Answer in brief
CVE-2022-50000 records a High severity (CVSS 7.8) vulnerability in netfilter: flowtable: fix stuck flows on cleanup due to pending work. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=c29f74e0df7a02b8303bcdce93a7c0132d62577a <8fbdec08dbf7d7ab8e35bdc65eb4394bc82d1e26 || >=c29f74e0df7a02b8303bcdce93a7c0132d62577a <89e135a36a9eb81412b5459df94a80995ce62eef || >=c29f74e0df7a02b8303bcdce93a7c0132d62577a <9afb4b27349a499483ae0134282cefd0c90f480f | 8fbdec08dbf7d7ab8e35bdc65eb4394bc82d1e26, 89e135a36a9eb81412b5459df94a80995ce62eef, 9afb4b27349a499483ae0134282cefd0c90f480f |
| Linux/Linuxgeneric | 5.5 | Not reported |
Published upstream
Jun 18, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 4, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: fix stuck flows on cleanup due to pending work To clear the flow table on flow table free, the following sequence normally happens in order: 1) gc_step work is stopped to disable any further stats/del requests. 2) All flow table entries are set to teardown state. 3) Run gc_step which will queue HW del work for each flow table entry. 4) Waiting for the above del work to finish (flush). 5) Run gc_step again, deleting all entries from the flow table. 6) Flow table is freed. But if a flow table entry already has pending HW stats or HW add work step 3 will not queue HW del work (it will be skipped), step 4 will wait for the pending add/stats to finish, and step 5 will queue HW del work which might execute after freeing of the flow table. To fix the above, this patch flushes the pending work, then it sets the teardown flag to all flows in the flowtable and it forces a garbage collector run to queue work to remove the flows from hardware, then it flushes this new pending work and (finally) it forces another garbage collector run to remove the entry from the software flowtable. Stack trace: [47773.882335] BUG: KASAN: use-after-free in down_read+0x99/0x460 [47773.883634] Write of size 8 at addr ffff888103b45aa8 by task kworker/u20:6/543704 [47773.885634] CPU: 3 PID: 543704 Comm: kworker/u20:6 Not tainted 5.12.0-rc7+ #2 [47773.886745] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009) [47773.888438] Workqueue: nf_ft_offload_del flow_offload_work_handler [nf_flow_table] [47773.889727] Call Trace: [47773.890214] dump_stack+0xbb/0x107 [47773.890818] print_address_description.constprop.0+0x18/0x140 [47773.892990] kasan_report.cold+0x7c/0xd8 [47773.894459] kasan_check_range+0x145/0x1a0 [47773.895174] down_read+0x99/0x460 [47773.899706] nf_flow_offload_tuple+0x24f/0x3c0 [nf_flow_table] [47773.907137] flow_offload_work_handler+0x72d/0xbe0 [nf_flow_table] [47773.913372] process_one_work+0x8ac/0x14e0 [47773.921325] [47773.921325] Allocated by task 592159: [47773.922031] kasan_save_stack+0x1b/0x40 [47773.922730] __kasan_kmalloc+0x7a/0x90 [47773.923411] tcf_ct_flow_table_get+0x3cb/0x1230 [act_ct] [47773.924363] tcf_ct_init+0x71c/0x1156 [act_ct] [47773.925207] tcf_action_init_1+0x45b/0x700 [47773.925987] tcf_action_init+0x453/0x6b0 [47773.926692] tcf_exts_validate+0x3d0/0x600 [47773.927419] fl_change+0x757/0x4a51 [cls_flower] [47773.928227] tc_new_tfilter+0x89a/0x2070 [47773.936652] [47773.936652] Freed by task 543704: [47773.937303] kasan_save_stack+0x1b/0x40 [47773.938039] kasan_set_track+0x1c/0x30 [47773.938731] kasan_set_free_info+0x20/0x30 [47773.939467] __kasan_slab_free+0xe7/0x120 [47773.940194] slab_free_freelist_hook+0x86/0x190 [47773.941038] kfree+0xce/0x3a0 [47773.941644] tcf_ct_flow_table_cleanup_work Original patch description and stack trace by Paul Blakey.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2022-50000 records a High severity (CVSS 7.8) vulnerability in netfilter: flowtable: fix stuck flows on cleanup due to pending work. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=c29f74e0df7a02b8303bcdce93a7c0132d62577a <8fbdec08dbf7d7ab8e35bdc65eb4394bc82d1e26 || >=c29f74e0df7a02b8303bcdce93a7c0132d62577a <89e135a36a9eb81412b5459df94a80995ce62eef || >=c29f74e0df7a02b8303bcdce93a7c0132d62577a <9afb4b27349a499483ae0134282cefd0c90f480f | 8fbdec08dbf7d7ab8e35bdc65eb4394bc82d1e26, 89e135a36a9eb81412b5459df94a80995ce62eef, 9afb4b27349a499483ae0134282cefd0c90f480f |
| Linux/Linuxgeneric | 5.5 | Not reported |
Published upstream
Jun 18, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 4, 2026
In the Linux kernel, the following vulnerability has been resolved: netfilter: flowtable: fix stuck flows on cleanup due to pending work To clear the flow table on flow table free, the following sequence normally happens in order: 1) gc_step work is stopped to disable any further stats/del requests. 2) All flow table entries are set to teardown state. 3) Run gc_step which will queue HW del work for each flow table entry. 4) Waiting for the above del work to finish (flush). 5) Run gc_step again, deleting all entries from the flow table. 6) Flow table is freed. But if a flow table entry already has pending HW stats or HW add work step 3 will not queue HW del work (it will be skipped), step 4 will wait for the pending add/stats to finish, and step 5 will queue HW del work which might execute after freeing of the flow table. To fix the above, this patch flushes the pending work, then it sets the teardown flag to all flows in the flowtable and it forces a garbage collector run to queue work to remove the flows from hardware, then it flushes this new pending work and (finally) it forces another garbage collector run to remove the entry from the software flowtable. Stack trace: [47773.882335] BUG: KASAN: use-after-free in down_read+0x99/0x460 [47773.883634] Write of size 8 at addr ffff888103b45aa8 by task kworker/u20:6/543704 [47773.885634] CPU: 3 PID: 543704 Comm: kworker/u20:6 Not tainted 5.12.0-rc7+ #2 [47773.886745] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009) [47773.888438] Workqueue: nf_ft_offload_del flow_offload_work_handler [nf_flow_table] [47773.889727] Call Trace: [47773.890214] dump_stack+0xbb/0x107 [47773.890818] print_address_description.constprop.0+0x18/0x140 [47773.892990] kasan_report.cold+0x7c/0xd8 [47773.894459] kasan_check_range+0x145/0x1a0 [47773.895174] down_read+0x99/0x460 [47773.899706] nf_flow_offload_tuple+0x24f/0x3c0 [nf_flow_table] [47773.907137] flow_offload_work_handler+0x72d/0xbe0 [nf_flow_table] [47773.913372] process_one_work+0x8ac/0x14e0 [47773.921325] [47773.921325] Allocated by task 592159: [47773.922031] kasan_save_stack+0x1b/0x40 [47773.922730] __kasan_kmalloc+0x7a/0x90 [47773.923411] tcf_ct_flow_table_get+0x3cb/0x1230 [act_ct] [47773.924363] tcf_ct_init+0x71c/0x1156 [act_ct] [47773.925207] tcf_action_init_1+0x45b/0x700 [47773.925987] tcf_action_init+0x453/0x6b0 [47773.926692] tcf_exts_validate+0x3d0/0x600 [47773.927419] fl_change+0x757/0x4a51 [cls_flower] [47773.928227] tc_new_tfilter+0x89a/0x2070 [47773.936652] [47773.936652] Freed by task 543704: [47773.937303] kasan_save_stack+0x1b/0x40 [47773.938039] kasan_set_track+0x1c/0x30 [47773.938731] kasan_set_free_info+0x20/0x30 [47773.939467] __kasan_slab_free+0xe7/0x120 [47773.940194] slab_free_freelist_hook+0x86/0x190 [47773.941038] kfree+0xce/0x3a0 [47773.941644] tcf_ct_flow_table_cleanup_work Original patch description and stack trace by Paul Blakey.
Quoted source text, attributed separately from HOL analysis.