CVE-2022-49958

MEDIUM EPSS 10.5%
Published Jun 18, 20251y ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Jun 18, 2025 1y ago
Last Modified Jun 17, 2026 1w ago

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 Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
10.5% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Affected Products 6

VendorProductVersionRange
linuxlinux_kernel*≥5.8  –  <5.10.142
linuxlinux_kernel*≥5.11  –  <5.15.66
linuxlinux_kernel*≥5.16  –  <5.19.8
linuxlinux_kernel6.0any
linuxlinux_kernel6.0any
linuxlinux_kernel6.0any

References 4

  • git.kernel.org https://git.kernel.org/stable/c/0c6c522857151ac00150fd01baeebf231fb7d142
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/44dfa645895a56f65461249deb5b81cd16560e2a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a420d587260185407eda9c5766cfa9bdd5c39a56
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f612466ebecb12a00d9152344ddda6f6345f04dc
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/0c6c522857151ac00150fd01baeebf231fb7d142
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/44dfa645895a56f65461249deb5b81cd16560e2a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/a420d587260185407eda9c5766cfa9bdd5c39a56
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f612466ebecb12a00d9152344ddda6f6345f04dc
    Patch