Description
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.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
22bedad3ce112d5ca1eaf043d4990fa2ed698c87 to < 7f1564b2b2072b7aa1ac75350e9560a07c7a44fdaffected22bedad3ce112d5ca1eaf043d4990fa2ed698c87 to < fa40ebef69234e39ec2d26930d045f2fb9a8cb2baffected22bedad3ce112d5ca1eaf043d4990fa2ed698c87 to < 0fb7aa04c19eac4417f360a9f7611a60637bdaccaffected22bedad3ce112d5ca1eaf043d4990fa2ed698c87 to < 5a515d13e15536e82c5c7c83eb6cf5bc4827fee5affected22bedad3ce112d5ca1eaf043d4990fa2ed698c87 to < 3561442599804905c3defca241787cd4546e99a7affected22bedad3ce112d5ca1eaf043d4990fa2ed698c87 to < 30e8aee77899173a82ae5ed89f536c096f20aaebaffected22bedad3ce112d5ca1eaf043d4990fa2ed698c87 to < b6c72479748b7ea09f53ed64b223cee6463dc278affected22bedad3ce112d5ca1eaf043d4990fa2ed698c87 to < b33a534610067ade2bdaf2052900aaad99701353affected
Linux Linux
Default version status: affected
2.6.35affected0 to < 2.6.35unaffected5.4.291 to ≤ 5.4.*unaffected5.10.235 to ≤ 5.10.*unaffected5.15.179 to ≤ 5.15.*unaffected6.1.131 to ≤ 6.1.*unaffected6.6.83 to ≤ 6.6.*unaffected6.12.19 to ≤ 6.12.*unaffected6.13.7 to ≤ 6.13.*unaffected6.14 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/7f1564b2b2072b7aa1ac75350e9560a07c7a44fd ↗
- https://git.kernel.org/stable/c/fa40ebef69234e39ec2d26930d045f2fb9a8cb2b ↗
- https://git.kernel.org/stable/c/0fb7aa04c19eac4417f360a9f7611a60637bdacc ↗
- https://git.kernel.org/stable/c/5a515d13e15536e82c5c7c83eb6cf5bc4827fee5 ↗
- https://git.kernel.org/stable/c/3561442599804905c3defca241787cd4546e99a7 ↗
- https://git.kernel.org/stable/c/30e8aee77899173a82ae5ed89f536c096f20aaeb ↗
- https://git.kernel.org/stable/c/b6c72479748b7ea09f53ed64b223cee6463dc278 ↗
- https://git.kernel.org/stable/c/b33a534610067ade2bdaf2052900aaad99701353 ↗
- https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html ↗
- https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html ↗