5.5

CVE-2022-49958: net/sched: fix netdevice reference leaks in attach_default_qdiscs()

Analyzed
AliasesUBUNTU-CVE-2022-49958DEBIAN-CVE-2022-49958
Published 18-06-2025Last modified 11-05-2026

Vulnerability summary

CVE-2022-49958 is a medium (CVSS 5.5) vulnerability in linux. EPSS estimates a 0.25% chance of exploitation in the next 30 days, higher than 16.7% 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
0.25%
0%100%
Low · +0.01 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 6 · Related 4
RHSA-2023:2458RHSA-2023:2951SUSE-SU-2025:02264-1SUSE-SU-2025:02321-1SUSE-SU-2025:02322-1SUSE-SU-2025:02537-1

Timeline

  1. 18-06-2025
    PublishedVulnerability first disclosed.
  2. 11-05-2026
    Last modifiedVulnerability information updated.

Description

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.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

0.25%

Chance of exploitation in the next 30 days

Percentile

17%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.25% 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.

Ubuntu94 products
  • linux< 5.15.0-57.63
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 5.15.0-1027.31
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ bf6dba76d278d296b385b436d3ac7de56c190d44, < 44dfa645895a56f65461249deb5b81cd16560e2a | ≥ bf6dba76d278d296b385b436d3ac7de56c190d44, < a420d587260185407eda9c5766cfa9bdd5c39a56 | ≥ bf6dba76d278d296b385b436d3ac7de56c190d44, < 0c6c522857151ac00150fd01baeebf231fb7d142 | ≥ bf6dba76d278d296b385b436d3ac7de56c190d44, < f612466ebecb12a00d9152344ddda6f6345f04dc | 5.8
  • linux_kernel≥ 5.8, < 5.10.142 | ≥ 5.11, < 5.15.66 | ≥ 5.16, < 5.19.8 | 6.0:rc1 | 6.0:rc2 | 6.0:rc3
Debian1 product
  • linux< 6.0.2-1

3 vendors · 97 products

References

7 links