In the Linux kernel, the following vulnerability has been resolved:
vlan: enforce underlying device type
Currently, VLAN devices can be created on top of non-ethernet devices.
Besides the fact that it doesn't make much sense, this also causes a
bug which leaks the address of a kernel function to usermode.
When creating a VLAN device, we initialize GARP (garp_init_applicant)
and MRP (mrp_init_applicant) for the underlying device.
As part of the initialization process, we add the multicast address of
each applicant to the underlying device, by calling dev_mc_add.
__dev_mc_add uses dev->addr_len to determine the length of the new
multicast address.
This causes an out-of-bounds read if dev->addr_len is greater than 6,
since the multicast addresses provided by GARP and MRP are only 6
bytes long.
This behaviour can be reproduced using the following commands:
ip tunnel add gretest mode ip6gre local ::1 remote ::2 dev lo
ip l set up dev gretest
ip link add link gretest name vlantest type vlan id 100
Then, the following command will display the address of garp_pdu_rcv:
ip maddr show | grep 01:80:c2:00:00:21
Fix the bug by enforcing the type of the underlying device during VLAN
device initialization.
References
Configurations
Configuration 1 (hide)
|
History
11 Apr 2025, 13:13
| Type | Values Removed | Values Added |
|---|---|---|
| CWE | CWE-125 | |
| First Time |
Linux linux Kernel
Linux |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.1 |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:* |
|
| References | () https://git.kernel.org/stable/c/30e8aee77899173a82ae5ed89f536c096f20aaeb - Patch | |
| References | () https://git.kernel.org/stable/c/fa40ebef69234e39ec2d26930d045f2fb9a8cb2b - Patch | |
| References | () https://git.kernel.org/stable/c/3561442599804905c3defca241787cd4546e99a7 - Patch | |
| References | () https://git.kernel.org/stable/c/7f1564b2b2072b7aa1ac75350e9560a07c7a44fd - Patch | |
| References | () https://git.kernel.org/stable/c/5a515d13e15536e82c5c7c83eb6cf5bc4827fee5 - Patch | |
| References | () https://git.kernel.org/stable/c/0fb7aa04c19eac4417f360a9f7611a60637bdacc - Patch | |
| References | () https://git.kernel.org/stable/c/b6c72479748b7ea09f53ed64b223cee6463dc278 - Patch | |
| References | () https://git.kernel.org/stable/c/b33a534610067ade2bdaf2052900aaad99701353 - Patch |
01 Apr 2025, 16:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-04-01 16:15
Updated : 2025-04-11 13:13
NVD link : CVE-2025-21920
Mitre link : CVE-2025-21920
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-125
Out-of-bounds Read