netfilter: flowtable_offload: fix using __this_cpu_add in preemptible
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
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().
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.15.157 to before 5.16 | 5.16 | Patch available | CNA |
| Linux | Linux | 6.0 and later | 6.0.13, 6.1 | Patch available | CNA |
- Linux VendorLinux Affected 5.15.157 to before 5.16 Fixed in 5.16 Patch available CNA
- Linux VendorLinux Affected 6.0 and later Fixed in 6.0.13, 6.1 Patch available CNA
CPE configurations NVD · 9
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.15.157 to before 6.0.13 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:* | 6.11 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:* | 6.11 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:* | 6.11 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc4:*:*:*:*:*:* | 6.11 rc4 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc5:*:*:*:*:*:* | 6.11 rc5 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc6:*:*:*:*:*:* | 6.11 rc6 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc7:*:*:*:*:*:* | 6.11 rc7 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.11:rc8:*:*:*:*:*:* | 6.11 rc8 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.15.157 to before 6.0.13 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc1:*:*:*:*:*:* Versions 6.11 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc2:*:*:*:*:*:* Versions 6.11 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc3:*:*:*:*:*:* Versions 6.11 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc4:*:*:*:*:*:* Versions 6.11 rc4 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc5:*:*:*:*:*:* Versions 6.11 rc5 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc6:*:*:*:*:*:* Versions 6.11 rc6 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc7:*:*:*:*:*:* Versions 6.11 rc7 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.11:rc8:*:*:*:*:*:* Versions 6.11 rc8 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.16
- Fix · CNA Linux (Linux) Fixed in 6.0.13, 6.1
Red Hat 1 advisory
- RHSA-2023:2458 Released 2023-05-09 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-284.11.1.el9_2, kernel-64k-debug-devel-matched-5.14.0-284.11.1.el9_2, kernel-64k-devel-5.14.0-284.11.1.el9_2 +10
- Red Hat Enterprise Linux BaseOS (v. 9) bpftool-7.0.0-284.11.1.el9_2, kernel-5.14.0-284.11.1.el9_2, kernel-64k-5.14.0-284.11.1.el9_2 +29
- Red Hat Enterprise Linux CRB (v. 9) kernel-tools-libs-devel-5.14.0-284.11.1.el9_2
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2023:2458 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2023:2458 |
| Red Hat Enterprise Linux CRB (v. 9) | Fixed | RHSA-2023:2458 |
Not affected: 3 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
Timeline
- 2026-10-02 Threatist record created from CVE-2022-48976
- 2026-10-03 Alias added: GHSA-3v5r-242w-7766
- 2026-10-29 Affected versions changed · Red Hat
References
More Linux Kernel vulnerabilities
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- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2022-48976 · CVE Program
- CVE-2022-48976 · NVD
- FIRST EPSS
- GHSA-3v5r-242w-7766 · GitHub Advisory Database · CC BY 4.0
- CVE-2022-48976 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences