Executive Summary



This vulnerability is currently undergoing analysis and not all information is available. Please check back soon to view the completed vulnerability summary
Informations
Name CVE-2022-49812 First vendor Publication 2025-05-01
Vendor Cve Last vendor Modification 2025-05-01

Security-Database Scoring CVSS v3

Cvss vector : N/A
Overall CVSS Score NA
Base Score NA Environmental Score NA
impact SubScore NA Temporal Score NA
Exploitabality Sub Score NA
 
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Security-Database Scoring CVSS v2

Cvss vector :
Cvss Base Score N/A Attack Range N/A
Cvss Impact Score N/A Attack Complexity N/A
Cvss Expoit Score N/A Authentication N/A
Calculate full CVSS 2.0 Vectors scores

Detail

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

Original Source

Url : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2022-49812

Sources (Detail)

https://git.kernel.org/stable/c/347f1793b573466424c550f2748ed837b6690fe7
https://git.kernel.org/stable/c/9d45921ee4cb364910097e7d1b7558559c2f9fd2
https://git.kernel.org/stable/c/f8926e2d2225eb7b7e11cd3fa266aaad9075b767
https://git.kernel.org/stable/c/fc16a2c81a3eb1cbba8775f5bdc67856df903a7c
Source Url

Alert History

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0
Date Informations
2025-05-27 02:12:02
  • First insertion