_CLS_REPLACE branch in flow_offload_queue_work(), it may not be called in preemptible path, but it's good to use NF_FLOW_TABLE_STAT_INC_ATOMIC() for all cases in flow_offload_queue_work().