CVE-2022-48976

netfilter: flowtable_offload: fix using __this_cpu_add in preemptible

Published Oct 21, 2024 CVSS 3.1 · 5.5 Medium EPSS < 1% KEV · Not listed
Description
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().

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses NVD-CWE-noinfo
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc6:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc7:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.11:rc8:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Type Values Removed Values Added
Weaknesses CWE-362
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Description 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().
Title netfilter: flowtable_offload: fix using __this_cpu_add in preemptible
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
May 23, 2026, 3:21 PM
Reserved
Aug 22, 2024, 1:27 AM
Status
Analyzed
Published
Oct 21, 2024, 8:15 PM
Modified
Jun 17, 2026, 5:16 AM
Severity
Moderate
Public date
Oct 21, 2024, 12:00 AM