net/sched: fix netdevice reference leaks in attach_default_qdiscs()
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 5 fixed, 2 without a fix
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: net/sched: fix netdevice reference leaks in attach_default_qdiscs() In attach_default_qdiscs(), if a dev has multiple queues and queue 0 fails to attach qdisc because there is no memory in attach_one_default_qdisc(). Then dev->qdisc will be noop_qdisc by default. But the other queues may be able to successfully attach to default qdisc. In this case, the fallback to noqueue process will be triggered. If the original attached qdisc is not released and a new one is directly attached, this will cause netdevice reference leaks. The following is the bug log: veth0: default qdisc (fq_codel) fail, fallback to noqueue unregister_netdevice: waiting for veth0 to become free. Usage count = 32 leaked reference. qdisc_alloc+0x12e/0x210 qdisc_create_dflt+0x62/0x140 attach_one_default_qdisc.constprop.41+0x44/0x70 dev_activate+0x128/0x290 __dev_open+0x12a/0x190 __dev_change_flags+0x1a2/0x1f0 dev_change_flags+0x23/0x60 do_setlink+0x332/0x1150 __rtnl_newlink+0x52f/0x8e0 rtnl_newlink+0x43/0x70 rtnetlink_rcv_msg+0x140/0x3b0 netlink_rcv_skb+0x50/0x100 netlink_unicast+0x1bb/0x290 netlink_sendmsg+0x37c/0x4e0 sock_sendmsg+0x5f/0x70 ____sys_sendmsg+0x208/0x280 Fix this bug by clearing any non-noop qdiscs that may have been assigned before trying to re-attach.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.8 and later | 5.10.142, 5.15.66, 5.19.8, 6.0 | Patch available | CNA |
- Linux VendorLinux Affected 5.8 and later Fixed in 5.10.142, 5.15.66, 5.19.8, 6.0 Patch available CNA
CPE configurations NVD · 4
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.8 to before 5.10.142; 5.11 to before 5.15.66; 5.16 to before 5.19.8 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:* | 6.0 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:* | 6.0 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:6.0:rc3:*:*:*:*:*:* | 6.0 rc3 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.8 to before 5.10.142; 5.11 to before 5.15.66; 5.16 to before 5.19.8 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.0:rc1:*:*:*:*:*:* Versions 6.0 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.0:rc2:*:*:*:*:*:* Versions 6.0 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:6.0:rc3:*:*:*:*:*:* Versions 6.0 rc3 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.142, 5.15.66, 5.19.8, 6.0
Red Hat 2 advisories
- RHSA-2023:2951 Released 2023-05-16 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-477.10.1.el8_8, kernel-4.18.0-477.10.1.el8_8, kernel-abi-stablelists-4.18.0-477.10.1.el8_8 +19
- Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-477.10.1.el8_8
- 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 8 | Affected | No fix yet |
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2023:2458 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2023:2951 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2023:2458 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2023:2951 |
| Red Hat Enterprise Linux CRB (v. 9) | Fixed | RHSA-2023:2458 |
Not affected: 3 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2022-49958
- 2026-10-03 Alias added: GHSA-84fm-g3cv-66r3
References
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- 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-2022-49958 · CVE Program
- CVE-2022-49958 · NVD
- FIRST EPSS
- GHSA-84fm-g3cv-66r3 · GitHub Advisory Database · CC BY 4.0
- CVE-2022-49958 · 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