5.5

CVE-2022-48976: netfilter: flowtable_offload: fix using __this_cpu_add in preemptible

Analyzed
AliasesUBUNTU-CVE-2022-48976DEBIAN-CVE-2022-48976
Published 21-10-2024Last modified 23-05-2026

Vulnerability summary

CVE-2022-48976 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.20% chance of exploitation in the next 30 days, higher than 10.1% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 5.5, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
5.5/10
010
Medium · v3.1 (NVD)
EPSS score
0.20%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 1
RHSA-2023:2458

Timeline

  1. 21-10-2024
    PublishedVulnerability first disclosed.
  2. 23-05-2026
    Last modifiedVulnerability information updated.

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().

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.20%

Chance of exploitation in the next 30 days

Percentile

10%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.20% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu105 products
  • linuxAll versions (No fix recorded)
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-awsAll versions (No fix recorded)
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ b038177636f83bbf87c2b238706474145dd2cd04, < a220a11fda012fba506b35929672374c2723ae6d | ≥ b038177636f83bbf87c2b238706474145dd2cd04, < a81047154e7ce4eb8769d5d21adcbc9693542a79 | 5345d78ae64d5a760c211cd2da995dc71c5b29e4 | ≥ 5.15.157, < 5.16 | 6.0
  • linux_kernel≥ 5.15.157, < 6.0.13 | 6.11:rc1 | 6.11:rc2 | 6.11:rc3 | 6.11:rc4 | 6.11:rc5 | 6.11:rc6 | 6.11:rc7 | 6.11:rc8
Debian1 product
  • linux< 6.1.4-1

3 vendors · 108 products

References

6 links