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Fencer Vulns
medium 5.5

CVE-2022-49812 json

bridge: switchdev: Fix memory leaks when changing VLAN protocol

published 2025-05-01 18 mo ago modified 2026-11-05 3 d ago also EUVD-2025-12958

cvss
5.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 11%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

bridge: switchdev: Fix memory leaks when changing VLAN protocol

The bridge driver can offload VLANs to the underlying hardware either via switchdev or the 8021q driver. When the former is used, the VLAN is marked in the bridge driver with the 'BR_VLFLAG_ADDED_BY_SWITCHDEV' private flag.

To avoid the memory leaks mentioned in the cited commit, the bridge driver will try to delete a VLAN via the 8021q driver if the VLAN is not marked with the previously mentioned flag.

When the VLAN protocol of the bridge changes, switchdev drivers are notified via the 'SWITCHDEV_ATTR_ID_BRIDGE_VLAN_PROTOCOL' attribute, but the 8021q driver is also called to add the existing VLANs with the new protocol and delete them with the old protocol.

In case the VLANs were offloaded via switchdev, the above behavior is both redundant and buggy. Redundant because the VLANs are already programmed in hardware and drivers that support VLAN protocol change (currently only mlx5) change the protocol upon the switchdev attribute notification. Buggy because the 8021q driver is called despite these VLANs being marked with 'BR_VLFLAG_ADDED_BY_SWITCHDEV'. This leads to memory leaks [1] when the VLANs are deleted.

Fix by not calling the 8021q driver for VLANs that were already programmed via switchdev.

[1] unreferenced object 0xffff8881f6771200 (size 256): comm "ip", pid 446855, jiffies 4298238841 (age 55.240s) hex dump (first 32 bytes): 00 00 7f 0e 83 88 ff ff 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<00000000012819ac>] vlan_vid_add+0x437/0x750 [<00000000f2281fad>] __br_vlan_set_proto+0x289/0x920 [<000000000632b56f>] br_changelink+0x3d6/0x13f0 [<0000000089d25f04>] __rtnl_newlink+0x8ae/0x14c0 [<00000000f6276baf>] rtnl_newlink+0x5f/0x90 [<00000000746dc902>] rtnetlink_rcv_msg+0x336/0xa00 [<000000001c2241c0>] netlink_rcv_skb+0x11d/0x340 [<0000000010588814>] netlink_unicast+0x438/0x710 [<00000000e1a4cd5c>] netlink_sendmsg+0x788/0xc40 [<00000000e8992d4e>] sock_sendmsg+0xb0/0xe0 [<00000000621b8f91>] ____sys_sendmsg+0x4ff/0x6d0 [<000000000ea26996>] ___sys_sendmsg+0x12e/0x1b0 [<00000000684f7e25>] __sys_sendmsg+0xab/0x130 [<000000004538b104>] do_syscall_64+0x3d/0x90 [<0000000091ed9678>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

Patch / fix

  • Linux Linux 5.10.157, 5.15.80, 6.0.10, 6.1
  • linux Debian 14, Debian 13, Debian 12 6.0.10-1

debian advisories DEBIAN-CVE-2022-49812

  • linux Ubuntu 22.04 LTS 5.15.0-67.74
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1031.35
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1030.37
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1028.33
  • linux-ibm Ubuntu 22.04 LTS 5.15.0-1026.29
  • linux-kvm Ubuntu 22.04 LTS 5.15.0-1029.34
  • linux-azure Ubuntu 22.04 LTS 5.15.0-1034.41
  • linux-gkeop Ubuntu 22.04 LTS 5.15.0-1016.21

ubuntu advisories UBUNTU-CVE-2022-49812

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel-64kb SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS, SLE High Performance Computing 15 SP4-ESPOS 5.14.21-150400.24.167.1
  • kernel-syms SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.167.1
  • kernel-source SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +3 more 5.14.21-150400.24.167.1
  • kernel-default SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +7 more 5.14.21-150400.24.167.1
  • kernel-zfcpdump SLES 15 SP4-LTSS, Manager Server 4.3 5.14.21-150400.24.167.1
  • kernel-obs-build SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE High Performance Computing 15 SP4-LTSS +1 more 5.14.21-150400.24.167.1
  • kernel-default-base SLES for SAP 15 SP4, SLES 15 SP4-LTSS, SLE Micro 5.4 +5 more 5.14.21-150400.24.167.1.150400.24.84.1
  • kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.110.1

suse advisories SUSE-SU-2025:02262-1SUSE-SU-2025:02173-1SUSE-SU-2025:01966-1SUSE-SU-2025:01918-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-49812 updated cvss 4.4

kernel: bridge: switchdev: Fix memory leaks when changing VLAN protocol

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
3 d ago

Exploit prediction

0.21% chance of exploitation in the next 30 days, higher than 11% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-401 Missing Release of Memory after Effective Lifetime
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.